History Characters / HalfLife

* [[Characters/HalfLifePlayerCharacters Player Characters]] [[labelnote:Click to Expand]] [[TheHero Dr. Gordon Freeman]], [[ActionSurvivor Barney Calhoun]], [[PerspectiveFlip Corporal Adrian Shephard]], [[AscendedExtra Gina Cross]], [[BloodKnight Colette Green]], [[ActionGirl Alyx Vance]] [[/labelnote]]

* [[Characters/HalfLifeSupportingCharacters Supporting Characters]][[labelnote:Click to Expand]] [[RebelLeader Dr. Eli Vance]], [[UnwittingInstigatorOfDoom Dr. Rosenberg]], [=D0G=], Dr. Isaac Kleiner, Lamarr, [[BitchInSheepsClothing Dr. Judith Mossman]], [[{{Jerkass}} Dr. Arne Magnusson]], [[BadassPreacher Father Grigori]], [[DirtyCoward Colonel Odessa Cubbage]], [[ThoseTwoGuys Griggs and Sheckley]], [[CoolOldGuy Russell]], [[MysteriousWatcher The G-Man]], Larry[[/labelnote]]

* [[Characters/HalfLifeTheCombine The Combine]][[labelnote:Click to Expand]] [[GreaterScopeVillain Shu'ulathoi/Advisors]], [[TheQuisling Dr. Wallace Breen]], The "Shadow Scientist," [[CannedOrdersOverLoudspeaker Overwatch Voice]], [[PoliceBrutality Civil Protection]], [[CyberneticsEatYourSoul Combine Overwatch]], [[AndIMustScream Stalkers]], Hunter-Chopper, Strider, Gunship, Hunter[[/labelnote]]
* [[Characters/HalfLifeOtherAntagonists Other Antagonists]][[labelnote:Click to Expand]][[SemperFi HECU]], [[SociopathicSoldier The Black Ops]], [[PlanetLooters Race X]], [[MysteriousBacker The "Employers"]][[/labelnote]]

* [[Characters/HalfLifeSupportingCharacters Supporting Characters]][[labelnote:Click to Expand]] [[RebelLeader Dr. Eli Vance]], [[UnwittingInstigatorOfDoom Dr. Rosenberg]], [=D0G=], Dr. Isaac Kleiner, Lamarr, Dr. Judith Mossman, [[{{Jerkass}} Dr. Arne Magnusson]], [[BadassPreacher Father Grigori]], [[DirtyCoward Colonel Odessa Cubbage]], [[ThoseTwoGuys Griggs and Sheckley]], [[CoolOldGuy Russell]], [[MysteriousWatcher The G-Man]], Larry[[/labelnote]]

* [[Characters/HalfLifeOtherAntagonists Other Antagonists]][[labelnote:Click to Expand]]HECU, The Black Ops, Race X, The "Employers"[[/labelnote]]

* [[Characters/HalfLifeXenAliens Xen Aliens]][[labelnote:Click to Expand]] [[FinalBoss Nihilanth]], [[WoobieSpecies Vortigaunts]], [[PersonalSpaceInvader Headcrabs]] and [[OurZombiesAreDifferent Zombies]], [[BigCreepyCrawlies Antlions]], Barnacles, Alien Grunt, Gargantua, Alien Controller, Houndeyes, Bullsquid, Alien Aircraft, [[PuzzleBoss Tentacle]], Snark, Ichthyosaur, Leeches, Jeff[[/labelnote]]
* [[Characters/HalfLifeTheCombine The Combine]][[labelnote:Click to Expand]]Shu'ulathoi/Advisors, Dr. Wallace Breen, The "Shadow Scientist," Overwatch Voice, Civil Protection, Combine Overwatch, Stalkers, Hunter-Chopper, Strider, Gunship, Hunter[[/labelnote]]

* [[Characters/HalfLifeXenAliens Xen Aliens]][[labelnote:Click to Expand]]Nihilanth, Vortigaunts, Headcrabs and Zombies, Antlions, Barnacles, Alien Grunt, Gargantua, Alien Controller, Houndeyes, Bullsquid, Alien Aircraft, Tentacle, Snark, Ichthyosaur, Leeches, Jeff[[/labelnote]]

* [[Characters/HalfLifePlayerCharacters Player Characters]] [[labelnote:Click to Expand]]Dr. Gordon Freeman, Barney Calhoun, Corporal Adrian Shephard, Gina Cross, Colette Green, Alyx Vance[[/labelnote]]
* [[Characters/HalfLifeSupportingCharacters Supporting Characters]][[labelnote:Click to Expand]]Dr. Eli Vance, Dr. Rosenberg, [=D0G=], Dr. Isaac Kleiner, Lamarr, Dr. Judith Mossman, Dr. Arne Magnusson, Father Grigori, Colonel Odessa Cubbage, Griggs and Sheckley, Russell, The G-Man, Larry[[/labelnote]]

* [[Characters/HalfLifeSupportingCharacters Supporting Characters]][[labelnote:Click to Expand]]Dr. Eli Vance, Dr. Rosenberg, D0G, Dr. Isaac Kleiner, Lamarr, Dr. Judith Mossman, Dr. Arne Magnusson, Father Grigori, Colonel Odessa Cubbage, Griggs and Sheckley, Russell, The G-Man, Larry[[/labelnote]]

* [[Characters/HalfLifePlayerCharacters Player Characters]]
* [[Characters/HalfLifeSupportingCharacters Supporting Characters]]
* [[Characters/HalfLifeXenAliens Xen Aliens]]
* [[Characters/HalfLifeTheCombine The Combine]]
* [[Characters/HalfLifeOtherAntagonists Other Antagonists]]

Characters from the ''VideoGame/HalfLife'' series.

'''''Warning: Here be heavy spoilers. More is to come.'''''

[[foldercontrol]]
!!Player Characters
[[folder:Dr. Gordon Freeman]]

[[quoteright:300:https://static.tvtropes.org/pmwiki/pub/images/rsz_half-life-gordon-freeman-alyx-vance-hd-wallpapers_979.jpg]]

->'''Age:''' 27.
->'''Education:''' [=PhD=] in Theoretical Physics, MIT.
->'''Employer and Position:''' Black Mesa Research Facility, Research Associate.
->'''Assignment:''' Anomalous Materials Laboratory.
->'''Clearance:''' Level 3.
->'''Administrative Sponsor:''' Classified.
->'''Disaster Response Priority:''' Discretionary.

--> ''We owe a great deal to Dr. Freeman, even if trouble does tend to follow in his wake.''
-->-- '''Dr. Kleiner''', whose description about Gordon's situation is reasonably accurate.

->'''Voiced by:''' [[HeroicMime Nobody]].[[note]]No, neither [[Machinima/FreemansMind Ross Scott]] nor [[Machinima/HalfLifeButTheAIisSelfAware WayneRadioTV]] count.[[/note]]

The main hero of the ''Half-Life'' series, Gordon Freeman is, at the point where ''Half-Life'' begins, a recently graduated scientist who is about half a hour late for an experiment, taking place deep within the Black Mesa Research Facility. If only he had known that it would soon become the least of his worries that day...

Finding himself at the ground zero of a disaster, trapped between an invasion of aggressive creatures from the dimension Xen and a shadowy military force that wants him and his colleagues dead, Freeman manages to battle his way across the facility in the span of two days, staying alive against all odds, aided by his HEV suit and staunch determination. He is eventually teleported to Xen, where he takes on the leader of the aliens, after which he finds himself face to face with the mysterious G-Man, who offers him a job.

Displaced by G-Man in time and space, Gordon suddenly finds himself in the so-called "City 17", in some undisclosed part of Eastern Europe two decades after the events at Black Mesa. He discovers that Earth has been conquered by an alien empire called "The Combine", who rules their new colony with an iron fist, and he quickly manages to run afoul of them and is soon hunted by their military. But he also finds out that some of his old friends from Black Mesa have organized a resistance group that fights against the regime, and that he himself has become a revered and famous figure for the rebels due to his actions at Black Mesa. Together with the resistance fighter Alyx Vance, he ignites a full-scale rebellion against the Combine and manages to bring down their central control-center on Earth.

In the wake of the overthrow of the Combine control, however, Gordon and Alyx, along with the rest of the rebels, soon find themselves engaged in an even more bloody and desperate struggle to defeat the remaining Combine forces on Earth, and, even more importantly, preventing them from contacting the empire proper for reinforcements.

* TheAce: A brilliant scientist who was hired by one of the most prestigious research institutions in the world before the age of 30, quickly becomes expertly skilled in almost all conventional and unconventional weaponry despite no prior military or weapons training (other than a basic run-through on the use of [=MP5=] in the Hazard Course), and consistently successful when fighting against overwhelming odds. When the Rebels have lost all hope and need an army to turn the tide, they look solely to Gordon. ''And he succeeds''.
* ActionSurvivor: Despite his legendary reputation come the second game, he was really just an Average (really smart) Joe minding his own business at a government job who was really good at adapting when the Incident happened. Even when he wakes up in the Combine era, he applies his resourcefulness despite not really knowing what's going on.
* AsskickingEqualsAuthority: By the time of ''Half-Life 2'', he doesn't have any definitive rank in the rebellion, but he pretty much commands any rebel squads he comes across, who are all too willing to ZergRush a position if he so much as looks at it, all because he's good at killing things.
* BadassBookworm: He's a graduate of MIT with a [=PhD=] in Theoretical Physics; his doctoral thesis is ludicrously titled ''"Observation of [[OurWormholesAreDifferent Einstein-Podolsky-Rosen]] Entanglement on [[TeleportersAndTransporters Supraquantum Structures]] by Induction Through Nonlinear [[GreenRocks Transuranic Crystal]] of Extremely Long Wavelength (ELW) Pulse from [[YourHeadAsplode Mode-Locked Source Array]]"''. In laymen's terms... looking at teleportation effects on crystals when you fire lasers at them. Which suspiciously sounds like the experiment you are conducting at the start.
* BadassBeard: Has a slick beard, and single-handedly wipes out armies of aliens and hostile soldiers.
* BadassNormal: Despite no prior military training or any superpowers, he regularly fights his way through highly trained special forces, augmented transhuman soldiers and super powered aliens.
* TheCameo: He pops up a couple of times as an NPC in the Gearbox expansion packs.
** In ''Opposing Force'', Shephard catches up to him just as he makes the jump into Xen.
** In ''Blue Shift'':
*** Gordon is in the tram right behind Barney's at the beginning of the game.
*** If Barney monkeys with the security cameras, he can see Gordon make his way to the lockers to pick up his HEV suit.
*** At the end of the game, Barney witnesses the HECU soldiers drag Gordon to the trash compactor due to a teleporter malfunction.
** [[spoiler:[[VideoGame/HalfLifeAlyx "'A previous hire has been unable--or unwilling--to perform the tasks laid before him...'"]] And he shows up again in the stinger--''[[SugarWiki/MomentOfAwesome as the player character]]''.]]
* ChildProdigy: According to his original biography, he constructed a butane-powered tennis ball cannon at the age of ''six.'' He began his career in science very early in life; he's earned a [=PhD=] in Theoretical Physics, despite being only 27 years old at the time of ''Half-Life''.
* CrowbarCombatant: He uses a crowbar as his melee weapon of choice, and is associated with it to the point he provides the trope image.
* DentedIron: [[spoiler:A look at [[https://combineoverwiki.net/images/3/3c/HLA_Gordon03.jpg his full model]] from ''Half-Life: Alyx'' shows his HEV suit (presumably from the ending of ''Episode 2'') to be quite battle damaged, including a sizable hole in the torso's midsection with his bandaged body visible underneath.]]
* DidYouJustPunchOutCthulhu:
** At the end of ''Half-Life 1'', he takes down [[spoiler:the Nihilanth]].
** The Rebels' reaction when he takes down his first Strider, and in ''Episode Two'' where he takes out an ''army'' of them.
* DivineIntervention: Well, more like "reality-altering shapeshifting alien intervention" -- as much of a badass as Freeman is, there have been a few times where he could have died, or even ''did'' outright die, only for the mysterious G-Man to intervene and keep him alive for his own reasons.
* TheDreaded:
** He steadily builds up a reputation throughout his adventures in ''Half-Life''; by the midpoint of the game, the marines know exactly who he is and are actively hunting for him specifically. By the end, the Nihilanth is able to directly address him by name.
--->'''Nihilanth''': '''''FREEEEEEEEEEEEEEMAAAAAAAAAAN...'''''
** By the second game, his fame has grown to such proportions that the mere sighting of him by Breen via accidental [[TeleporterAccident teleport hopping]] is enough to justify mobilizing the entire Combine Overwatch and yet they still underestimate him and get slaughtered in droves as a result.
* DudeWheresMyRespect: Averted. His reputation actually seems to do more work than him at times. He's definitely a badass by all standards, but his reputation reaches further than he does, inspiring and rallying the Resistance whether or not he does anything.
* {{Expy}}: In a way, of [[Film/TheArrival Zane Zaminsky]]. Both Zane and Gordon are bespectacled scientists with trim beards who end up targeted by alien forces and government cover-ups, though Gordon deals with his set of problems in a ''considerably'' [[OneManArmy more direct manner]].
* FamedInStory: By ''Half-Life 2'' and gains several names from the resistance.
* FeaturelessProtagonist: Although Gordon has a consistent appearance in official art, as a playable character, there is no point where Gordon's appearance is portrayed or even mentioned. While Gordon has a 3D model in the original ''Half-Life'' and its expansions, he is a FirstPersonGhost in ''Half-Life 2'' and its episodes. [[spoiler:This is finally averted in the ending of ''Half-Life: Alyx'' during the G-Man's speech, where he briefly shows you Gordon in-game, albeit in shadow.]]
* GeniusBruiser: The guy who blows up every hostile Xen and Combine thing he sees happens to be a graduate of MIT, with a doctorate in Theoretical Physics no less.
* HelmetsAreHardlyHeroic: In promotional artwork, his HEV suit doesn't have a helmet, unlike those worn by the bodies of the other dead scientists found scattered around Xen. Whether this is the case in gameplay or not is something that the fans have disputed for decades. [[spoiler:When the G-Man shows Alyx a vision of Freeman cloaked in shadow, he is clearly bareheaded.]]
* TheHero: The scientist who thwarts two alien invasions and is also the central hope against the Combine for humanity and the Vortigaunts.
* HeroAntagonist: To the HECU, and by extension the player character Adrian Shephard in ''Opposing Force''.
* HeroicMime: The whole time, which is also [[LampshadeHanging Lampshaded]] in the second game.
** Exception would be when he was breathing during the Black Mesa Incident, if that counts.
** In ''Half-Life 2'', Gordon also utters mild grunts of pain sometimes when he's on fire or falls from leg shattering heights.
** Alyx lampshades it early on when they meet: "Man of few words, aren't you?"
* HopeBringer: In ''VideoGame/HalfLife2'', Gordon's incredible feats have inspired both humanity and the Vortigaunts to form LaResistance against the Combine. In fact, the Resistance members fight alongside with Gordon late in the main game and its following Episodes.
* IconOfRebellion: In ''2'', his exploits have made him an almost mythological figure to the Resistance.
* ImplacableMan: Gordon Freeman didn't really ''mean'' to save the world by slaughtering hundreds of soldiers and aliens at Black Mesa. They were just in the way of the exit.
* InformedAbility: Gordon is a theoretical physicist, but the most technically complex things he does in the games are plug machinery in and solve rudimentary physics puzzles. Barney hangs a lampshade on that in the second game.
--> '''Barney:''' Good job, Gordon. Throwin' that switch and all? I can see your MIT education really pays for itself.
* IronicName: Gordon '''Free'''man spends most of the series as a puppet of the G-man's machinations.
* LightningBruiser: He can take quite a bit of punishment, thanks to the suit, but can also run at ridiculous speeds and carry more firepower than the entire 2nd Armored Division.
* LivingLegend: In the second game, as he was put into a statis by the G-Man. Most of the resistance knew him through passed stories, until he was placed in City 17 after years passed.
* LivingMacGuffin: [[spoiler:Partway into ''VideoGame/HalfLifeAlyx'', Eli and Alyx come to believe [[SealedGoodInACan Gordon is the one being held in the Vault]] and set out to release him. [[RedHerring Gordon is not the one in there, though.]]]]
* MeaningfulName: The Resistance and Vortigaunts often call him "The One Free Man", the name serving as inspiration in their own fight for freedom.
* MemeticBadass: InUniverse and out! Many characters from the second game easily associate him with his "expertise" in [[CrowbarCombatant crowbars]].
* MikeNelsonDestroyerOfWorlds: The entire Black Mesa Incident, specifically being told to force an alien crystal, that appeared out of nowhere, into the test chamber [[UnwittingInstigatorOfDoom that led every bit of the planet down under]]. Oh, [[spoiler:and [[VideoGame/HalfLife1 he killed off]] the LoadBearingBoss that was actively preventing [[NiceJobBreakingItHero the Combine from invading the planet]].]]
* OneManArmy: While his suit is a big part of it (it gives him about 4 times as much health as a regular soldier when fully charged, can automatically reload his holstered weapons, and applies morphine and other assistance to [[CriticalExistenceFailure keep him going at full strength even when badly wounded]]), it is still pretty amazing considering he is just a scientist. The best example is probably at the end of ''Episode Two''. [[spoiler:The rebel's main headquarters comes under attack from multiple directions. Dozens of Combine EliteMooks storm through the roof on dropships and set up numerous defensive positions, a bunch of [[LightningBruiser Hunters]] break in to support them, and a dozen striders, each supported by 2-3 Hunters, start attacking the base]]. After [[spoiler:the rebel personnel is completely slaughtered]], they just send Freeman, thinking that he's all they'll need to [[spoiler:repel hundreds of heavily armed and armored dark energy rifle wielding super soldiers, and a bunch of giant tripod death machines supported by dozens of other, smaller tripod death machines]]. [[CurbStompBattle They're right. Completely.]]
* OneRiotOneRanger: By ''Episode Two'' the Resistance sees him as nothing short than an [[PersonOfMassDestruction unstoppable god amongst men]], and he's often sent into the fray alone or with minimal help -- not because of Resistance laziness or cowardice, but because Freeman ''consistently'' wins and thrashes the Combine in the process single-handedly.
* PoweredArmor: His rechargeable HEV Suit, which provides damage mitigation, a Geiger counter, ammunition counter. The second game improves this by adding an Auxiliary power used for sprinting, oxygen monitoring, neurotoxin application, and a zoom-in feature like a binocular.
* RedBaron:
** Called "The One Free Man" by the Vortigaunts and rebels.
** [[TheDreaded "Anticitizen One"]], to the Combine.
* RightManInTheWrongPlace: The TropeNamer, as described by the G-Man, but not a straight example, because he's being manipulated by the G-Man.
* ScienceHero: PlayedWith. According to the backstory, Gordon has an MIT doctorate in theoretical physics, but he doesn't use his scientific knowledge to save the day. Instead, he uses his intelligence to solve puzzles and his weapons (usually the trusty crowbar and Gravity Gun) to fight the bad guys. It doesn't help that Gordon and the other Black Mesa scientists unwittingly caused the Resonance Cascade, [[spoiler:which is planned by the G-Man]]. Bottom-line: Gordon is this trope in-name and lore, but a straight forward ActionHero in-game, even if he [[NiceJobBreakingItHero accidentally messes things up]].
* SpecsOfAwesome: Gordon wears a pair of eye-glasses and he single-handedly defeated a psychic EldritchAbomination [[spoiler:(although doing so caught the Combine's attention)]], a [[TheDreaded dreaded]] [[TripodTerror tripod]], and [[spoiler:''an entire army of said tripods!'']]
* TrainingFromHell: His first combat experience saw him go from being a mild-mannered scientist to becoming an ActionSurvivor of a bloody catastrophe that left many of his friends and colleagues dead whilst pitting him against the United States government, hordes of savage monstrosities, and an entire extraterrestrial empire.
* UnderestimatingBadassery:
-->'''Dr. Breen''': [[CondescendingCompassion How could one man have slipped through your force's fingers time and time again? How is it possible?]] [[UnderestimatingBadassery This is not some agent provocateur or highly trained assassin we are discussing]]. [[BigStupidDoodooHead Gordon Freeman is a theoretical physicist who had hardly earned the distinction of his Ph.D. at the time of the Black Mesa Incident...]] [[InspirationalInsult the man you have consistently failed to slow, let alone capture, is by all standards simply that -- an ordinary man]].
* TheVoiceless: Implied. It's actually left ambiguous whether or not he can talk.
* WeaponOfChoice:
** His trademark weapon is a red crowbar he found in a tool kit at Black Mesa. Alternatively, he's also depicted wielding a pump-action shotgun.
** From ''Half-Life 2'' onwards, the Gravity Gun.
* WeDoTheImpossible: From researching, developing and testing portals and teleporters, to saving the planet from two invading alien races that came forth from dimensions opened by said portals.
[[/folder]]
[[folder:Barney Calhoun]]
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/Clipboard01_7670.png]]

->'''Age:''' [[Main/VagueAge Unknown.]]
->'''Education:''' 2 years Martinson College, Undecided Major.
->'''Employer and Position:''' Black Mesa Research Facility, Security Guard.
->'''Clearance:''' Level 3.
->'''Disaster Response Priority:''' Preservation of facility equipment and materials
->'''Secondary Priority:''' Welfare of research personnel
->'''Low Priority:''' Personal safety

-->

->Voice Actor: Mike Shapiro (English)[[note]]'''Other Languages''':Dmitry Filimonov (Russian)[[/note]]

->''"[[CallBack About that beer I owed ya]]! It's me Gordon! Barney from Black Mesa."''
The player character in ''[[VideoGame/HalfLifeBlueShift Blue Shift]]'', Barney Calhoun was a security guard at Black Mesa, and arrived to his duties at the same time as Gordon. Unlike Gordon and Adrian, he was the only player character in the first ''Half-Life'' not to have a special suit, and the only main character to escape from Black Mesa on his own, along with a few scientists.

In ''Half-Life 2'', Barney, posing as a Combine Civil Protection security guard, saves Gordon from heading to Nova Prospekt. He helps Gordon fight for the Resistance in City 17, and in ''Episode One'', he helps some of the residents evacuate. Last seen boarding a train outbound from City 17 by the end of ''Episode One'' with the help of Gordon and Alyx, his whereabouts are unknown in ''Episode Two''.
----

* AchievementsInIgnorance: Barney somehow manages to remain out of range from the G-Man and his employers despite not even being aware of them. Although it could simply be possible that the employers have little interest in hiring and/or detaining him, as the text simply says "no further comment" at the end of ''Blue Shift''.
* ActionSurvivor: His character arc in ''Blue Shift'' is simply surviving the incident and escaping the facility with some of the scientific staff. He faces less opposition than Freeman or Shephard (mostly fighting only Xen wildlife, Vortigaunts, and Marines, with only 4 Alien Grunts and 4 Controllers ever crossing his path), and there's not even a FinalBoss for him to fight. He does manage to take out a tank at one point, though.
* AscendedExtra: From being a stock security guard in ''Half-Life 1'' to the star of ''Blue Shift'' to a major character in ''Half-Life 2''.
* BadassNormal: Moreso than any of the other player characters. He went through ''Blue Shift'' with only security guard equipment, and unlike Gordon and Adrian, he isn't under surveillance by the G-Man.
* TheBigGuy: In ''Blue Shift'', he is this to the team of scientists led by Dr. Rosenberg. He is the only one of the lot without a doctorate, but conversely he's the only one who can knock down aliens and soldiers left and right.
* CallBack: In ''Half-Life'', Barney invites Dr. Freeman to join him on the firing range and grab a beer with him. In ''Half-Life 2'', he mentions he still owes Freeman a beer.
* CompositeCharacter: Barney Calhoun a combination of the protagonist of ''Blue Shift'' (the security guard seen banging on a locked door midway through Gordon's tram ride) and the random security guards throughout Half-Life; he mentions owing Gordon a beer at the start of ''Half Life 2'', a reference to random security guard chatter from before the Resonance Cascade.
* ConspiracyTheorist: Opening his locker in ''Blue Shift'' reveals that he's currently reading two books. One is actually titled ''Conspiracy Theories'', while the other is about aliens.
* CrowbarCombatant: Like Freeman, he stumbles across a crowbar during his trek through the wrecked portions of Black Mesa early in ''Blue Shift''. He uses it alongside his trusty pistol for most of the early segments of ''Blue Shift''. And it's implied that it's this same crowbar from Black Mesa that he hands over to Gordon at the start of ''Half-Life 2''.
* EarlyBirdCameo: He's the Security Guard seen knocking at a door when you're passing by with the tram in the very beginning of ''Half Life 1''.
* HeroicMime: Like all ''Half-Life'' playable characters save Alyx, he never speaks a word under your control. That doesn't mean he's not communicating, however, as the scientists he meets during the search for Dr. Rosenberg react to him as if he's asking for him.
* HeroOfAnotherStory: After we got his own experience of the direct aftermath of the resonance cascade in ''VideoGame/BlueShift'', he became one of the most active members of the Resistance against the Combine, working for years as a [[TheMole mole]] within the Civil Protection to exfiltrate citizens of City 17 to the outskirts and protecting Kleiner's lab. After Freeman reemerged and destroyed [[TheAlcatraz Nova Prospekt]], he led the Resistance troops in the battlegrounds of City 17 for over a week, and in ''Episode One'', helped organizing the evacuation of the remaining residents of the City before its annihilation by the Citadel's destabilized core, then left on a train to an unknown location, presumably continuing his adventure somewhere else.
* TheLancer: Fills the gap for Alyx in ''Half-Life 2'' during the chapter ''Follow Freeman!''
* NiceGuy: A trait he shares with most of the good guys.
* NotWorthKilling: Unlike Freeman or Shephard, he manages to escape Black Mesa due to not being noteworthy enough for the G-Man to interfere with his fate.
* OneManArmy: In ''Blue Shift''. In particular, he has a firefight against a very large group of Marines in a freight yard that easily matches any combat Freeman got into during his journey through Black Mesa.
* PrecisionFStrike: Gives one at the end of the chapter noted above. Of course, [[SoundEffectBleep it's censored by Dog closing the entrance into the Citadel that you just entered]], but the dialog is intact in the game files. Also, the subtitles censor a different portion of the word "fuck" than is covered by the audible crash.
-->'''Barney:''' And if you see Doctor Breen tell him I said "FUCK YOU!"
* PutOnABus: More accurately, the second-to-last train to leave City 17 at the end of ''Episode One.''
* TheMole: Works within Civil Protection and uses it as a means to help civilians escape from the city
* RebelLeader: He seems to be the rebels ''de facto'' field commander, behind in rank only to Eli and maybe Gordon.
* SuddenlyVoiced: As typical for protagonists in the series, he's a HeroicMime in ''Blue Shift'', but he talks as an NPC in ''Half-Life 2''.
* TookALevelInBadass: Barney handles himself well in ''Blue Shift'' (even surviving through Xen, for one), but when we meet up with him in the second game, he's one of the leaders of the Resistance, their mole in Civil Protection, and once the revolution hits the streets, a competent field commander.
* WhyDidItHaveToBeSnakes: He really doesn't like headcrabs, calling them "head humpers", and unfortunately for him, Dr. Kleiner keeps one named Lamarr as a pet, and Barney wishes Kleiner would just get rid of it.
[[/folder]]

[[folder:Corporal Adrian Shephard]]
[[quoteright:285:https://static.tvtropes.org/pmwiki/pub/images/shephard2_5.jpg]]
->'''Age:''' 22.
->'''Training:''' United States Marine Corps, Special Forces.
->'''Assignment:''' Hazardous Environment Combat Unit, Santiago, Arizona.
->'''Mission:''' Classified.

->'''Voiced by:''' [[TheVoiceless Nobody.]]

The player character in ''[[VideoGame/HalfLifeOpposingForce Opposing Force]]'', Adrian Shephard was one of the marines assigned to Black Mesa to do a full containment, taking out the witnesses, and finding Gordon Freeman. However, his transport was ambushed and shot down before he was given his mission, which leads him to work together with Black Mesa's scientists and security guards despite them becoming increasingly distrustful of him as the game progresses. In some of his attempts to escape and regroup with any members of his team, the G-Man both helped and hindered him along the way.

He was ultimately detained by the G-Man in AnotherDimension at the end of ''Opposing Force'', now pending further evaluation.
----
* BadassNormal: As with Freeman and Calhoun. In his case though, he manages to fight through and survive against a unit of highly-trained Black Ops agents ''and'' two simultaneous alien invasions.
* BeCarefulWhatYouWishFor: One of his diary entries from the game manual of ''Opposing Force'' has him saying that he wants to be part of a special reassignment and for a piece of action. And considering what happens once he's in Black Mesa, it's heavily implied that he regrets thinking this...
-->'''Shephard''': Another typically hellish day at base camp... I'll be glad when this is over and I can get assigned a mission. There has been this really weird civie spotted at the base. Rumor is he's from some government branch looking to recruit; others say he's with some secret research group. I would jump at the chance to join. It would be cool just for the change and the adventure.
* TheBigGuy: Is this compared to Freeman and Barney, as shown by the fact he starts with a slower, heavier hitting pipe wrench and [[PunchPackingPistol punch-packing Desert Eagle]], rather than the fast swinging crowbar and high-capacity Glock the other protagonists get. He's also apparently strong enough to make Vortigaunts ''explode'' with one overhead smash from the pipe wrench.
* BreakoutMookCharacter: In the main ''Half-Life'' game, the marines were just enemies to shoot at. In ''Opposing Force'', you play as one.
* ColdSniper: He receives training in the use of the M40 SniperRifle during boot camp, and manages to acquire one from the Black Ops late into the Black Mesa incident. And being the HeroicMime he is, all his kills with the weapon are done without him ever speaking a single word.
* CoolPet: One of his weapons is a Spore Launcher, which is a infant Shock Trooper, one of the Race X mooks, that he uses to shoot spores at enemy aliens. The reason it is considered a pet is that if the player is standing still long enough while equipping it, Shephard will actually pet it, with the Spore Launcher purring softly. Ironically, the Spore Launcher is one of the best weapons to use against [[EliteMook Shock Troopers]], as at least three shots can kill them.
* DeusExMachina: Early in the game, Shephard is trapped in a room which is increasingly filling up with toxic waste. The only reason he doesn't die is that the G-Man opens the door for him so he can escape.
* DiabolusExMachina: After fighting his way through hordes of aliens, Shephard finally reaches the evacuation point. The only reason he stays behind is that the G-Man closes the door to prevent him from escaping.
* TheFaceless: Has only two character art pictures of him, both with his gas mask on. His multiplayer image is just a generic HECU soldier.
* FingerlessGloves: Like all HECU Marines, he is issued these as part of his uniform.
* GasMaskMooks: Based on his picture, he's constantly wearing a gas mask.
* HeKnowsTooMuch: The G-Man knows Shephard has probably witnessed too much, which is why he decides to have him detained, despite his employers wanting him killed for it.
* KnifeNut: His second melee weapon is a combat knife. It swings as fast as Gordon's crowbar and deals as much damage as the pipe wrench, but it has no alternate attack unlike the latter.
* LateToTheTragedy: Unlike Gordon or Barney, who witness the Resonance Cascade and its immediate aftermath, Shephard is sent to Black Mesa a few hours later, only to be knocked unconscious when his transport is shot down by Xen Manta Rays. Worse still, he only awakens just as the HECU is giving out orders to pull out of Black Mesa, essentially leaving him clueless and wandering almost aimlessly about in search of an exit. Worse still, near the climax of the game he's among the very few surviving humans still in Black Mesa, with everyone else with dead or escaped, leaving him wedged between even more aliens than what Gordon and Barney had to fend off.
* LockedOutOfTheLoop: Played with. Unlike all the other squads, Shephard and his squad never receive the order to silence Black Mesa's surviving personnel. That being said, it's very likely that he eventually figured it out on his own; it's just that he wasn't really in much of a position to act on it even if he wanted to. Being caught in a MeleeATrois between two different alien invasions and squads of Black Ops assassins who have similar orders to silence ''you'' didn't leave him much of a choice but to fight for his life.
* LongBusTrip: Despite the facts that ''Opposing Force'' ends with Shephard in a state from which he could easily be brought back, and Gabe Newell himself having stated that Valve is planning to "bring him back one of these days", no mentioning of him has been made in any of the ''Half-Life'' sequels.
* OneManArmy: Carved a bloody path through Black Ops assassins, fought two simultaneous alien factions, and carried more weapons than Barney, Gina, Collette or even Gordon.
* PoweredArmor: His Powered Combat Vest, or PCV, which is more or less a military adaptation of the HEV. Like the HEV Suit used by Freeman and the Black Mesa Science Team, it protects its user from radiation, fire, toxic chemicals, blast damage and blunt force trauma, and also requires recharging from a compatible power supply station, though the PCV is compatible with anything that has a plug-in, even civilian ones. Unlike the HEV Suit, there is no ComputerVoice notifying the user, presumably due to this giving away the user's position in a warzone. The same reason applies to why the PCV uses night-vision instead of a regular flashlight. In his training, the drill instructor even demonstrates this by having a Marine fire a shotgun at him almost point-blank while he wears a fully powered vest.
--> "As you can see, you are not dead!"
* SemperFi: Like the rest of the HECU, he's shown to be extremely determined with regards to fighting the alien threats and trying to find a way out of Black Mesa.
* SleptThroughTheApocalypse: He's rendered unconscious at the start of the game and only comes to around the same time as the HECU decides to pull out of Black Mesa, which is during the second day of the invasion.
* SpaceMarine: Downplayed. Adrian Shephard is never in space. While his branch of the Marines is explicitly reserved for fighting aliens, he and his comrades remain planted firmly on Earth.
* SuicideMission: After G-Man hinders his one chance of escaping from Black Mesa, he ends up going deeper and deeper into the bowels of the facility. In the end, he goes to fight the Gene Worm despite knowing he will probably die.
* VillainProtagonist: While it's rather hard to call Adrian a "villain", he was actually working for HECU in order to [[LeaveNoSurvivors annihilate not only the aliens, but also the Black Mesa staff, the witnesses]] [[ArsonMurderAndJaywalking and Freeman himself]]. Regardless of the actual orders, his squad being shot down makes him unable to receive that order, and by the time he wakes up a day later the HECU is getting ready to cut their losses and pull out. Being left behind, he probably figured his actual orders but didn't follow to them to not have to fight the civilians as opposed to two different alien invasions and a Black Ops team sent to silence the survivors. The fact that the trailer for ''Blue Shift'' expansion pack features him with the text "''You played the villain''" may probably help, though...
* WalkingArmory: Over the course of his journey, he acquires a [[WrenchWhack pipe wrench]], a [[KnifeNut combat knife]], a {{Laser Sight}}ed [[HandCannon Desert Eagle]], several alien LivingWeapons, an [[ColdSniper M40 sniper rifle]], and various other CoolGuns.
* WhatTheHellHero: Shephard inevitably gets snarked at by the scientists by the time it's clear he wasn't sent there to save anyone.
* WrenchWhack: His initial melee weapon is a pipe wrench. Compared to Gordon's crowbar, it swings slower, but deals more damage and has an alternate attack that allows him to charge his swing for massive damage.
* YouRemindMeOfX: G-Man uses variant 1 towards Shephard, and mentions his ability to survive against all odds as the main reason. G-Man also mentions why he saved Shephard's life and argued against his employers' wishes to kill him.
[[/folder]]

[[folder:Gina Cross]]
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/250px-gina_cross_416.jpg]]

->'''Age:''' 25. [[labelnote:Note]]31 in unused files.[[/labelnote]]
->'''Employer and Position:''' Black Mesa Research Facility, Research Associate and Hazardous Environment Supervisor.
->'''Education:''' [=PhD=] in Bioengineering and Mechanical Engineering, Caltech. [[labelnote:Note]]Applied Physics in unused files.[[/labelnote]]
->'''Clearance:''' Level 4.
->'''Administrative Sponsor:''' Richard Keller. [[labelnote:Note]]Classified in unused files.[[/labelnote]]

-> Voice Actor: Kathy Levin

Dr. Gina Cross is one half of the protagonist team in ''VideoGame/HalfLifeDecay'' and a Black Mesa scientist. What happened to her after the events of ''Decay'' is unknown.
----
* ActionGirl: She battles her way through Black Mesa and kicks just as much ass as Gordon, Shephard, or Barney.
* AscendedExtra: A hologram of her as the Hazard Course Instructor appears in ''Half-Life'' and ''Opposing Force''. She can also be seen on security camera footage in ''Blue Shift'', and is one of the original multiplayer characters.
* RedOniBlueOni: The Blue Oni to Green's Red Oni.
* TheSmurfettePrinciple: She was the only female Black Mesa employee to appear in the first game, and only as a hologram in the tutorial.
* UncertainDoom: In ''Opposing Force'', a body resembling hers is found near one of the Displacer's Xen teleport locations, and said body has the file name "Gina.mdl". However, it's worth noting that said model was a standard one from ''Half-Life: Deathmatch'', and was created before ''Decay'', so her fate is ambiguous at best. Randy Pitchford confirmed that [[spoiler:the body was in fact Gina's in a response to [[https://twitter.com/DuvalMagic/status/1053746997113511936 the question on Twitter]]]], though her fate remains unconfirmed by Valve.
[[/folder]]

[[folder:Colette Green]]
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/250px-colette_green_7665.jpg]]

->'''Age:''' 31. [[labelnote:Note]]37 in unused files.[[/labelnote]]
->'''Employer and Position:''' Black Mesa Research Facility, Research Associate.
->'''Education:''' [=PhD=] in Electrical Engineering, Carnegie Mellon.
->'''Clearance:''' Level 4.
->'''Administrative Sponsor:''' Richard Keller. [[labelnote:Note]]Classified in unused files.[[/labelnote]]

-> Voice Actor: Lani Minella

Dr. Colette Green is one half of the protagonist team in ''VideoGame/HalfLifeDecay'' and a Black Mesa scientist. What happened to her after the events of ''Decay'' is unknown.
----
* ActionGirl: She battles her way through Black Mesa and kicks just as much ass as Gordon, Shephard, or Barney.
%%* BloodKnight
* RedOniBlueOni: The Red Oni to Cross' Blue Oni.
* WhatHappenedToTheMouse: Assuming the dead body found in ''Opposing Force'' really ''is'' Gina's, it's never made clear what happened to Colette. Pitchford even states they don't know what happened to her, albeit he claims that she might be in the G-Man's freezer with Adrian Shephard.
[[/folder]]

[[folder:Alyx Vance]]
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/alyxv_1183.png]]

-> Voice Actor: Merle Dandridge, Ozioma Akagha (''Half-Life: Alyx'') (English)[[note]]'''Other Languages''':Zhanna Nikonova (Russian)[[/note]]

->''"Doctor Freeman I presume?"''

The heroine of ''Half-Life 2'', Alyx Vance helped Gordon Freeman time and again in his work with the Resistance. She also follows Gordon the whole way throughout Episodes ''One'' and ''Two''.

She's also the main playable character of her eponymously subtitled VR interquel, ''VideoGame/HalfLifeAlyx'', making her the first ''Half-Life'' protagonist to be voiced (if one doesn't count Barney).
----
* ActionGirl: She was established as a badass resistance fighter in the ''Half-Life 2'' trilogy. Now, the player is able to play as a younger Alyx while she navigates the most dangerous parts of City 17 and dispatches alone whole squads of Combine soldiers to free her father, then her planet. Alyx is capable of holding on her own against the Combine, is athletic and knows how to wield firearms.
* ADayInTheLimelight: ''Half-Life: Alyx'', as the name suggests, is about how she and Eli founded the Resistance before the events of ''Half-Life 2''.
* ArmorIsUseless: See MadeOfIron; bizarrely enough, she can survive much more damage than other human [=NPCs=] (bar Barney and Freeman himself), even though she's not wearing any kind of armor, just a jacket and hoodie.
* BadassInDistress: [[spoiler:In the initial ''Half-Life 2'', she gets bagged by the Combine during the revolt, and almost ends up sent through a Combine portal before Mossman saves her. In ''Episode Two'', she gets skewered by a Hunter and is rendered OnlyMostlyDead until the Vorts save her.]]
* BareYourMidriff: [[DownplayedTrope If you can call what could be at most couple of centimeters of skin at most a “midriff”, then yes.]] Played straight for most of her skins in the infamous Cinematic Mod.
* BoyishShortHair: She has a short haircut, appropriate for an ActionGirl in LaResistance.
* ButNotTooBlack: Noticeably fairer-skinned than her father, commonly mistaken for a tanned Caucasian woman (even though she's half African-American, half Malaysian). This is likely a leftover from when her father was intended to be a Caucasian military man named Captain Vance, who became Eli Vance through mid-development story changes.
** Downplayed in ''Half-Life: Alyx'', as her [[https://combineoverwiki.net/images/2/21/HLA_Alyx01.jpg rebuilt 3D model]] has noticably more darker skin than her ''Half-Life 2'' model.
%%* DeadpanSnarker
* {{Deuteragonist}}: Of the ''Half-Life 2'' series.
* DisneyDeath: [[spoiler:In ''Episode Two'' she gets stabbed in the back by a Hunter, and just manages to say "Gordon... help..." before she passes out, appearing to be dead. Her condition goes from critically injured to no pulse left just before the Vortigaunts manage to save her.]]
* DuctTapeForEverything: A separated seam on the right shoulder of her jacket is covered over with strips of duct tape.
* ExpositionFairy: When she accompanies you, she gives explanations on how the Gravity Gun works, and provides brief background for areas like Ravenholm and Nova Prospekt.
* FingerlessGloves: She always wears a pair of leather gloves with the fingers cut off.
* FriendlySniper: Wields a mounted Combine sniper rifle in ''Episode Two'' to help Gordon blow away Zombies in the outskirts of Victory Mine.
* GiveGeeksAChance: She seems quite attached to Gordon. When her father Eli semi-jokingly tells her he wants grandkids while she and Gordon are both listening, leaving no doubt as to whom he envisions as their father, she laughs it off but doesn't actually appear disinclined to the idea.
* {{Handgun}}: Her main weapon throughout the ''Half-Life 2'' series is a custom made machine pistol she carries around in her jacket.
* IconicSequelCharacter: Was introduced in ''Half-Life 2'', and has arguably supplanted Freeman as the most recognizable character in the series.
* TheLancer: To Gordon for the Episodes.
* KilledMidSentence: In the ending of ''Half-Life 2'', where the Citadel reactor explodes before she even has a chance to escape, meanwhile Gordon is carried off by the G-Man. Subverted in the introduction of ''Episode One'' however, where the Vortigaunts intervene to rescue Alyx and thwart the G-Mans plans.
* MasterOfUnlocking: Her EMP tool lets her get through a lot of places Gordon would otherwise be unable to reach.
* MadeOfIron:
** It takes an ungodly amount of punishment to kill her, and unlike Freeman and Shephard, there is no in-game justification for it (the in-engine explanation for her durability is that she has insanely high [[RegeneratingHealth health regeneration]] as an AntiFrustrationFeature so the areas in which she fights alongside you don't feel like an EscortMission).
** Toned down heavily in ''Half-Life: Alyx'', where she can sustain plenty of abuse as the PlayerCharacter, but will eventually die within reasonable limits.
* MessyHair: She has a rather rough haircut. Being a member of an underground Resistance movement likely doesn't leave her much time for personal hygiene.
* MissingMom: Her mom died during the Black Mesa incident.
* MissionControl: Adopts this role occasionally (such as a couple times in ''Half-Life 2''), though she does a ''lot'' more of accompanying the hero into the field.
* MyGodWhatHaveIDone: In ''Half-Life: Alyx'', [[spoiler:the G-Man shows her Eli's death five years in the future with little context, knowing she'd impulsively do ''anything'' she could to stop it. So when he offers her the chance to do so, she takes it without a second thought, changing the future - [[DealWithTheDevil and then realizes she messed up bad]] when he talks about the consequences of such an action. Alyx doesn't take it well right before she's put into stasis as a replacement for Gordon.]]
* MyNaymeIs: Al'''y'''x.
* NerdsAreSexy: She's very knowledgeable about science and mechanics, and well... LOOK at her.
* NiceGirl: She's a serious contender for the title of "Nicest Companion In The History Of Gaming". Alyx is nothing but supportive of Gordon, commends him on pretty much every even slightly awesome feat he pulls off, protects him with her life without a second of hesitation, always asks him to be careful when the circumstances force her to send him to do something she can't do herself... At the beginning of Episode One, she's so overjoyed to see him alive she actually greets him with an epic first-person {{Glomp}}. Some time later, after Gordon single-handedly wrecks a gunship and then a Strider, she almost bubbles over with awe and names him her personal hero. It's also very apparent she really, really loves her dad and cares deeply about just about everyone else (especially Gordon, of course, whom she seems to have more than a slight crush on). She even gives a Vortigaunt a peck at one point.
* PluckyGirl: As befits her younger age, she is noticeably restless around her dad and his coworkers, relieved when he gives her an opportunity to get out of the bunker and do something. It's not that she dislikes them, it's just...the generational gap.
* PreAsskickingOneLiner: "Hah! No you don't!" ''[beats the shit out of four armed Metrocops in about five seconds]''
* PrecisionFStrike: She responds to [[spoiler:Mossman's attempts to justify her betrayal]] with "[[ShutUpHannibal Enough of your bullshit!]]"
* PromotedToPlayable: ''The'' main star of her own eponymous title after over a decade.
* RescueIntroduction: She and Gordon meet when she saves him from a group of Metrocops.
-->[[PreAsskickingOneLiner "Hah! No you don't!"]]
* SecondaryFire: Her custom machine pistol is capable of semi-auto, burst, and automatic fire.
* ShipTease: With Gordon. Loads of it by various characters.
* SpitefulSpit:
-->'''Breen:''' ''[to Eli]'' Will you let your stubborn short-sightedness doom the entire species, or... ''(touching Alyx's face)''... will you give your child the chance her mother never had?\\
(''She spits in his face.'')\\
'''Alyx:''' How dare you even ''mention'' her!
* StoneWall: In gameplay terms. She's pretty much functionally invincible, but her only permanent weapon is her trusty machine pistol--BottomlessMagazines or no, it doesn't come close to Gordon's sheer armament.
* TraumaCongaLine: Where to start? For the first years of her life, she lives in the dormitories of Black Mesa, a [[NoOSHACompliance dangerous and accident-prone]] research facility. Then, her mother is killed during the Black Mesa Incident. She only survives because [[spoiler:the G-Man]] saves her life, putting her in his debt unknowingly. Fast forward to when she meets Gordon Freeman, leading to events in which her father is captured by the Combine. In the end, when the [[spoiler:dark matter reactor explodes, killing Breen]], she only [[spoiler:survives because the Vortigaunts teleport her out of the wreckage]]. In the beginning of ''Episode Two'', she is [[spoiler:stabbed twice by the long blades of a Hunter and survives, once again, because of the Vortigaunts.]] Finally, after [[spoiler:Eli, Magnusson, and Kleiner launch the rocket and Gordon and Alyx are about to get into a helicopter to save their friend Mossman, a pair of Advisors smash through the building and kill Eli right in front of her.]]
** In ''Half-Life: Alyx'', [[spoiler:she’s given the chance to save Eli and succeeds, but is “employed” by the G-Man soon after.]]
* UnkemptBeauty: She's famous for her MessyHair.
* TheWorfEffect: [[spoiler:Suffers a DisneyDeath at the hands of a Hunter in Episode 2 and she would’ve become Antilon food if a Vortigaunt didn’t save her.]]
* WhyDidItHaveToBeSnakes: She seems to have developed a slight fear of [[spoiler:Hunters]] after [[spoiler:her near death experience]] in ''Episode 2''.
* WrenchWench: She created D0g, after all.
[[/folder]]

!!Supporting Characters
[[folder:Dr. Eli Vance]]
[[quoteright:206:https://static.tvtropes.org/pmwiki/pub/images/eliv_6086.png]]
-> Voice Actor: Creator/RobertGuillaume (''Half-Life 2'', Episodes ''One'' and ''Two''), Creator/JamesMosesBlack (''Half-Life: Alyx'') (English)[[note]]'''Other Languages''':Diran Megreblyan (''Half-Life 2''), Alexander Gruzdev (Episodes ''One'' and ''Two'') (Russian)[[/note]]
A major character in ''Half-Life 2'', Eli Vance is one of the survivors of the Resonance Cascade incident, a lead member of the Resistance, and Alyx's father. Also known to be a Harvard graduate.
----
* AscendedExtra: Remember that scientist in ''Half-Life 1'' that sent you up for help after the Resonance Cascade and opened the door for you? That's Eli. Made more obvious in ''VideoGame/BlackMesa,'' the Source FanRemake that was [[invoked]][[OfficialFanSubmittedContent endorsed by Valve.]]
* ArtificialLimbs: Eli apparently lost his left leg during an [[NoodleIncident incident involving a Bullsquid.]] He has a makeshift prosthetic now.
* BackFromTheDead: [[spoiler:In ''Alyx'', through a combination of a DealWithTheDevil and RealityWarping by the G-Man, Alyx saves his life from the Advisor that kills him at the end of ''Episode Two''.]]
%%* DeadpanSnarker
* DistressedDude: One of the major goals driving the plot is Alyx's quest to rescue her father, twice. This isn't exactly a new thing, as ''Half Life: Alyx'' shows.
* ISeeThemToo: So far, he has been one of the few characters who has acknowledged the G-Man, a.k.a. "our mutual friend's" existence to Gordon.
* IWantGrandkids: Hey, you can't blame him, considering the Combine's anti-reproduction suppression field in the past ''twenty'' years.
* LikeASonToMe: [[spoiler:Shortly before he's killed by an Advisor]], he tells Gordon that he couldn't be more proud of him if Gordon were his own son.
* MyGodWhatHaveIDone: The personal cutscene between Gordon and him in ''Episode Two'' pretty much made him admit [[spoiler:he was doing oversight for the test leading up to the Resonance Cascade.]]
-->''"When he came in, I knew I should have aborted that damn test. [[ForWantOfANail But I didn't]]. The whole world went to hell that day."''
* RebelLeader: Is the de facto leader of the Resistance, seeing as Black Mesa's remnants became the foundation of the movement.
* RoaringRampageOfRevenge: [[spoiler:Swears such on the G-Man after the end of ''Alyx'' once brought back to life and realizes he abducted his daughter as the cost.]]
--> '''Eli:''' [[spoiler:She's gone, Gordon... she's gone... [[SuddenlyShouting SON OF A BITCH AND HIS UNFORESEEN CONSEQUENCES!]] I knew it! When I get my hands on him, I'm gonna... ''I'm gonna kill him''.]]
* SacrificialLion: [[spoiler:At the end of ''Episode Two'', right before Gordon and Alyx were to board the helicopter to find the Borealis, he is killed by a Combine Advisor by having his brain sucked out right in front of Gordon and Alyx.]]
* ShipperOnDeck: He's obviously quite fond of the idea of Gordon and Alyx hooking up.
* SoProudOfYou: Says this to both Alyx and Gordon [[spoiler:mere minutes before he's gruesomely killed by an Advisor. It's heavily implied he knew his end was coming and took the chance to secretly say farewell.]]
[[/folder]]

[[folder:Dr. Rosenberg]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/rosenberg_bust_bs.jpg]]
%%[[caption-width-right:350:]]

-->"Let those fools try and fight a battle they can't win! I just want to [[ScrewThisImOuttaHere get out of here!]]"
-->-- Rosenberg making his intentions very clear.

-> '''Voice Actor''': John St. John
A scientist partly responsible for the Black Mesa incident and the military storming the facility, he attempts to flee the facility unlike his colleagues [[ActionGirl Gina and Colette]]. While hatching a escape plan, he gets [[DudeInDistress captured]] by HECU soldiers and is rescued by Barney Calhoun, who helps him and a few other scientists escape from the facility.
----
* AmbiguouslyJewish: Rosenberg is a Jewish name of German origin. [[JustifiedTrope]] as his name and likeness are likely inspired by the electrical engineer Julius Rosenberg.
* CassandraTruth: He's a bit concerned with the Anti-Mass Spectrometer being ran at dangerous levels, especially after his colleague Harold warns him of the risks. Dr. Richard Keller dismisses these concerns and states that the administrator (Breen)'s instructions are clear. When the Resonance Cascade happens, he suffers a bit of HeroicBSOD and holds himself the most responsible.
* DirtyCoward: Downplayed. He hatches a plan to escape Black Mesa along with his fellow scientists. He is however willing to involve other Black Mesa personnel such as [[OddlyOvertrainedSecurity Barney Calhoun]] in the plan, thus saving their lives.
* EarlyBirdCameo: He is one of the many scientists overseeing Barney Calhoun during his training. Could also count as CaptainObviousReveal since he has a unique model and the other scientists share the same models.
* LastNameBasis: His colleagues only ever call him "Rosenberg" or "Doctor Rosenberg".
* ScrewThisImOuttaHere: Pulls this during the incident, thinking that [[SilentProtagonist Gordon Freeman]] and the Lambda Team can handle it.
* SmallRoleBigImpact: Because of him, Barney Calhoun managed to escape Black Mesa and return for the sequel.
* SuddenSequelDeathSyndrome: Probably. See What Happened to the Mouse? down below.
* SurvivorGuilt: He holds himself the most responsible for the incident and the military storming the facility. He attempts to redeem himself by saving other Black Mesa staff.
* WhatHappenedToTheMouse: Just like Gina and Colette, he is nowhere to be seen in ''Half-Life 2'' despite Barney Calhoun appearing alive and well. The other survivors of the Black Mesa incident including Barney don't even mention him.
[[/folder]]

[[folder:[=D0G=]]]
[[quoteright:299:https://static.tvtropes.org/pmwiki/pub/images/hla_dog.png]]
A walking junkpile that moves like a robotic gorilla, but has an effective mindset of a dog, hence his name. Fiercely loyal to and protective of Alyx, and her friends by extension.
----
* BadassAdorable: Has quite the endearing attitude when he's happy, but when he's on the warpath, he'll smash the utter shit out of anything that isn't a [[spoiler:Strider, where the ''only'' difference is that he'll take it apart with his bare hands instead.]]
* BigFriendlyDog: You play catch with him as part of Alyx's training regime for the gravity gun.
* TheBigGuy: He's the size and shape of a ''very'' big gorilla.
* CurbStompBattle: Him versus any Combine forces short of a Strider. His favored method is to pick up ground vehicles and throw them at the enemy. And when he stays behind to allow Gordon to go to the Citadel, he thrashes the pursuing Combine soldiers so badly that they are flung around like ragdolls before jumping onto a Dropship.
* DavidVersusGoliath: [[spoiler:Him versus a Strider.]]
* LightningBruiser: He's more than capable of wrecking pretty much anything in his path. At the same time he's fast enough to keep up with a car going flat-out. When you race him to White Forest in ''Episode Two'' and don't make liberal use of your car's booster, chances are he'll be waiting for you at the gate when you finally get there.
* MyNaymeIs: [=D0G=] (with a zero) is written on his body shell. The in-game subtitles spell it "Dog" (with a letter o).
* NiceGuy: Just as loyal and friendly as his namesake.
* NoSell: Because he isn't organic, he is immune to the Advisors' psychic attacks.
* RobotBuddy: He's loyal just like a normal dog, but is made from scraps.
* RobotDog: Fits behavior-wise, if not in appearance. [[https://combineoverwiki.net/images/0/05/HLA_DogPictures04.jpg A photo]] in ''VideoGame/HalfLifeAlyx'' shows the original model built by Eli looked more dog-like before Alyx began upgrading him.
* WhatAPieceOfJunk: Consider him a junky old robot at your own peril if you're a Combine. He ''will'' thrash you.
[[/folder]]

[[folder:Dr. Isaac Kleiner]]
[[quoteright:191:https://static.tvtropes.org/pmwiki/pub/images/isaac_kleiner_3882.png]]
->Voice Actor: Harry S. Robins (English)[[note]]'''Other Languages''':Dmitry Polonsky (Russian)[[/note]]
->''"That's right, Barney. [[TitleDrop This is a red letter day]]. We'll inaugurate the new teleport with a double transmission!"''
A major character in ''Half-Life 2'', Isaac was the man who recommended Gordon Freeman to Black Mesa Research Facility's Civilian Recruitment Division. Also a survivor of the Resonance Cascade incident at Black Mesa. [[RuleOfThree Was also]] Gordon's theoretical physics teacher at the Massachusetts Institute of Technology.
----
* AbsentMindedProfessor: Fits the stereotype perfectly, though he's not quite as absent-minded as some. In fact, more of the problems that come from interacting with him tend to be Lamarr's fault, rather than his.
* AdmiringTheAbomination: He's implied to be the scientist who finds headcrabs fascinating in the first game, leading to him ''keeping one as a pet'' in the second.
* AmbiguouslyJewish: Has a Hebrew given name (though admittedly, Hebrew given names are nothing of an oddity in Europe) and a German surname, and named his pet headcrab after a Jewish actress.
* AscendedExtra: Like Barney, he's a stock scientist from the original game turned into a main character in the sequel.
* BaldOfAwesome: He's almost completely bald, but still a highly capable scientist and a fairly entertaining fellow.
* CrouchingMoronHiddenBadass: The badass is hidden pretty deep down, but, he did manage to escape from Black Mesa alive and stay alive for years afterwards as a rebel. Plus, he somehow managed to catch a headcrab alive and surgically remove its zombifying fangs without getting turned into a zombie himself; give the man some credit for that.
** Then there's the part of the game where Gordon and Alyx teleport from Nova Prospekt right into Kleiner's lab when he isn't looking. His first reaction to the strange noises is to slowly creep through the door with a [[ShotgunsAreJustBetter shotgun]], presumably expecting to blow away Combine intruders from his lab.
*** If you look around, you can find the wreckage of a Manhack, most definitely destroyed by Kleiner himself.
* FluffyTamer: He keeps a "de-beaked" headcrab as a pet. Her name is [[Creator/HedyLamarr Lamarr]].
* NiceJobBreakingItHero: It really wouldn't be inaccurate to lay the entire mess of the second game and its expansion packs on him. It was Lamarr who disrupted the teleporter, causing Breen to become aware of Freeman's restoration, which resulted in the Transhuman Forces being rallied, which led to... well, all of the death and destruction the player sees sweep before them over the course of the game. All because he had to keep a frigging untameable brain-sucking alien monster as a pet.
* NoodleIncident: It has something to do with the cat and the teleporter in his lab. Barney mentions the cat twice.
* PerformanceAnxiety: Downplayed, but present. In ''Episode One'', he's put in charge of delivering evacuation broadcasts and valuable exposition on the state of the war the Resistance is in, and is obviously nervous through his tone and breathing when he begins. He gradually begins to hit his stride to the point of delivering an inspiring speech to give hope to the rebels.
* PetsHomageName: His "de-beaked" headcrab is named after Creator/HedyLamarr.[[note]][[Film/BlazingSaddles That's Hedley!]][[/note]] It's both a bad StealthPun and a ShoutOut to a classic actress--one who helped pioneer early wi-fi and cordless technologies.
* RefugeInAudacity: Setting up a resistance research lab in the Combine's capitol city certainly took some ''chutzpah''.
** No less, a research lab located [[RightUnderTheirNoses right down the block from a major train station crawling with metrocops.]]
* TheSmartGuy: He creates a short-ranged teleportation system that allows for transportation on the same planet. Something that the Combine haven't figured out themselves yet.
* VoiceOfTheResistance: Becomes one temporarily in Episode 1 when the Resistance hijacks Breen public broadcast system. It's mostly to give instructions on how to evacuate City 17, but he does take some time to give an inspirational speech about finally taking back the planet which is pretty impressive for someone who admits he's not very good at public speaking. [[MomentKiller Then he reminds everyone that the suppression field is down and now would be a good time to fuck.]]
[[/folder]]

[[folder:Lamarr]]
[[quoteright:300:https://static.tvtropes.org/pmwiki/pub/images/lamarr_2.jpg]]

Dr. Kleiner's de-beaked pet headcrab.
----
* AllAnimalsAreDogs: Downplayed; while Kleiner has managed to domesticate it to some extent and "debeaked" its ability to control a host, Lamarr still retains much of the predatory behavior of a typical Headcrab and Kleiner doesn't seem to have much control over the creature as it attacks Barney and aggressively hisses to both him and Kleiner before escaping to the airducts during its first appearance. That being said, it appears to pant like a dog when resting from hopping around, and Kleiner can hold and pet it without it struggling.
* ForWantOfANail: The situation was already bad for Gordon when he got off the train, but Lamarr actively made it worse. When he was about to be teleported to Black Mesa East, Lamarr jumps into the teleporter too and causes it to go haywire. Gordon teleports into Dr. Breens office and surprises him, leading to City 17 being put on high alert, which leads to the entire Civil Protection force going after him, and later the formal Combine military, and a broken teleporter so he can't even get to Black Mesa East in time. All because Kleiner didn't decide to leave Lamarr caged up for the experiment.
* FluffyTheTerrible: A formerly dangerous PuppeteerParasite named for a famous Golden Age actress.
* HurlItIntoTheSun: [[spoiler:Last seen in the nosecone of a rocket launched into the Combine super-portal. If it's not dead it's in another universe.]]
* NamedAfterSomebodyFamous: Named after Creator/HedyLamarr.
* PunnyName: A headcrab named after Creator/HedyLamarr.
* SmallRoleBigImpact: Basically a good portion of the game wouldn't happen without its interference.
* TeamPet: For The Resistance, though most members don't seem to like it all that much.
-->''We're all starving, and Kleiner's Headcrab is probably eating grade-A head!''
* TrademarkFavoriteFood: Watermelons, if a sticky note found in Kleiner's lab is any indication. Must be a good substitute for heads.
* UnwittingInstigatorOfDoom: Unwitting because it's a dumb animal, but thanks to Lamarr climbing into the teleporter, Gordon gets teleported into Breen's office and alerts the Combine to his presence.
[[/folder]]

[[folder:Dr. Judith Mossman]]
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/250px-judith_mossman_7678.jpg]]

-> Voice Actor: Creator/MichelleForbes (English)[[note]]'''Other Languages''':Rita Weisman (''Half-Life 2''), Larisa Grebenshchikova (''Episode One'') (Russian)[[/note]]
->''"The Zero Point Energy Field Manipulator is not a toy, Alyx!"''
The other scientist at Black Mesa East, and is somewhat distrustful of Alyx. Was last seen with Resistance members tracking down the ''Borealis'', and got ambushed from the Combine before she could finish her message. She is still alive, whereabouts unknown. Her message was found by Gordon and Alyx, who were pursued by the Combine while delivering it to the scientists in White Forest Base.
----
* BitchInSheepsClothing: Comes off as friendly and professional in her initial appearance, even if she doesn't get along with Alyx, [[spoiler:but she's secretly working for the Combine.]]
* FaceHeelRevolvingDoor: It certainly seems that way, considering how often she appears to switch sides.
* InkSuitActor: Looks quite a lot like Michelle Forbes.
* JerkWithAHeartOfGold: [[spoiler:Works for and against the Resistance so she can get close enough to Breen to kill him.]]
* MeaningfulName: Judith's name sounds a lot like Judas. Consider that Gordon Freeman is hailed as a MessianicArchetype by the Vortigaunts, and it becomes clear that she cannot be trusted.
* TheMole: [[spoiler:Initially, but pulls a HeelFaceTurn]] later on. It's not clear if she's an example of [[spoiler:a FakeDefector]] or [[spoiler:WelcomeBackTraitor]].
%%* MyGodWhatHaveIDone
[[/folder]]

[[folder:Dr. Arne Magnusson]]
-> Voice Actor: John Aylward (English)[[note]]'''Other Languages''':Andrey Yaroslavtsev (Russian)[[/note]]
[[quoteright:218:https://static.tvtropes.org/pmwiki/pub/images/arne_magnusson_4769.png]]
->''"Oh, and Freeman! If you pull this off, I might just forgive you for that [[BaitAndSwitch debacle at Black Mesa]]. You know the one I mean – [[BrickJoke involving a certain microwave casserole]]."''
The manager of White Forest Base. Has a very distrustful relationship with Isaac Kleiner (well, they fought between each other for grant money). Later revealed to be the owner of a certain microwave casserole in the lounge of the Sector C Personnel Facilities in Black Mesa.
----
* BrickJoke: Remember the microwave casserole you had the option to blow up in the beginning of the first game? According to canon, that just so happened to be Arne's casserole, and Gordon did in fact blow it up, something Arne still hasn't forgiven.
* GoodIsNotNice: Well, he's definitely not nice.
* ItsAllAboutMe: Magnusson is an incredibly egocentric asshole. Listening to him alone, it's very easy to get the impression that he does ''everything'' there is to do while everyone else exists solely to annoy him or hinder his great accomplishments. During the final sequence of ''Episode Two'' he explicitly takes full credit for the success of the entire operation (including the brutal defence of White Forest against ''a dozen friggin' Striders plus their Hunter escorts''), completely ignoring the fact that he would've gotten nowhere without the invaluable support of scores of brave people, the player character among them, naturally.
* {{Jerkass}}: Specifically created to be this to contrast with Eli and Isaac.
* MilesGloriosus: For all his pompousness, he can't even be bothered to secure his own base, dismissing any alarms as "crows". And his anti-strider bombs don't even have any propelling or detonating mechanisms, forcing Gordon to launch and detonate them manually.
* {{Narcissist}}: To the point where he names anti-strider bombs after himself.
* PetTheDog: He is grateful for Gordon's part in the rocket launch, although he really seems to have difficulty expressing it (and even then he manages to mostly praise himself).
* RememberTheNewGuy: He just appears during ''Episode Two''. Sure, it's implied he hadn't seen Gordon in a long time, but it still appears as though they know each other.
* SmallNameBigEgo: Given that his name is never even mentioned until the action shifts to White Forest, it is implied that he has no prominence outside of White Forest whatsoever.
* StockForeignName: Arne Magnusson is a typical Scandinavian name.
[[/folder]]

[[folder:Father Grigori]]
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/250px-fathergrigori_1599.jpg]]
-> Voice Actor: Jim French (English)[[note]]'''Other Languages''':Vyacheslav Shumov (Russian)[[/note]]
->''"I am Father Grigori! [[DeadpanSnarker You have already met my congregation]]."''
Very little is known about him other than that he's a [[AmbiguouslyChristian Russian Orthodox-like]] preacher of questionable sanity who has taken it upon himself to clear his "[[ZombieApocalypse flock]]" from Ravenholm.
----
* AmbiguouslyChristian: His denomination isn't fully addressed, but heavily implied to be Orthodox Christian in the Ravenholm chapter.
* BadassNormal: All he has is his old fashioned rifle and plenty of makeshift booby-traps to fend off the zombie hordes, and he's avoided getting caught by any Headcrabs and getting mauled by zombies ever since the initial Combine attack.
* BadassBaritone: He has a deep, gravelly voice, courtesy of the late Jim French.
* BadassPreacher: While the preacher part may be questionable as his backstory is never expanded on, he is still a badass for being able to survive and remain in the zombie and headcrab-infested Ravenholm.
* BaldOfAwesome: [[BadassBeard Barring his beard]], Grigori lacks a strand of hair on his scalp and he fends off Headcrabs and Headcrab zombies of all kinds with his massive arsenal and clever traps.
* BattleAmongstTheFlames: The final time he's seen, [[HeroicSacrifice he bids farewell and safety to Gordon and rushes into an erupting fire to hold off the incoming zombie horde]], [[LaughingMad laughing maniacally all the while.]]
* CrazySurvivalist: Grigori's the ''nice'' kind.
* CreepyGood: Living through [[ZombieApocalypse what]] [[PuppeteerParasite happened]] [[FateWorseThanDeath in]] [[GhostTown Ravenholm]] did a number on his mental health, but he's entirely helpful to Gordon. It's implied he also tried his best to help others.
* EvilLaugh: His laugh is pretty evil sounding, even though he's helping you.
* GoodSamaritan: Grigori is the only NPC in the entire game to help Gordon Freeman without recognizing who he is. He just thinks it's the right thing to do.
* GoodShepherd:
** While there are few people left in Ravenholm for him to help, he gives Gordon a shotgun, some supplies, and has built several traps that Gordon uses on the zombies. It is implied that Grigori has done the same for other rebels.
** It's implied that, with [[ZombieApocalypse the state that the combine has left his flock in]], he sees his role as the one responsible for their "salvation" as having morphed into a duty to give every last one of them a MercyKill. For what it's worth, he can still be heard giving conventional sermons to the zombies even while he blasts them to pieces.
* HeroicSacrifice: He willingly stays behind to slow the zombie hordes down and allow Gordon to escape. Whether he actually dies is never made clear. See below under Uncertain Doom.
* InsaneEqualsViolent: He went mad after what happened to Ravenholm (though to be fair everyone would have gone insane) and he's ''technically'' violent since he lives in a CrapsackWorld surrounded by zombies (if there were no zombies, he wouldn't be violent, so it's not a result of his insanity), but he's 100% benevolent and helpful towards Gordon.
* LargeHam: He is a mad priest who recites all his psalms on rooftops in a very theatrical manner, often followed by a [[LaughingMad mad laughter]].
* MeaningfulName: "Grigori" is a term in Biblical apocrypha for a group of angels tasked with watching over humanity as well as the name of [[UsefulNotes/GrigoriRasputin another famous Russian preacher]] who was supposedly [[RasputinianDeath very hard to kill]].
* MercyKill: What he does to the Headcrab Zombies, and is more than likely why he hasn't left town yet. He's [[AndIMustScream perfectly]] [[FateWorseThanDeath justified]].
* NiceGuy: Extremely helpful to Gordon Freeman, he's ready to risk his life for him.
* NiceShoes: Just about every [=NPC=] in the game is wearing black or brown boots. This guy is wearing red sneakers.
* SanitySlippage: He's obviously insane, although it's implied that he was driven insane by the whole headcrab infestation in Ravenholm. That being said his insanity doesn't make him dangerous to others, in fact he's actually an extremely brave and decent fellow.
* SoleSurvivor: The only individual known to still be alive and well after the population of Ravenholm was utterly wiped out in the headcrab infestation.
* UncertainDoom: The devs have stated Grigori will never appear on-screen again, so whether or not he's still alive is a mystery.
* WeaponOfChoice: A .357 caliber lever action rifle called "[[ICallItVera Annabelle]]".
[[/folder]]

[[folder:Colonel Odessa Cubbage]]
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/250px-odessa_cubbage_bust_nlo_7629.jpg]]
-> Voice Actor: John Patrick Lowrie (English)[[note]]'''Other Languages''':Boris Isarov (Russian)[[/note]]
->''"Ah! Gordon Freeman! I couldn't have asked for a finer volunteer!"''
A somewhat suspicious and supposedly British Resistance colonel, leading the New Little Odessa base along the coast. He only appears briefly in the 7th chapter of ''Half-Life 2'', granting Gordon a rocket launcher.
----
* CallBack: After playing out his minor role in ''Half-Life 2'', he disappears from the plot, and there is no mention of him again. Then, late in ''Episode One'', three independent mentions suddenly turns up concerning him, first Alyx sarcastically claiming he is her father, then two rebels coming to the conclusion that he is an idiot, and finally a rebel who reveals that he had taken the credit for Gordon's work, and who turns out to be an admirer of him.
* CowerPower: When the base he has responsibility to lead comes under an attack threatening its very existence, no less, Cubbage sends Freeman to dispatch the gunship, while he safely hides to send a warning to another base, that mysteriously never reaches its destination despite taking so long.
* DirtyCoward: Once a gunship invades his base, he chooses to hide inside the basement throughout the whole fight, despite [[BlatantLies promising]] to "lend a hand".
* MilesGloriosus: While there is no explicit mentions of his great military exploits, he does by no means seem like someone deserving a colonel title.
** Better yet, a passing comment in ''Episode One'' reveals that he took the credit for shooting down aforementioned gunship.
* MysteriousPast: The Prima Guide to ''Half-Life 2'' states that virtually nothing is known of Cubbage's past, his name may even be taken from the outpost, the only thing sure is his cowardice.
** If Gordon uses the Combine binoculars overlooking New Little Odessa, he can be seen talking to the G-Man.
* RebelLeader: Although how significant he is doubtable.
* SmallNameBigEgo: It is staggeringly clear that he believes himself to be one of the great heroes of LaResistance, although he appears to be the only one with this view, apart from one rebel in ''Episode One'' speaking somewhat highly of him.
[[/folder]]

[[folder:Griggs and Sheckley]]
[[quoteright:200:https://static.tvtropes.org/pmwiki/pub/images/griggs_and_sheckley_9725.jpg]]
-> Voice Actor: John Patrick Lowrie (Griggs); Creator/AdamBaldwin (Sheckley) (English)[[note]]'''Other Languages''':Andrey Yaroslavtsev (Griggs); Maxim Pinsker (Sheckley) (Russian)[[/note]]
->''Griggs:"[[OhCrap The Vort says as long as we don't step on their Grubs, they shouldn't hear us this far from the nest...]]"''
->''Sheckley:"Yeah, well, that's a theory I would rather not test."''
A pair of resistance members in an underground base, they help Freeman defend the base against an army of Antlions to protect the Vortigaunts while they heal Alyx. Griggs the field medic , and Sheckley is the rebel soldier.
----
* DeadpanSnarker: Sheckley doesn't even try to humor Griggs at all.
--> '''Sheckley''': Hey, you see a bug on me, how about you try to get it off next time?
--> '''Griggs''': I didn't see it!
--> '''Sheckley''': Yeah, they're only like [[BigCreepyCrawlies five feet tall!]]

--> '''Griggs (After an Antlion attack)''': I got... ten!
--> '''Sheckley''': Yeah well we all got ten, there's hundreds of them!
* ProperlyParanoid: When Freeman arrives, Griggs thinks it's a bunch of Antlions. Turns out they're not that far behind.
* RedOniBlueOni: Griggs is the red, Sheckley is the blue, with Griggs being a jittery, paranoid mess who loses his cool while Sheckley is a no-nonsense and reasonable fighter who remains calm even when being swarmed from all angles.
* HoldTheLine: Gordon has to help them hold off incoming Antlion swarms until their Vortigaunt reinforcements can arrive, with the help of jury rigged sentry guns, landmines and motion sensors.
* TemptingFate: After Gordon has spent a ''long'' time running around the Antlion nests, shooting workers, disrupting the hive and likely stomping on grubs all the way through, Griggs has this to say when he arrives to their safe haven within that very same nest.
-->'''Griggs:''' The Vort says as long as we don't step on their grubs, they shouldn't hear us this far from the nest.\\
'''Sheckley:''' Yeah well, that's a theory I'd rather not test.
* ThoseTwoGuys: [[invoked]][[WhatCouldHaveBeen They were originally meant to serve as]] [[ExpositionFairy Exposition]] RedShirts, but they were developed into actual characters who survive the battle.
[[/folder]]

[[folder:Russell]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/russell_2.jpg]]
-> Voice Actor: Rhys Darby (''Half-Life: Alyx'')
->''"I'm with you every step of the way."''
A more older gentleman and one of Alyx's allies in ''Half-Life: Alyx''. He has a secret lab inside of his apartment, where he invented the "Russells", a pair of gravity-manipulating gloves as well as a pistol which serves as Alyx's main tools throughout the game.
----
* BrutalHonesty: [[InnocentlyInsensitive Not on purpose mind you]], but he has a habit of being a bit blunt.
--> '''Russell''': Now, pretty soon they're going to realize that your dad is not going to talk, and when that happens he's off to have his brain sucked out.
--> '''Alyx''': Russell.\\
'''Russell''': Potentially. Maybe not, though. I mean he could- they could just drill into his-
--> '''Alyx''': Stop.
* CoolOldGuy: Russell may be aged and have white hair, but he still managed to hide a laboratory inside his own apartment ''and'' create a pair of gravity-manipulating gloves.
* HomemadeInventions: He invented the gravity gloves inside his apartment.
* ItBeganWithATwistOfFate: He knew Eli from when he interviewed at a job for Black Mesa. They liked him, but declined to hire him, encouraging him to reapply next year. Since the Resonance Cascade happened less than a year after that, he considers himself to have gotten out lucky.
* MissionControl: He serves as one for the duration of ''Alyx''.
* UnwittingInstigatorOfDoom: Russell hacks the Combine construction cameras mostly to be cheeky at the beginning of the game, only to shortly begin to wonder just what he's seeing; something he later notes to have merely been blurry pictures of a strange structure that turns out to be the Vault. This alone triggers the Combine to react ''violently'', capturing Eli and setting ''Half-Life: Alyx'' into motion.
* WhatHappenedToTheMouse: Russell is never seen or mentioned again after Alyx enters the Vault.
[[/folder]]

[[folder:The G-Man]]
[[quoteright:300:https://static.tvtropes.org/pmwiki/pub/images/gman_3.png]]
-> Voice Actor: Mike Shapiro (English)[[note]]'''Other Languages''':Oleg Fedorov (''Half-Life 2''), Nikita Prozorovsky (''Half-Life 2: Episode One'', ''Half-Life 2: Episode Two'') (Russian)[[/note]]
->''"Rise and shine, Mr. Freeman. Rise and shine. Not that I wish to imply you have been sleeping on the job. No one is more deserving of a rest. And all the effort in the world would have gone to waste until...well, let's just say your hour has come again. The right man in the wrong place can make all the difference in the world. So, wake up, Mr. Freeman. Wake up and smell the ashes."''
An eldritch and enigmatic character, looking like a blend between a government worker and a businessman, who apparently possess a degree of control over space and time. All we know is that he's been observing the events of the entire ''Half-Life'' series. And that he is possibly not entirely human. He apparently answers to some higher authority which he simply refers to as his "employers". He has, however, on a couple of occasions hinted that he does not necessarily obey these "employers".
----
* AccentUponTheWrongSyllable: Although sometimes he accents the right syllable just with ''far'' too much emphasis.
* ActionSurvivor: Implied to be the case in one of the few allusions to his history:
-->'''G-Man''': I admit I have a fascination with those who adapt and survive against all odds. They rather remind me of myself.
* AffablyEvil: We actually don't know how much "evil" he is. But if he is, he's pretty damn proper about it.
* AmbiguouslyEvil: On one hand, his chessmaster antics, creepy dialogue, and mysterious powers make him easy to see as a villain of some sort. Plus, the Vortigaunts seem to oppose him and Eli suggests [[spoiler:he's the one who gave Black Mesa the crystal that caused the resonance cascade in the first ''Half-Life'']]. On the other hand, we know absolutely nothing about who he actually is and what his motivations are, and he ''seems'' to oppose the Combine, who definitely ''are'' villains, and he has saved Freeman and Shephard's lives on several occasions.
* AmbiguouslyHuman: He obviously isn't, but we don't know ''what'' he actually is. Presumably he just took AFormYouAreComfortableWith.
* AnimalMotifs: Sort of. Half Life: Alyx seems to give him a virus motif, likely playing into his modus operandi of subverting worlds from the inside.
* BadassInDistress: [[spoiler:At some point prior to ''Half-Life: Alyx'', the Combine actually managed to capture and ''imprison'' him. How they managed to do so is never explained. Though one should consider the possibility that [[PlayAlongPrisoner he allowed himself to be captured]], in order to trick Alyx into making the deal which effectively replaces Gordon with her.]]
* BigBad: He's definitely the big...something. However, there's just as much to suggest that he's this (his employers are unknown; the Vortigaunts don't support him; and as noted above, Eli suggests that [[spoiler:he's the one from whom Black Mesa got the crystal that caused the Resonance cascade, and by extension, the events of the entire series]]; and [[spoiler:claiming Alyx as his new agent, stealing her away from her father and friends while throwing Freeman aside]]) as there is to suggest he's the BigGood.
* BigGood: He's definitely the big...something. However, there's just as much to suggest that he's this (saving Freeman and Shepard from their doom; ''seems'' to oppose the definite villains, the Combine; saving [[spoiler:Alyx Vance]] despite his employers objecting; and [[spoiler:letting Alyx Vance save her father from the Combine]]) as there is to suggest he's the BigBad.
* BitchInSheepsClothing: While he remains a source of ambiguity and it's hard to tell his loyalties, [[spoiler:at the end of ''Alyx'', he does at least show a shade of his true colors by cruelly abducting Alyx and abandoning Gordon to fend for himself after the end of ''Episode 2'']].
* BlueAndOrangeMorality: For whom does he play? No one knows but him. [[spoiler:Given his actions in ''Alyx'', it's very likely that he's playing both sides of the war for his and his employers' benefit.]]
* TheChessmaster: He's either this, or the world champion of XanatosSpeedChess. Best exemplified by [[spoiler:the ending of ''Alyx'']].
* ChildrenAreAWaste: [[DefiedTrope The G-Man seems to disagree]], as he saved [[spoiler:Alyx Vance]] despite objections from his employers, presumably because he anticipated [[spoiler:the role she'd play in the future]]. They didn't want him to, because "she was a mere child, and of no practical use to anyone." Well... how about now?
-->'''G-Man''': When I ''-plucked-'' her from Black Mesa... I acted in the face of objections that she was a mere child and of no practical use to anyone. I have learned to ignore such ''-naysayers-'' when... ''quelling''... them, hm, was out of the question.
* ConsummateLiar: If the Nihilanth is to be trusted (which is a dubious condition, to be sure).
-->'''Nihilanth''': '''''Deceive you... he will deceive you...'''''
* CreepyBlueEyes: Look at those eyes. What the hell is up with those eyes?
* CreepyMonotone: He rarely shows emotion.
* CreepyShadowedUndereyes: Which only serve to highlight how ''odd'' the man looks.
* DeadpanSnarker: He has some moments of very dry sarcasm.
-->'''G-Man''': The biggest embarrassment has been Black Mesa, but I think that's finally taken care of itself...''[Black Mesa explodes in the background.]'' Quite so.
* DealWithTheDevil: [[spoiler:Invokes this on Alyx at the end of her game after she rescues him from the Combine prison, allowing her to save Eli Vance's life at the end of Episode Two—at the cost of being hired herself like Gordon before her, [[RetGone removing her from the timeline]].]]
* DissonantSerenity: Always remains cool and businesslike no matter what chaos is occurring around him.
* TheDreaded: [[spoiler:The Combine see Gordon as little more than a nuisance in the grand scope of things, but the G-Man apparently '''terrifies''' them so much that they built a vault ship designed to specifically contain him and only him in a position outside space-time and would go to ''any'' lengths to prevent anyone of knowing about him and his containment, [[HeKnowsTooMuch even executing passerbys and any unauthorized personnel for even passing a glance at the ship's exterior]].]]
* EarlyInstallmentCharacterDesignDifference: His general character design, specifically his face, changes from game to game.
** ''Half-Life'' and its expansions didn't give him any official character art, so all players could go off of was his primitive, low-poly model. Gearbox would later give him a higher-poly model with the expansions. Here, his eyebrows are noticeably thicker than in later iterations.
** ''Half-Life 2'' gave him a proper high-poly design (for 2004), complete with bright-green eyes and a streamlined sunken-in face. Here, he is perpetually wall-eyed and doesn't appear to emote very often, if at all.
** ''Half-Life 2: Episode 1'' made his green eyes slightly darker, his eyes properly in-line, and made him emote more often. ''Episode 2'' added more detail to his face and changed his eyes to be glowing white.
** ''Alyx'' is his most realistic iteration to-date. Wrinkles and aged skin were added to make him look more like a skinny middle-aged businessman and he emotes at almost-LargeHam levels. His eyes returned to being green again, but much darker, and he now has a noticeable lazy eye.
* GracefulLoser: Not ''necessarily'' a villain, but when the Vortigaunts foil some plan he has for Gordon, he is annoyed but doesn't retaliate; he simply waits for another opportunity to make contact, and does not seem to hold any kind of grudge against them for their interference.
* TheHandler: After the end of the first game, he becomes this to Freeman, apparently keeping him as a kind of private mercenary to drop into conflicts in different periods of Earth's future for some unknown ends. He [[SchrodingersCanon may]] also still have Adrian Shepherd on lock and [[spoiler:takes Alyx into his 'employment' as a result of the [[ForWantOfANail events of]] ''[[RetGone Alyx]]'' as a sort of payment for his meddling with her father's original death in ''Episode 2.'' ]]
* HumanAlien: It's made quite clear he is from a different world, since he has supernatural powers and speaks in a way that is described by the developers as "something trying and failing to act human".
* HumanoidAbomination: ''Maybe''. Standing still, he looks human. When he moves — and where he appears — it becomes disconcertingly obvious that he cannot possibly be human.
* InexplicablyAwesome: One of the most intriguing parts of the G-Man is how little we know about ''anything'' about him, including how he does what he does, what he is, who he works for, and what he wants.
* InvisibleToNormals: He can apparently choose which persons are able to see him, and it is hinted that he also has some power over if they remember him or not afterwards.
* ISeeThemToo: The G-Man appears to be invisible to everyone but Freeman and Shephard at times (excluding cameos in ''Blue Shift'' and ''Decay''). However, the Nihilanth, Eli Vance, and the Vortigaunts are all also aware of his existence. Dr. Breen has also implied that he's aware of his employers, what the G-Man did to Gordon in the interim between the first and second games, and that Breen and/or the Combine may have also been involved in a bidding war for Gordon's 'services'. Breen was also implied to be among the "naysayers" who objected to the G-Man saving [[spoiler:Alyx Vance's]] life.
* KickTheDog: [[spoiler:It's subtle, but he seems to take an inordinate amount of pleasure in both "firing" Freeman and putting Alyx Vance in stasis after the events of ''Alyx'']].
* KubrickStare: Has a particularly nasty one in ''Alyx'' aside from a PsychoticSmirk as seen in the trailer (pictured above).
* LackOfEmpathy: Debatable. He saves Gordon's life quite a few times and later [[spoiler:he admits he saved Alyx during the Black Mesa disaster]] suggesting that maybe he's capable of mercy. He also mentions to Shephard that he saved his life specifically because he sees him as a kindred spirit. Considering that he only seems to save people that he sees potential for exploitation in, it's debatable how much emotion is involved. [[spoiler:His sequence in ''Alyx'' also sees him refer to Eli and an Advisor as "This entity", implying he sees ''both'' as being beneath him.]]
* LeaningOnTheFourthWall: [[invoked]] In ''Alyx'', [[spoiler:he comments on Gordon's unreliability, specifically commenting on his lack of progress as of late as a deciding factor to seek a replacement, in an almost tongue-in-cheek nod to the long DevelopmentHell that Half-Life has experienced between ''Episode Two'' and ''Alyx'']], implying that he actually has a measure of MediumAwareness as part of his RealityWarper nature.
* MaliciousMisnaming: Always addresses Gordon as ''Mr.'' Freeman, putting extra emphasis on the "Mr." just to rub it in that he doesn't respect Gordon enough to use his proper title. [[spoiler:This changes once Gordon defeats Dr. Breen.]]
* ManipulativeBastard: From locking out Gordon and Adrian from certain doors, to shoving them in deep-freeze, yeah.
* TheMenInBlack: Doesn't quite fit the trope, but sure as hell evokes the basic concept, probably deliberately.
* MysteriousEmployer: Claims he works for someone, or something, else. Given he seems to have the power to teleport at will and even stop time itself, the fact he is employed by a being presumably [[UpToEleven of greater power]] than himself is either [[BigGood reassuring]] or [[BigBad disturbing]], depending on his [[AmbiguouslyEvil real allegiances]].
* NobleDemon: If we believe what he says, then he saved [[spoiler:both Alyx and Shephard]] when it would have been easier to let them die, and against the direct orders of his employers. [[spoiler:Given that Alyx winds up playing an integral role in his long-term plans, however, it's arguable whether this counts as PetTheDog or not.]]
* NoNameGiven: While he is called "G-Man" in terms of both the credits and his associated character models, he is never actually referred to as this in-story. The only direct reference to him in-game is Eli's label of "our mutual friend." As such, the G-Man is not his actual name or even an InSeriesNickname. In the manual for ''Opposing Force'', Adrian Shephard does call him "'''a''' G-man" in his diary, but this seems to be a generic term.
* NotSoOmniscientAfterAll: All of the player characters are at his mercy throughout the ''Half-Life'' games. It's only ''Episode One'' where the Vortigaunts demonstrate the ability to somehow suppress the G-Man's influence, something that surprises him.
* OffscreenTeleportation: Though there are ''two'' scenes where you get to see him do it: Once in ''Half-Life'' ("Lambda Core"), and once in ''Opposing Force'' ("Foxtrot Uniform"). Played straight several times in ''Half-Life 2'' and its episodes where he can occasionally be spotted in the distance, only to calmly walk away and disappear without a trace when approached. Even more glaring is his habit of appearing to Gordon literally out of thin air ''without'' using a visible portal, so...
* OOCIsSeriousBusiness:
** When he shows even a ''hint'' of anger in ''Episode One'', it's bone-chilling.
** In ''Alyx'', [[spoiler:he shows ''actual'' [[DealWithTheDevil maliciousness]] for the first time in the ending. Not only cruelly leaving Alyx in confusion and fear as he leaves her in stasis, [[YouHaveOutlivedYourUsefulness but tosses Gordon to the wayside]] once freed from his imprisonment.]]
* PetTheDog:
** A debatable example. [[spoiler:He allowed Alyx the use of [[RealityWarping his powers]] to save her father from his death during the events of ''Episode Two'' at the end of ''Alyx'', something he didn't really have to do. He also saved Alyx from the Black Mesa Incident in the first place, and even helped her and Eli escape the facility.]] However, [[spoiler:the ending of ''Alyx'']] leaves it in question whether he did this out of mercy, or whether it was simply a calculated long-term investment.
** Shows a few times to Adrian. He has shown interest in Adrian's safety as early as his initial arrival in Black Mesa when he saved him from the "electrified toxic waste" room. There is also an on-going speculation that the Osprey evacuating the soldiers would not have made it to safety, explaining why he prevented Adrian from boarding it. That said, it is implied the G-Man had an interest in Adrian far before Black Mesa and was responsible for accelerating his training program. While it is plausible that he views Adrian as an "investment" like Alyx, expressing kinship with Adrian over their mutual ability to "adapt and survive" is a praise he afforded nobody else.
* PrecisionFStrike: [[https://www.youtube.com/watch?v=0Uq3kLL3SCA An infamous example]]. In one of the unused Episode 1 lines, he literally says "Well, shit."
* ProgressivelyPrettier: Downplayed. G-Man's design has gradually become more "normal" as the games have gone on; he looks almost [[TheGreys grey-like]] in ''Half-Life'' (though this was likely more due to graphics limitations of the time), with expansions and the later HD textures making him look more human, ''2'' and its episodes normalizing his appearance but settling on otherwise odd touches such as his sunken in, skull-like face and almost glowing eyes, with ''Alyx'' trading out the skull-like look in favor of looking even more like a mundane businessman.
* RealityWarper: Can casually stop time and plant subliminal orders into people.
* {{Retcon}}: He was originally imagined as the administrator of Black Mesa and a literal government agent, but in ''Half-Life 2'' the administrator role was given to Breen.
* ScrewDestiny: His employers (and perhaps, by extension, he himself) seem to believe this, judging by what he says about them in ''Alyx.'' Of course, this being [[AmbiguouslyEvil the]] [[TheSpook G-Man,]] just what ''kind'' of fate they want to fight is unclear.
-->'''G-Man''': Some believe the fate of our worlds is... [[YouCantFightFate inflexible]]. [[ScrewDestiny My employers disagree]]. They authorize me to... ''[[TheChessmaster nudge]]''[[TheChessmaster ... things, hm.... In a particular direction from time to time.]]
* SealedEvilInACan: [[spoiler:Is revealed to be such at the end of ''Alyx'' rather than Gordon by the Combine, somehow. The end of the game sees him set free by Alyx.]]
* TheSpook: All we know is that he's not human.
* SssssnakeTalk: In the first game. Averted in the second game and its expansions, although his speech patterns [[AccentUponTheWrongSyllable remain quite erratic]].
* TheStoic: Has a very emotionless demeanor, though he occasionally expresses slight amusement, and on one occasion the merest hint of anger.
* SufficientlyAdvancedAliens: As far as we can tell.
* TimeMaster: He seems to be able to stop time for his "employees" at the very least. And as shown in ''Alyx'', he can even [[spoiler:rewrite entire timelines, such as him allowing Alyx Vance to save her father from a Combine Advisor at the end of ''Episode 2'']].
* UncannyValley: [[invoked]] Invoked intentionally. WordOfGod states that he's meant to hint at something only ''[[AFormYouAreComfortableWith trying]]'' to look human, but [[HughMann not bothering to try very hard]]. It's especially apparent in ''Alyx'', [[spoiler:where his eyes glow unnaturally at several points, and his face is the most visually emotive in all his appearances, cycling through a variety of emotions throughout his speech...while ''still'' keeping his cold, never-changing monotone, causing a ''massive'', uncomfortable disconnect between the emotion of his voice and the emotion of his face.]]
* UnusuallyUninterestingSight: Whenever he appears he just goes about his business even if there's a huge battle raging around him. Possibly justified as he seems to be invincible.
* VaderBreath: Downplayed. While/before he speaks, the G-Man occasionally inhales dramatically in a way that sounds like someone gasping for air.
* TheWorfEffect: He manages to play ''both'' sides of this trope straight [[spoiler:at the end of ''Alyx''.]]
** On one hand, the mere fact that [[spoiler:the Combine managed to temporarily imprison ''him'' serves as a terrifying reminder that the Lambda Resistance is only fighting a token force of the Combine, and the full might of the Combine is far stronger than anyone could possibly imagine]].
** On the other hand, there are many signs that [[spoiler:the Combine were ''pants-shittingly terrified'' of him.]] They went to the trouble of [[spoiler:building an enormous, space-bending ship that was larger than a city block, and ''executing anyone who even glimpsed it'' - all for the sole purpose of containing the G-man. It still wasn't enough. When Alyx frees him, he's merely... waiting, with the aura of someone who knows he won't be locked up for long. He then proceeds to lend some ability to Alyx that allows her to OneHitKO an ''Advisor,'' one of the absolute top dogs of the Combine Empire.]] In summary, he casually demonstrates that he can completely dismantle the strongest efforts the Combine could possibly make, without even having to dirty his hands personally.
* YouHaveOutlivedYourUsefulness: [[spoiler:Does this to '''[[TheHero Gordon Freeman]]''' at the end of ''Alyx'', disappointed with his lack of progress and deciding to replace him with Alyx instead once she makes a DealWithTheDevil to save her father.]]
[[/folder]]

[[folder:Larry]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/larry_hla.jpg]]
->Voice Actor: Rich Sommer (''Half-Life: Alyx'')
->''"Whoa whoa whoa what! [[OhCrap Jeff is bulletproof]]!"''
An eccentric man Alyx encounters at the distillery. Alyx saves him from a barnacle and in return Larry teaches her how to avoid Jeff.
----
* TheAlcoholic: Implied, by the way he slightly stumbles while standing. Also who in their right mind would ever wander into the quarantine zone, let alone the spore filled distillery on a such a frequent basis to start naming the monsters in there? It's quite clear that he is very fond of the "good stuff" that he gathers.
* DistressedDude: He seems fully capable of taking care of himself considering his equipment and expertise in navigating the quarantine zone while avoiding Jeff, but he made one mistake and got his leg caught by a Barnacle, forcing him to hold on to a railing for dear life. Alyx happened to be nearby to save him when they first meet.
* CasualDangerDialogue: When he thinks he's about to die from being eaten by a Barnacle, he sounds more annoyed over his dumb mistake than anything as the Barnacle tries to pull him away, and asks Alyx for help without much urgency in his voice.
* NiceHat: He has an ingenius anti headcrab helmet, aka a hard hat with nails poking out of it. He also gives you this exact compliment if you happen to sport a hard hat like him when you meet him.
[[/folder]]

!!Xen Aliens
[[folder:Nihilanth]]
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/250px-nihilanth_model_6522.jpg]]
->Voice Actor: Michael Shapiro (''Half-Life 1'')
->'''"FREEEEEMANNNN!"'''
The ruler of the Xen aliens and the main antagonist of the first ''Half-Life'' (and by extension, ''Blue Shift'', ''Decay'' and part of ''Opposing Force''). His race was under severe threat from the Combine, being hunted to near extinction. Sometime prior to the first game, he enslaved the Vortigaunts, who were further pursued by the Combine. To escape them, he and the Vortigaunts fled to the border world, Xen, where they set up shop. Still desperate, he used the Resonance Cascade to launch an invasion of Earth, and despite the Black Mesa's scientists' best efforts to plug the rift between the dimensions, he was able to use his psychic powers to force it to stay open. His forces had success with pushing back the HECU, but his invasion was ended when the Black Ops nuked Black Mesa and Gordon Freeman traveled to Xen and killed him, finally closing the hole in the dimensions.
----
* AlwaysABiggerFish: Invoked by Nihilanth. [[spoiler:He's undoubtedly talking about the Combine, or more specifically the Combine Advisors -- or, quite possibly, who they're advisors ''to''.]]
* AmbiguouslyEvil: Mostly because we know so little about him; what we do know casts him in a pretty ambiguous light. On one hand, he did enslave the Vortigaunts and invade Earth, with his forces being quite indiscriminate in their killings. On the other hand, the Black Mesa scientists had repeatedly invaded Xen to take apparently valuable crystals and specimens (including actually sentient soldiers in the Nihilanth's army), and Marc Laidlaw confirmed that the Nihilanth's invasion of Earth was largely an act of desperation, as his kind had been hunted to near extinction by the Combine. He also seems to care somewhat about Xen's ecosystem, given his apparent horror in the telepathic message he sends to Gordon after Gordon kills the Gonarch (''"Doooone... what have you dooooone?"''), and was the only thing keeping the Combine from invading our universe.
* AndThereWasMuchRejoicing: Given that he was a slaver who is implied to have been oppressing the Vortigaunt kind for eons, his loss is not particularly mourned by his Vort kin.
--> "We bear witness to the bright eternity of the Nihilanth's demise."
* AttackItsWeakPoint: The only way Freeman can kill the Nihilanth is to fire everything he's got directly into its brain. Even then, it takes quite a bit of damage.
* AuthorityEqualsAsskicking: Just like the Combine Advisors, he leads a large army and has very powerful telekinetic powers, which include the ability to teleport himself and others, telepathy, the ability to shoot extremely powerful balls of lightning, and levitation. His commanders and possible relatives, the "Alien Controllers", also possess these abilities, but to much less powerful degrees.
* BigBad: Of the first game, and by extension, ''Decay'' and ''Blue Shift''.
* BigBadEnsemble: Between himself and his forces, Race X, the HECU, and the Black Ops in the first game and its expansions.
* BlackEyesOfEvil: His eyes appear plain black, unlike his underlings, whose eyes are red. He may not even have eyes, just holes where they should be like the Stalkers, but it's hard to tell.
* BodyHorror: In addition to his general creepy anatomy, he also has what appears to be amputation scars on his chest, shackles, and mutilated legs that have been burned to vestigial stubs. But Marc Laidlaw denies that this is the result of being captured by the Combine, which is a common fan theory.
* ColorCodedForYourConvenience: His orbs all have distinct roles, and are distinguished by color and shape.
** Blue: Balls of energy that kill anything they come into contact with.
** Green: Teleports whoever it touches.
** Gold: Provides a powerful personal shield that protects him from damage.
* EnergyBall: Can launch dozens of energy balls at a time; they each deal a ton of damage, but they can be (barely) avoided with strafing because Gordon Freeman can [[RoadRunnerPC strafe at over forty miles per hour]].
* EvilSoundsDeep: Has a voice that can probably be best described with adjectives like "vast" and "bellowing."
* FatBastard: His torso looks a little more human-like than the other Xen aliens, making it somewhat noticeable that he looks overweight. This is likely the result of his legs being vestigial, and him floating around everywhere.
* FetusTerrible: What he looks like.
* FinalBoss: Of ''Half-Life 1.''
* FlunkyBoss: As a secondary attack, the Nihilanth can launch a green orb that either teleports you to another room or spawns some Vortigaunts or [[invoked]][[GoddamnBats Alien controllers]] in his chamber. The second option isn't so bad, since he only spawns a few at a time, but him teleporting you to another room is very frustrating. In one instance, he'll teleport you to a room with a Gargantua, forcing you to have a boss fight ''in the middle of another boss fight''.
* {{Foreshadowing}}: His telepathic messages drop quite a few hints in regards to the Combine, the G-Man, Gordon, and possibly Breen and Shephard.
-->"[[GreaterScopeVillain Their slaves... we are their slaves... we are...]]"\\
"Deceive you... he will deceive you..."\\
"[[ISeeThemToo Alone... not you alone... not you alone]]"\\
"You are man... he is not man... for you he waits... for you..."\\
"[[WhatTheHellHero Done.. what have you done...]]"
* LoadBearingBoss: Killing the Nihilanth causes him to explode, which knocks Gordon out.
** Also one in-story; his psychic powers were the only thing keeping the portals between the Combine's universes and Xen closed. When he died, the Combine were free to pour through Xen, and then to Earth.
* LargeAndInCharge: The largest alien ever encountered in the series in terms of pure size. Even bigger than the three-story tall tentacle monsters.
* LastOfHisKind: WordOfGod reveals that the Nihilanth's species was systematically wiped out by the Combine, something he himself alludes to just before Gordon enters his chamber:
--> '''Nihilanth:''' "...The last. I am the last..."
* LeaningOnTheFourthWall: Much like the G-Man and the Vortigaunts, most of his comments may be just as much about the player as they are about something in-universe, and open to many theories. For example, in the quote below, he is both the last of his kind, possibly the last thing keeping the Combine away from Earth, and the ''last boss''.
* MeaningfulName: [[invoked]] WordOfGod says "Nihilanth" is meant to imply nihilism. The ''-anth'' suffix relates to the flower-shape of his head.
* MightyGlacier: The Nihilanth has some of the strongest attacks of any Xen alien. However, thanks to his slow, deliberate movements, the attacks take a long time to prepare, giving Gordon ample time to find cover. The Nihilanth is also a huge target, and he can't move horizontally, only capable of slowly turning around in place or moving vertically.
* MyBrainIsBig: His head takes up over half of his entire body!
* PivotalBoss: He never moves from his point in the center of his room. Also...
* PowerFloats: Nor does he touch the ground.
* PsychicPowers: The only psychic seen so far, aside from possibly the G-Man, who can affect things on a planetary scale. He was able to keep open a dimensional rift, telepathically mind control an entire species, and, judging by what happened after he died, was powerful enough to trigger disastrous portal storms all over the Earth, resulting in Xen wildlife killing off most of Earth's native fauna. Compared to that, his personal combat abilities (which are still formidable) seem rather unimpressive.
* PuzzleBoss: To actually damage him, you need to find out that he is using the crystals to regenerate his force field and destroy the crystals. After that, his protective orbs won't regenerate, and he can be killed, but it takes quite a bit of damage.
* SayMyName: The very first thing he says to Gordon in person is a chilling, angry bellow: "'''FREEEEEEEEEEEMAAAAAAAN...'''"
* ShockAndAwe: The Nihilanth chiefly attacks with lightning ball attacks. The projectiles don't even have to touch Gordon directly to damage him; if they're close enough, they fire beams of electricity at their targets.
* StrangeSyntaxSpeaker: His speech pattern is best describe as being similar to [[Franchise/StarWars Yoda's]] speech but with making a point by repeating himself.
* StrawNihilist: Both his name and his cryptic comments to Gordon imply that he long since crossed the DespairEventHorizon and become a nihilist.
* {{Telepathy}}: He broadcasts telepathic messages to Freeman all throughout Xen, and can also use this ability to communicate with other Xen creatures.
* TurnsRed: Surprisingly, throughout the battle with him, [[InvertedTrope his attacks become progressively]] ''[[InvertedTrope weaker]]''. Before his forcefield is destroyed, he's able to throw dozens of projectiles at a time. After the forcefield is destroyed, he can only muster the energy for a single projectile, taking just as long to prepare it as he would with a full set of them.
* WellIntentionedExtremist: [[spoiler: The Nihilanth invades earth, slaughtering dozens of innocents, and runs a bizarre slave-like society in Zen, but they do this to stop The Combine, [[EvilVsOblivion who are ''far'' worse]].]]
* WhatTheHellHero: The Nihilanth is actually warning Freeman the ''entire'' game to ''cut it out'' ("Deceive you... will deceive you...", "Their slaves... we are their slaves... we are...", "The truth... you can never know... the truth...") [[spoiler:Basically, the Nihilanth was the one thing preventing the Combine from invading Earth.]]
[[/folder]]

[[folder:Vortigaunts]]
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/vrt_4948.png]]
-> Voice Actor: Lou Gossett Jr. (''Half-Life 2''), Creator/TonyTodd (''Episode Two'', ''Alyx'') (English), Diran Megreblyan (''Hal-Life 2''), Nikita Prozorovsky (''Episode Two'') (Russian)
->''"We bear witness to the [[AndThereWasMuchRejoicing bright eternity]] of the [[FinalBoss Nihilanth]]'s demise. You leap, you fall, we see you flash between the barriers."''
A race of peaceful aliens linked to something called the Vortessence. They were enslaved by the Nihilanth as factory workers and militia, and were one of the most common enemies in the original ''Half-Life''; after the fall of the Nihilanth, they were free to converse with humanity and, come the arrival of the Combine, join the Resistance.
----
* AliensSpeakingEnglish: Interspersed with their native language and phrases.
* AlternateCompanyEquivalent: In the first game and its expansions (and mods), Alien Slaves were direct counterparts to the Imps from ''VideoGame/{{Doom}}'', which several ''Half-Life'' developers cited as a key inspiration for the game. Red eyed, hooved, hunchbacked, brown-skinned, clawed, screeching, CannonFodder [[TheGoomba goombas]] visibly at the bottom of the enemy hierarchy, who go down after a few pistol rounds and attack by either throwing a powerful but easily avoidable projectile or clawing with their superhuman strength in melee range. They became distinct when ''Half-Life 2'' and its expansions started giving them actual character.
* BinomiumRidiculus: They are referred to with the scientific name "Xenotherium subservilia" (Subservient alien beast).
* BizarreTasteInFood: In ''Half-Life 2'', the "All-Knowing Vortigaunt" is roasting a Fast Headcrab on a spit. This is reinforced in ''Alyx'', where the Vortigaunt that helps the titular character can be seen cooking and eating headcrabs in his hideout. He offers one to Alyx, though she doesn't follow suit.
* DeathIsCheap: Apparently, via the "Vortessence":
--> ''"What seems to you a sacrifice is merely, to us, an oscillation. We do not fear the interval of darkness."''
* EasilyForgiven: Played with: the vortigaunts don't seem too upset about you killing scores of them in the first game. Justified as you had no choice but to fight them and the surviving vortigaunts see what you did as more of a MercyKill. On the other hand, speaking to a vortigaunt enough gets you this line:
--> ''"We cannot forget those whose cords you cut. Forgiveness is not ours to bestow."''
* FateWorseThanDeath: The All-Knowing Vortigaunt states that Freeman did the enslaved Vortigaunts a favor by killing them. [[spoiler:Considering the Lone Vortigaunt in ''Alyx'' was forcefully cut off from the Vortessence and the Vortigaunt HiveMind, it's likely that the enslaved Vortigaunts from [=''HL1''=] suffered the same fate.]]
* GutturalGrowler: All the Vortigaunts have quite raspy and deep voices.
* HeelRaceTurn: Since the original ''Half-Life''. They weren't actually evil in the first place, as they're enslaved by the Nihilanth. After Gordon frees them, the Vortigaunts aid the LaResistance against the Combine.
* HiveMind: Or at least an entire race somehow connected on a metaphysical level by the Vortessence...Whatever ''that'' is.
* InterspeciesFriendship: By the time the events of ''Half-Life 2'' roll around, the surviving humans and Vortigaunts left on Earth have formed a friendship with each other, and are more than willing to team up with each other to take down the Combine at all costs.
* {{Lightworlder}}: Considering the Vortigaunts spent a good amount of time in Xen (which has lower gravity than Earth), they could count as such. Although, how much they're considered true lightworlders is left ambiguous, because they adapted to Earth's gravity very well and have SuperStrength. Not to mention that details about their actual homeworld are never revealed.
* MagicByAnyOtherName: They can shoot lightning, they can charge your suit, they can heal [[spoiler:critically-injured Alyx]], and power generators. And it's all just put down to "the Vortessence"
* MediumAwareness: Ambiguously so. Some of their dialogue implies that they are either aware of the player or the G-Man.
--> ''"Far distant eyes look out through yours."''\\
''"Could you but see the eyes inside your own, the minds in your mind, you would see how much we share."''\\
''"How many are there in you? Whose hopes and dreams do you encompass?"''\\
''"Something secret steers us both. We shall not name it."''
* NotAlwaysEvil: In the first game, they were typical {{Mooks}} for Gordon Freeman to mindlessly kill. It turns out, they were only fighting you because they were enslaved by the Nihilanth, and they help LaResistance in the second game and its episodes. (Sharp eyes at the time noted they were wearing control braces. That and their name in the game files was ''alien_slave'') Whoops. The G-Man tries to make Gordon feel guilty about this later on.
* OneManArmy: You didn't think that the humans were the only ones with these, did you?
** X-8973 and R-4913, the two Vortigaunts from the UsefulNotes/PlayStation2 exclusive expansion, ''VideoGame/HalfLifeDecay''. They are noticeably more durable than standard Vortigaunts, have stronger and seemingly more developed electrokinesis, and can regenerate health by damaging enemies. Something of a downplayed example though, as they work as a team and only get to take down twenty or so soldiers in the small bonus chapter in which they appear.
** The three Vortigaunts in ''Episode Two'' who slaughter dozens of antlions, turning what used to be a tough HoldTheLine moment into a glorious CurbStompBattle. The one that accompanies you throughout the mines, nicknamed the Victory Mine Vortigaunt, is probably the best example.
* ScrewThisImOuttaHere: On the harder difficulties in Half-life, Vortigaunts wounded enough will simply stop attacking and try to run away from Freeman. Though they'll still attack if cornered [[ISurrenderSuckers or if Freeman turns his back to them.]]
* ShockAndAwe: Their primary attack is releasing bolts of lightning from their fingertips and, later on in the series, can even thrust their energy-charged hands to the ground to create a potent energy-based shockwave for a better crowd-control attack.
* SlaveMooks: In the first game, but then Gordon Freeman freed them from control of their alien masters.
* SlaveRace: They've been enslaved by both the Nihilanth and the Universal Union long before the events of the first game.
* SquishyWizard: Only when in relation to the powers of the Vortessence, given their OneManArmy feats and SuperStrength. ''Episode One'' and ''Episode Two'' demonstrate that the Vortigaunts possess immense psychic powers that rival the abilities of the G-Man, but the Combine's many Vortigaunt victims (one of whom can be found in Nova Prospekt) and Gordon's own body count during the Black Mesa Incident also shows that they're just as vulnerable to physical danger as humans are.
** Even the playable Vortigaunts in ''Half-Life: Decay's'' bonus levels are noticeably more fragile than the other player characters due to the lack of armour system that [[VideoGame/HalfLife1 the]] [[VideoGame/HalfLifeDecay HEV/]][[VideoGame/HalfLifeOpposingForce PCV/]][[VideoGame/HalfLifeBlueShift kevlar-wearing]] human protagonists have, [[FragileSpeedster relying on speed and mobility to defeat the HECU grunts.]]
* SpellMyNameWithAThe: They ''always'' call you and Alyx "The Freeman and the Alyx Vance".
* StarfishAliens: {{Downplayed}}. While Vortigaunts still have a [[HumanoidAliens humanoid shape]], that's where the physical similarities between them and humans end. They have at least four eyes, three arms, [[ShockAndAwe lightning powers]], and some sort of HiveMind (that may or may not overlap with the very (vort)essence of the universe).
* StarfishLanguage: Vortigese and the related "flux-shifting" ranges from a 'normal' spoken language to telepathy to a language where two vortigaunts have to talk ''at the same time'' to properly communicate.
* SuperStrength: While it is not as pronounced as the strength of the Grunts, they still have it. The very first time you encounter one, it breaks down a 20mm thick heavy metal door with a few hits, with the door being reduced to pieces.
* TookALevelInBadass: In the first game, they were disposable mooks, slaughtered in droves by Freeman and the soldiers. By ''Half-Life 2'', they're much more powerful combatants (individually about on par with the original's Hard mode Vortigaunts) and have gained new mystical abilities including, at one point, resurrecting someone from the dead. In ''Episode One'' they also demonstrate the ability to suppress the powers of the reality warping, time traveling G-Man himself.
* TimeTravelTenseTrouble: The Vortigaunt that helps Alyx in her titular spin-off has this as a result of a lobotomy performed on him by the Combine; Since the Vortigaunts can see into the future through others of their kind, they can know what will or or has happened. However, since he had been cut off from the Vortessence, he gets confused as to whether he's seeing the future, past, or present.
* WhatIsThisThingYouCallLove: [[spoiler:Implied in ''Alyx''. When Eli and Alyx say tell each other they love them before heading their separate ways, the Vortigaunt who accompanies Eli repeats it to Alyx, albeit in an awkward and stilted way, as though he has never heard the phrase or understand what it means.]]
[[/folder]]

[[folder:Headcrabs and Zombies]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/headcrab.png]]
[[caption-width-right:350:Clockwise from Top Right: Standard, Gonarch, Fast and Poison]]
Parasitic alien lifeforms. Originally from an unknown dimension far from Xen, they were eventually brought there by the portal storms. After the Resonance Cascade and the following portal storms, the headcrabs migrated and set up shop on Earth. Their most notable quality is their ability to turn humans (and possibly other creatures) into Zombies by attaching to their heads.
----
* ActionBomb: Zombine will sometimes decide to pull their grenade out and sprint at their enemies to explode on top of them. Whether this is a conscious act by the Combine soldier or a calculated move by the Headcrab isn't known.
* AndIMustScream:
** Victims of headcrabs in ''2'' are more than likely still alive and conscious, even when the alien is controlling the rest of their body and actively mutilating their innards to better suit its purposes.
** Playing the standard Zombie audio backwards in ''2'', ''Episode One'' and ''Episode Two'' reveals that they're begging for help and wailing in pain when lit on fire. This was made more obvious in ''Alyx'' where Zombies don't speak backwards anymore and are more intelligible.
** Combine zombies, [[PunnyName Zombine]], are either conscious enough or are so brainwashed by their training that they [[https://www.youtube.com/watch?v=hYTup2PFTEI actively point out that their area is infested with headcrabs]], saying things like ''"Sector is not secure"'' and ''"Biotics in perimeter"'' into their radios in pained expressions.
* ArtifactMook: In ''Half-Life 2'', they (and, occasionally, their victims) are often found in abandoned areas, even when there are no headcrab shells around. This is mostly seen in "Highway 17". In fact, the very last headcrab you can encounter in the main ''Half-Life 2'' is right outside of the Citadel at the start of "Our Benefactors".
* BodyHorror:
** For unknown reasons, headcrabs mutilate a persons body, possibly because as a parasite they are draining its "resources". Standard Zombies have their ribcages open like teeth and their organs are on display. The bloodied faces of the victims aren't much better. In the original ''Half-Life'', it appeared some of the mutations happened as a result of the headcrab ''fusing'' with the victim, becoming a warped mass of flesh overtop the skull.
** It gets worse with elite zombies. Fast Zombies look like all of the flesh save the bare muscle is gone. The Poison Zombies are being eaten away: they have a smashed in looking "face", an exposed skull, and an exposed spinal column. Gonomes from ''Opposing Force'' have even the headcrab undergoing some substantial effects, with its front limbs withering away after having effectively become the host's new face.
* ButtMonkey: In a way they are this, even if they are pretty damn creepy. They are usually getting obliterated by both Combine and rebels, and even the game actively encourages you to kill them in "creative" ways such as throwing saws, using traps, or setting them on fire. Of the four factions competing for control by the end of ''Half-Life 2'', they are probably the weakest, with their only saving grace being their sheer numbers.
* CatScare: A single lowly Headcrab or its Zombie are sometimes set up to spook the player but otherwise pose a minimal threat. Poison Headcrabs are a favorite to use in particular for their unsettling shrieks and ability to wipe out an entire HP reserve for a few seconds, but are otherwise harmless when fought alone.
** At two separate points in Route Kanal, crouching into hidden crawlspaces for hidden supplies will also yield a severed Zombie torso that crawls after the player.
** After exiting Ravenholm, likely when the player is sick of fighting off Zombie and Headcrab hordes and relieved to see the sun again, a lone Poison Headcrab is hidden behind some crates at the tunnels exit as a farewell for the player.
* TheDeterminator: Some of the zombie types count as this, as even after being [[HalfTheManHeUsedTobe cut in half]], they will still crawl around using their arms trying to get at Gordon.
* EliteMooks: In the first game, there were just basic headcrabs and zombies. The later games introduce new forms.
** ''Opposing Force'' has the Gonome, a mutated version of the standard headcrab zombie. Not only does it have more health than a normal zombie, but it can throw some sort of projectile and sprint.
** ''Half-Life 2'' introduces the fast headcrabs and poison headcrabs, as well as their accompanying zombie forms.
** ''[[VideoGame/HalfLifeAlyx Alyx]]'' adds armored headcrabs that only take damage from their underbelly, as well as the "lightning dogs"; an offshoot headcrab breed with a tail that can fling energy projectiles, spawn a smoke cloud to obscure the player's vision, and re-possess slain zombies to give them a harmful aura of electricity.
* EyeScream: In ''Alyx'', older Headcrab victims have the their faces seemingly digested away, with their eyes in particular missing, leaving emptied and bloody sockets. It seems to only apply to old victims, as new hosts still have their eyes and face intact, if warped from living their Headcrab for a while.
* FaceFullOfAlienWingWong: Which causes Barney to refer to them as "head humpers".
* FateWorseThanDeath: [[https://youtu.be/U8eSRBHw88w?t=7 Headcrab zombies can be heard crying out in pain]], and playing their audio backwards reveals a large amount of dialogue such as "God Help Me! Help me!" or "Get it off me!" This heavily implies that headcrab victims are aware of what's happening but unfortunately there is no way to remove headcrabs [[MercyKill without killing the victim]].
** If there was ever any doubt for their victims awareness after being overtaken, Zombies in ''[[VideoGame/HalfLifeAlyx Alyx]]'' no longer speak backwards and are [[https://youtu.be/trHUpL3r8U8 audibly heard crying in pain and shouting coherent pleas for help.]]
* FlunkyBoss: The Gonarch continually spawns baby headcrabs that attack Gordon relentlessly.
* FragileSpeedster: Invoked for all of the Headcrab variants, of course, who can all pounce a large distance to take a bite out of the player, but go down in a few hits to basically anything.
** Fast headcrab zombies are the fastest ones by far, and are arguably the most dangerous for this reason. However, they have no more health than a standard zombie, and so are only a big threat in large numbers and [[GoddamnedBats being pretty annoying as well]].
* GlassCannon: While the Poison Headcrab is only a little more durable than the more common variants, it can temporarily reduce the player's [[HpToOne health to 1 HP]] and thus, leaving the player vulnerable to other enemies.
* TheGoomba: Both the zombies and the headcrabs themselves, with the former being almost a complete non-threat due to their slow speed, low health, and weak attacks, and the latter dying in one or two hits from just about anything and doing next to no damage.
* HellIsThatNoise: Headcrab noises are all horrible, whether alone or from a zombie. Special mention has to go the poison headcrabs which make three distinctive noises: a disarming chirping noise, a rattle that sounds like a rattlesnake rattle, and when they attack they let out a horrible high-pitched scream that sounds almost human.
* KingMook: The Gonarch is a queen headcrab.
* LightningBruiser: Puns aside, the "lightning dogs" from ''Half-Life: Alyx'' are this. Although their lightning attacks don't do a lot of damage on their own, they're fast and skittish and are capable of tanking multiple shotgun blasts before dying.
* MamaBear: The Gonarch is not affiliated with the Nihilanth in any way, she's just a headcrab queen trying to protect her young from (in her eyes) a violent armored alien monster invading her nest.
* MascotMook: They've become this due to being unique but common enemies.
* NonMaliciousMonster: Like the Antlions, despite being quite threatening and a dangerous threat to both Combine and Resistance operations, they're not really evil and only operate on a basic animal-like intelligence.
* NotSoHarmlessVillain: Due to how easy it is to kill them, it's easy to forget just how dangerous they can be. For proof just look at [[BleakLevel Ravenholm.]]
* OffWithHisHead: Zombine, when killed with a powerful blow like a headshot or explosion, will send their headcrab flying off and reveal the Combine soldier's head to be severed by the jaw hinges. Presumably, the headcrab hung on so tightly around their helmet that blowing it off just ended up tearing half its victim's head away.
* PersonalSpaceInvader: They have a habit of flinging themselves at people's heads.
* PunnyName: Zombine - who are zombified Combine soldiers.
* PuppeteerParasite: They effectively replace their victims heads, controlling their every actions. There seems to be enough of their host's mind left [[FateWorseThanDeath to be horrified at their predicament]].
* TragicMonster: Each of the zombies used to be human, and are implied to still feel real pain and possible sentience.
* WhiteShirtOfDeath: All the classic zombies in ''Half-Life 2'' and episodes wear very bloody white shirts.
* ZergRush: Zombies are fond of this tactic in Ravenholm and City 17, post-collapse of the Sector 17 Overwatch.
* ZombieApocalypse: Can cause this if they show up in large numbers. The Combine exploits them as a terror weapon for this exact reason, firing torpedoes loaded with headcrabs to create infestations in areas held by the rebellion, such as the town of Ravenholm.
[[/folder]]

[[folder:Antlions]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/hl2_antlions.jpg]]
[[caption-width-right:350:Clockwise from Top Right: Worker, Soldier, Guardian, Grub, Guard]]
Large, insect like creatures that migrated to Earth following the portal storms. They seem to operate much like many Earth insects, living in extremely large colonies with other antlions. After the events of ''Half-Life 2'', the street war between the Combine and the Resistance has caused a breakdown of the Combine defenses, and the antlions have started pouring in to civilized areas.
----
* AlienKudzu: Implied, as they're so ridiculously common on Earth ever since the invasion that the coast is lousy with Antlions, to the point where merely walking on the beach is enough to incur the wrath of the hive. Antlions, Leeches, Seagulls and occasionally Headcrabs are the only creatures still found living on Earth's beaches.
* AttackAnimal: They can be commanded and used as expendable assault teams by anyone who has the Antlions' pheropods in their possession. Gordon Freeman uses the pheropods to his advantage during ''Half-Life 2'', essentially gaining his own private army to let him and Alyx Vance effectively storm Nova Prospekt all on their own. The main issue, of course, is that one needs to first kill an [[GiantMook Antlion Guard]] in order to get these pheropods.
* BigCreepyCrawlies: They resemble Earth's arthropods, albeit over-sized. Even their offspring resemble beetle grubs.
* CallASmeerpARabbit: Besides living in sand, they don't resemble real-life antlions.
* CannonFodder: Antlion soldiers. The most commonly encountered ones by far, they pretty much just charge and attempt to bite/claw whatever is threatening the colony with little regard for personal safety. They can jump pretty far and quickly maul normal humans with their teeth and claws,[[note]]They are in fact specifically coded to kill human soldiers in one hit, despite only doing 5-10 points of damage to Freeman.[[/note]] but lack external weapons or any real intelligence. Good thing they're extremely numerous.
* DefeatEqualsExplosion: Antlion workers explode when they die, shooting acid everywhere.
* EliteMook: Antlion workers, which use their wings to jump around more often, have twice as much health as Antlion soldiers, and spit acid with deadly accuracy.
* EvilVersusEvil: Their presence is quite a help to the Resistance, as it gives the already overstretched Overwatch occupation force something else to shoot at. Though to be fair, they're not ''evil'' so much as animalistic. Once Gordon gets the pheromones, they're actually pretty helpful allies.
* {{Expy}}: Especially the basic soldiers look and behave ''a lot'' like the Bugs from the ''Film/StarshipTroopers'' films.
* EyelessFace: It can be hard to tell, but they have no eyes and so rely on pheromones to tell friend from foe.
* GiantMook: Antlion Guards, which can soak up bullets and grenades like a sponge and punt [=APCs=] with a headbutt.
* InsectoidAliens: They greatly resemble giant beetles. Their grubs also resemble giant maggots.
* MadeOfPlasticine: Antlions are the only enemies in ''Half-Life 2'' that can be gibbed.
* MamaBear: Don't mess with their grubs. Seriously, don't.
* MysteriousPast: [[ItMakesSenseInContext In a sense]], with them having some unknown connection to the Vortigaunts (who have even domesticated some of their species to a certain extent).
* NonMaliciousMonster: Like the Headcrabs, despite being incredibly dangerous and a significant threat to both Combine and Resistance operations, they're not really evil and only operate on a basic animal-like intelligence.
* UnstoppableRage: If you mess around with Antlion grubs, the Antlion Guardian will. Get. ''Pissed.'' The Guardian that appears in ''Episode Two'' actually [[RoaringRampageOfRevenge leaves the nest to hunt down and kill]] Freeman in revenge for breaking in and killing their young.
* ZergRush:
** During ''Half-Life 2'', they have a tendency of doing this -- they will even push the player onto the sand, summoning more Antlions.
** During ''Episode Two'', they do this once Gordon reaches Griggs and Sheckley's hideout. Fortunately the aforementioned rebels are quite adept at killing them, not to mention they have two turrets as backup.
[[/folder]]

[[folder:Barnacles]]
[[quoteright:200:https://static.tvtropes.org/pmwiki/pub/images/barnacle_8478.jpg]]
Large, stationary creatures that wait on the ceiling for prey to wander in range, where upon they grab their prey with their tentacle and pull it up into their mouth.
----
* ExtremeOmnivore: They'll eat just about any living thing, from humans to Antlions to birds. On the other hand, should they pick up something they ''cannot'' eat such as wood, they'll chew it a little, get frustrated and spit it out.
* GlassCannon: Despite it can be killed easily with any conventional weapons, the Barnacle can mow down an NPC including the player in few seconds while chewing in the first game. While in its sequel, it will [[OneHitKill instantly kill an NPC]] via NeckSnap. However, the player can take [[CherryTapping 10 damage points per bite]], thus giving the latter enough time to whack the said beast.
* NeckSnap: How they instantly kill non-player characters in the second game. Freeman is immune, possibly due to his HEV Suit.
* OverlyLongTongue: Weaponized, as they wait for prey to wander into their dangling tongues and drag them up to devour them.
[[/folder]]

[[folder:Alien Grunt]]
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/afe9c957e253c193317aee8a60577d61.jpg]]
The backbone of the Nihilanth's Xenian army in the first ''Half-Life''. The Grunts are tall, bipedal, muscular creatures with multiple red eyes, backward jointed legs, tube ears, vertical opening mouths, and an arm sticking out of their chest, similar to the Vortigaunts. They make up a large part of the invasion force during the Black Mesa Incident, where the Nihilanth's forces squared off against the HECU.
----
* ArmorIsUseless: In regular ''Half Life'' their armor is actually quite powerful and deflects most attacks that hit it, but in ''Half Life: Source'' it actually does nothing, because the engine is unable to handle different materials on a single character model.
* BeeBeeGun: Their weapon, the Hivehand, which shoots alien "thornets", which are less like bees, and more like flying, poisonous, heat seeking armor-piercing daggers of death that can find you ''anywhere''
* {{Cyborg}}: Their armor and weapons look like they have been surgically grafted on to their bodies, and the Grunts themselves are artificially created in a factory.
* DumbMuscle: Averted. While their strength is mainly emphasized over their smarts, they clearly use strategy in their skirmishes. They use tactics such as firing their Hivehands to track those hiding behind cover and running between cover themselves when the opportunity sees fit.
* EliteMooks: They're much more dangerous than Vortigaunts, the other foot soldier of Xen in the first game, due to their high health, heat seeking projectiles, and armor.
* NoSell: Shooting the armored parts of the Grunts will simply do no damage at all if you shoot them with a pistol, shotgun, assault rifle, or even an uncharged Tau Cannon[[note]]What the armor does is subtract a flat 20 points of damage from any projectile that hits it, so any non-explosive other than a .357 magnum round, a crossbow bolt, or a sufficiently charged tau cannon shot ends up doing 0 damage, while even attacks that deal damage will still do reduced damage[[/note]]. Oddly enough (and good for the player), their armor is placed just about everywhere ''but'' the Grunt's torso, the most likely place it is to get shot.
* MultiArmedAndDangerous: Continuing the Xen theme as seen in Vortigaunts and Controllers.
** This isn't all they share; like the Controllers, they also have the Vortigaunts' red eyes, vertical opening mouths, backwards jointed legs, hoofed feet, [[HumanoidAliens bipedal posture, two legs]], and claws (well, on their third arm at least).
* MoreTeethThanTheOsmondFamily: It can be hard to tell, but their mouths consist of several razor-sharp teeth arranged vertically (think like the teeth on a zipper).
* OrganicTechnology: Their main weapon, the Hivehand, mentioned above, is a textbook case. This trope applies to the Grunts themselves, as they are a...
* ServantRace: Towards the end of the game, you can find a factory run by Vortigaunts, with several barrels on an assembly line. Opening these barrels will reveal Alien Grunts, with the implication being that the Grunts are a manufactured species, fitting in with the general bio-technology theme of Xen.
* SuperStrength: In various scripted scenes, they're seen doing things like prying open steel doors with their bare hands, or punching marines through metal walls.
[[/folder]]

[[folder:Gargantua]]
[[quoteright:200:https://static.tvtropes.org/pmwiki/pub/images/gargantua_1115.png]]
The tanks of the Xen forces. The Gargantua is a twenty foot tall blue creature with an armored shell, two vestigial arms, two functioning arms, and one large eye. Their main arms have pincers that can open to emit jets of blazing heat. They only appear a few times, but you ''will'' remember them.
----
* AmbiguousRobots: Their seemingly metallic skin and built in weapons makes one wonder. They actually share a few traits with Combine synths.
* CyberCyclops: Gargantuas have a large single red eye, and they seem to be biomechanical creatures.
* {{Cyborg}}: Possibly. It does look pretty mechanical. Special mention goes to its built in weapons, glowing machine-looking eye that changes colors, and armored metallic skin. Not to mention the way they explode.
* DeathFromAbove: How one is taken out at the end of ''Surface Tension''; Freeman calls in an air strike on it, and the HECU aircraft, not knowing who sent the signal, are happy to oblige. Cue exploding Gargantua.
* KillItWithFire: They have flamethrowers built into their arms.
* LightningBruiser: Don't let their big size fool you into thinking they're slow as molasses because they can run just as fast as you can, or ''even'' faster. While their only ranged attack is a slow foot stomp that's easy to dodge, Gargantuas have a pair of ''gnarly [[PlayingWithFire flamethrowers]]'' that will melt your health '''very quickly''' and these guys not only take ''tons'' of hits to kill, normal bullets [[NoSell don't work against them]], forcing you to use explosives, energy weapons, or traps. This is taken a step further in ''VideoGame/BlackMesa'' where Gargantuas are ''completely immune to your weapons'', and they can only be killed by scripted events.
* MadeOfIron: Bullets just bounce harmlessly off their skin. It takes a TON of explosive or electrical damage to actually put them down, more than the actual M1 Abrams tanks in the game. Even more so in the mod ''Videogame/BlackMesa'' (a recreation of ''Half-Life 1'' in [=HL=]2's engine), where there is absolutely no conventional way to kill them, even with all the explosives the player can carry; they can only be taken down with scripted sequences.
* MeaningfulName: '''Gargantua''', as in it's an absolute behemoth.
* MiniBoss: They serve this role whenever they appear in the original ''Half-Life''; they're very tough, and half the time are meant to be taken down in scripted sequences to boot, but don't last as long and aren't as powerful as the actual bosses, of which there were only three (the [[PuzzleBoss Tentacle]], the [[DamageSpongeBoss Gonarch]], and the [[FinalBoss Nihilanth]]).
* NaturalWeapon: They can open their arms to release streams of fire/plasma/something that's powerful enough to actually reduce a human to LudicrousGibs rather than just burn them. They're also fond of simply crushing their enemies, or shooting a weird energy beam by stomping on the ground that can seek out targets and, again, gib them.
* PuzzleBoss: Every one you meet is intended to be taken out using the environment in some way. You ''can'' kill them with weapons, but it requires almost your entire inventory of explosives to do so.
* RedEyesTakeWarning: They sport a large red eye. The ''Black Mesa'' mod makes their eye glow brightly, giving them an even more menacing appearance than before.
* TheJuggernaut: Bullets don't do a damn thing against it what with its metal carapace, and even if its still susceptible to both energy weapons and all explosives it's going to take a lot of ammunition to bring it down. It also still says a lot when the only things to one shot it are very strong discharges from a power station or a direct hit from a mortar strike, both instances being very coincidental.
* WalkingTank: Notable because they actually resemble a giant version of the primary Xenian heavy infantry unit, the Alien Grunt. Both are bipedal, both have backwards jointed legs, hoofed feat, red eyes, multiple sharp teeth, and two arms ending in weird hand-less ends that open up. [[http://images2.wikia.nocookie.net/__cb20090328052919/half-life/en/images/thumb/6/6b/Gargantua.jpg/250px-Gargantua.jpg See]] [[http://images.wikia.com/half-life/en/images/7/75/Garg_hand_detail.jpg for]] [[http://images.wikia.com/half-life/en/images/2/23/Alien_Grunt_hd_nohh.jpg yourself.]] This the only real hint we get it in-game that they're part of the Xenian military rather than just wild animals... well, that and the fact that they don't attack sentient Xenians the few times its possible to get Gargs and Vortigaunts in the same room. The same doesn't apply for Xenian wildlife.
[[/folder]]

[[folder:Alien Controller]]
[[quoteright:192:https://static.tvtropes.org/pmwiki/pub/images/alien-controller_7851.png]]
Psychic aliens with gigantic heads that can levitate and generate blasts of destructive energy from their own bodies. They are the masters of the various Xen aliens and are implied to even control some of them psychically. They are much smaller and less powerful versions of the Nihilanth, though whether they are truly the same species is unclear. They barely take part in the war on Earth, mostly remaining in Xen itself.
----
* AirborneMook: They fly around using psychic powers, which can make them very annoying to hit.
* {{Cyborg}}: Not inherently obvious on the in-game model, but early model renders show them to be immensely mechanical.
* DyingRace: According to Marc Laidlaw, they became either this or just outright extinct after the death of the Nihilanth.
* EnergyBall: Their main method of attack.
* LevitatingLotusPosition: They strike this pose of the "hands closed together" variety whenever they launch their energy bolts at you.
* MadeOfIron: Despite being [[SquishyWizard squishy looking]], Controllers can take more damage than even the fully armored HECU soldiers, and much more than the Vortigaunts. This is likely because they have a weaker, invisible version of the Nihilanth's psychic shield, as they share many other abilities with him and do not visually wear any armor.
* MiniMook: They resemble the Nihilanth in many ways, but according to the Nihilanth himself, they're not of the same species. They look like hybrids of Nihilanth and vortigaunt, so maybe they're an artificial crossbreed species.
* MookLieutenant: According to Laidlaw, the Controllers are basically conduits for the Nihilanth's psychic control of the Vortigaunts, and as a result are the highest ranked "generic" aliens on Xen.
* MultiArmedAndDangerous: Just like the Nihilanth, Vortigaunts, and Alien Grunts.
* MyBrainIsBig: Their Head:Body ratio is even higher than the Nihilanth's
* PowerFloats: They float around rather quickly, making them hard to hit with several weapons.
* PsychicPowers: Similar to the Nihilanth, though much less powerful.
* ShockAndAwe: Via ball lightning, unlike the Vortigaunts' charged beam.
[[/folder]]

[[folder:Houndeyes]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/houndeye.jpg]]
Tripedal pack hunters. Houndeyes work with their fellow packmates to overwhelm attackers with violent sonic-attacks, showing levels of coordination and intelligence not unlike Earthly canine species. Especially notable is their massive clusters of eyes that cover the front half of their body.
-----
* BizarreAlienBiology: They sport 3 legs and a "face" comprised of a cluster of eyes under a single giant eyelid. Their mouths are found on its belly, beneath the eyes.
* BlownAcrossTheRoom: An active hazard when fighting Houndeyes, as their attack can chuck a player a couple feet.
* ColorCodedForYourConvenience: A Houndeye's sonic-boom attack varies in damage depending on the color of the blast. Teal means it's at its weakest, while violet means its at its strongest. Damage is influenced by the presence of a pack leader and how many pack members are supporting it, as explained in [[https://www.youtube.com/watch?v=Lqxag2TDqtQ&list=PLDmcwfn8y0lMtlqcpUhggk0FB1EC2i3iB&index=54&t=0s this video.]]
* ConservationOfNinjitsu: Inverted; a Houndeye's shockwave attack ''strengthens'' when more Houndeyes are nearby and part of its pack.
* FantasticFaunaCounterpart: They act like pack wolves despite being from another world/dimension, and even make some sounds that sound similar to dog whimpering/barking.
* MakeMeWannaShout: When a Houndeye is preparing to attack, they'll start howling ''very'' loudly while charging their sonic-boom before blasting their target.
* TakingYouWithMe: Unintentional on the Houndeye's part, but due to the indiscriminate nature of their sonic boom attacks they're incredibly dangerous to fight in close quarters whenever explosives are involved. If a Houndeye is howling next to an explosive crate in front of you, you'd better have a quick aim or dive out the way, because it's going to splatter both itself and whatever's near it in a few seconds.
[[/folder]]

[[folder:Bullsquid]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/bullsquid.png]]
Highly aggressive, durable and predatory alien creatures that sport a muscular build and a tentacled face, named after their agitated bull-like attitude and squid-physique as a result.
-----
* BerserkButton: Bullsquids are programmed to attack headcrabs first, no matter who is in their sight.
* BizarreAlienBiology: They only sport two legs, have a carnivorous cephalopod mouth, are camouflaged similarly to leopards, and can spit out globs of corrosive spit at prey.
* LightningBruiser: Relatively quick, and are noticeably more sturdy than most of other Xen wildlife as well as having some lethal attacks to their name. Fortunately they tend to stand still or charge directly at the player, so hitting them isn't usually too hard.
* MixAndMatchCritters: Names aside, they have traits of cephalopod, leopard-print skin and what looks like an amphibious nature.
* NoodleIncident: A Bullsquid is apparently responsible for Eli Vance's missing leg. The implication is that one ate his leg, but the exact circumstances aren't quite known.
[[/folder]]

[[folder:Alien Aircraft]]
[[quoteright:230:https://static.tvtropes.org/pmwiki/pub/images/alien_aircraft_9639.jpg]]
Strange flying alien creatures seen being used by the Nihilanth's forces during their invasion of Earth.
----
* AmbiguousRobots: Similar to the Gargantua, it's unknown what the dividing line between their armaments and their bodies is.
* AirborneMook: They're the only form of aerial forces seen being used by the Nihilanth's forces.
* {{BFG}}: The powerful energy weapon they have built into their bellies, which in various scripted sequences is seen doing stuff like disintegrating rather thick rock formations and reducing an Osprey to scrap in less than a second of sustained fire.
* DeathFromAbove: Averted; they'll never attack targets on the ground.
* FinalBoss: One is the final boss of ''Decay''.
* FlyingSeafoodSpecial: Hence why they're commonly called "Manta Rays" by fans.
* GentleGiant: When encountered on Xen, they're completely harmless, and are pretty much the only moving thing that ''[=won't=]'' attack you. On Earth, however, they act as a dropship for the Xenian forces and directly attack HECU aircraft.
* LightningBruiser: Can take as much damage as a tank and fly at speeds that at least exceed Mach 1, as evidenced by the shock waves they create.
* MadeOfIron: You only actually fight one once, at the end of ''Decay''. It takes as much damage as a tank to put down, though that may just be its FinalBoss-ness in action.
* NaturalWeapon: A laser-like weapon built into their belly that they can fire downward. It bears some resemblance to the weapon used by Combine Gunships when spawned by the console.
* TeleportersAndTransporters: They appear to have a teleporter built into their bellies, allowing them to drop alien soldiers from Xen.
[[/folder]]

[[folder:Tentacle]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/tentacle_9.jpg]]
Tentacles are the appendages of an even larger and ravenous alien creature, buried beneath the ground. Said tentacles are shaped like scythes and are constantly prodding the ground around them for prey to drag down into the burrow to be EatenAlive. Due to their burrowing nature, the creature primarily hunts through touch, sound and especially vibrations.
-----
* AchillesHeel: Grenades and explosive charges, though not because they can damage it. The creature can't see and relies on ground vibrations to find prey, so chucking a grenade across the room or setting up some charges to explode will fool it into aggressively attack the blast-site to no avail, and lets Gordon sneak away unharmed.
* BarrierBustingBlow: The first introduction to the Tentacle is when its appendage smashes through a control booth to grab an unfortunate scientist who caught its attention into its maw.
* CombatTentacles: They're literally called Tentacles and they can rip Gordon up just by stabbing him with their bladed tips.
* DegradedBoss: The first Tentacle fought is a BeefGate that Gordon spends the level trying to destroy and bypass, because it's directly in the way out of the rocket silo. More Tentacles are encountered on Xen, but in much more navigable circumstances, and sometimes while missing some of their appendages.
* EatenAlive: The fate of anything caught by the tentacles.
* {{Kaiju}}: The tentacles already tower over most enemies like a two-story building, but the long fall down into the burrow indicates it to be more or less a kaiju in size.
* KillItWithFire: The first ever Tentacle encountered happened to have burrowed itself beneath a space rocket. Naturally, it meets its end when Gordon fires up the rocket thrusters to utterly incinerate it.
* SinisterScythe: The Tentacles' blades are shaped like scythes, except they're bigger and more effective at killing than actual scythes.
[[/folder]]

[[folder:Snark]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/snark_v_hd.jpg]]
[[caption-width-right:350:A Snark equipped as a weapon.]]
The Snark, also known as the Squeak Grenade, are small, beetle-like creatures with four legs, a single green eye, and a thick, dark red, segmented shell and a tendecy to explode after attaking because of this they can be used as a biological weapon. It can be found in Snark Mines / Snark Nests, and will attack the player when the mines are tripped. However, the nests can be picked up and snarks can be used as weapons that can be thrown towards enemies.
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* ActionBomb: After a minute of frenzy they explode on their target.
* AttackAnimal: In ''Half Life 1'' and its expansion packs, Snarks are used as live grenades that home onto enemies, [[HoistByHisOwnPetard although they can also attack their wielder]] if said wielder isn't careful.
* TheBusCameBack: After being absent from the series since ''Decay'', Alyx has a pet Snark in ''VideoGame/HalfLifeAlyx''.
[[/folder]]

[[folder:Ichthyosaur]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/ichthyosaur.jpg]]
The Ichthyosaur ("Spined Alien Fish Beast") is an aquatic alien species transported to Earth from Xen During the Resonance Cascade.
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* TheCameo: It's not a normal enemy in ''Half-Life 2'', and is only seen when it nearly attacks Gordon in a lake during the TeleporterAccident near the beginning of the game.
* NonIndicativeName: It's named after the extinct marine reptile group but looks like a mix of a tiger, a [[VideoGame/{{Starcraft}} Hydralisk]], and a piranha.
[[/folder]]

[[folder:Leeches]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/leech_attack.jpg]]
--> "I, eh, hope you like leeches."
-->-- The Fisherman (''Half-Life 2: Lost Coast'')
Leeches are small, pale white aquatic alien lifeforms who swarm water sources to quickly overwhelm and consume all prey encountered.
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* AlienKudzu: They're dangerously common on Earth, and they've rendered most sea life [[ExtinctInTheFuture extinct]] or endangered by eating them all during their stay.
* ArtEvolution: In the original game, they looked like a hybrid between a leech and a fish. Meanwhile in the sequel, they look more like eels by comparison.
* BorderPatrol: Having overwhelmed the ocean life, Leeches are practically the only things encountered in beach water anymore in ''2''. They'll swarm and kill Gordon if he's too deep in the water.
* DeathOfAThousandCuts: They're not particularly damaging, but they tend to show up in great enough numbers that they're a threat when Gordon needs to swim underwater in the submerged parts of Black Mesa. In ''2'', they're encountered when Gordon tries to swim too far into the ocean, and will eventually bite him to death if he doesn't get out.
* DemotedToExtra: In the original game, they used to be actual [=NPCs=]. But in ''2'', they're just a damaging entity [[BorderPatrol to prevent the player from going too far into the water or]] [[StayOnThePath bypassing the path]].
* FromNobodyToNightmare: They went to the weakest enemy in their debut to an actual threat to the ocean life in the sequel.
* TheGoomba: In ''1'', where they used to be far weaker than the Headcrabs.
[[/folder]]

[[folder:Jeff]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/jeff_1_0.png]]
A [[{{Mutant}} formerly human combine worker]] who stalks a derelict and spore infested distillery. He's completely blind, but sports perfect hearing to compensate.
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* ArcVillain: Of Chapter 7 in ''Alyx'', which is aptly [[AntagonistTitle named after him]]. He's the primary threat Alyx must avoid as she navigates the vodka distillery.
* BodyHorror: His split human head revealing two sets of teeth, which is now shaped like a Venus Fly Trap, is only the tip of the iceberg for Jeff's condition, to say nothing of the massive, spore spewing boils on the rest of his body.
* FluffyTheTerrible: One of the most horrific monsters in the game, and he's simply known as ''Jeff''.
* HandicappedBadass: Jeff will absolutely rip you to shreds if he can find you, but his blindness makes evading him relatively easy... as long as you are careful around bottles and spore clouds, of which there are ''several'' in the vodka distillery he inhabits.
* ImmuneToBullets: Jeff is so heavily mutated that ''nothing'' Alyx can carry will hurt him. [[spoiler:The trash compactor, on the other hand, will do just fine.]]
* IncrediblyLamePun: ''Near-Jeff Experience'', the achievement for staying right next to him for 10 seconds.
* InvincibleMinorMinion: Jeff is flat out immune to any of the weapons that Alyx can carry, making stealth a priority when around him. [[spoiler:After you trap him in the trash compactor, though, you can kill him by just turning the machine on]].
* LudicrousGibs: Reduces several headcrabs into this. [[spoiler:He himself will become an example if you activate the trash compactor while he's in it]].
* OurZombiesAreDifferent: Rather than being the series standard definition of a zombie with their headcrab, Jeff seems to be a person who was overwhelmed and mutated by Xen spores.
* SingleSpecimenSpecies: For whatever reason, nothing remotely like him as been seen at any point prior in the franchise.
* SuperSenses: His hearing is so precise that he'll zero in on the location of the noise to investigate and attack whatever made it. This can also be used against him, as throwing objects across the room as a distraction keeps him busy for a little while.
* TragicMonster: He was once a completely normal human before his horrific and painful mutation.
* WasOnceAMan: Once a human worker at a vodka distillery, before he was heavily mutated into the blind monstrosity Alyx faces in Chapter 7.
* ZombiePukeAttack: His primary form of attack is to start throwing up a torrent of caustic blood from his maw.
[[/folder]]

!!The Combine
[[folder:In General]]
[[quoteright:256:https://static.tvtropes.org/pmwiki/pub/images/combine_poster.png]]
A powerful trans-dimensional alien empire, they conquered the Earth and are the main antagonists of ''Half-Life 2'' and its Episodes, as well as ''Half-Life: Alyx''. Their occupation force on Earth, the Overwatch, consists of a portion of their transhuman forces (modified humans using human vehicles and weapons) and "Synths", aliens who have been modified and outfitted with cyborg attachments and pulse weaponry. Think [[TabletopGame/Warhammer40000 The Imperium of Man]], but more cyberpunk and with less ambiguity of their evilness.
----
* AchillesHeel: The Combine are an impossibly vast inter-stellar and possibly ''trans-dimensional'' empire of massive size and scope. They have advanced technology, competent tactical ability, ruthless efficiency, and a track record for not being trifled with. At the same time, much like the real-life Roman Empire, their massive size causes all sorts of bureaucratic kerfuffles and makes actually ''mobilizing'' that immense power difficult to say the least. Thus, the Combine forces on Earth are cut off from the main bulk of the empire's military forces and it is only through the Citadel that they are able to maintain a decently sized militia. [[spoiler:Once the Citadel blows up, it's revealed the reason they're so interested in Earth is that we discovered true long-distance teleportation technology at both Black Mesa and Aperture Science. The Combine have no such technology and must slowly drive their fleets across the universe in real-time, which makes long distance travel too much of a resource dump to actually justify doing. However, if they could harvest that portal technology they would be able to move their forces around the universe in a blink of an eye, making them effectively unstoppable. Unfortunately for them, the destruction of the Citadel and the closing of the Portal Storm above its ruins means that the remaining Combine forces on Earth are stranded with no backup, and considering the Citadel also doubled as their only way to communicate with their off-word command center, it's safe to say that humanity actually has a fighting chance against the Combine forces still remaining on Earth.]]
* AirstripOne: The remaining cities under their control on Earth are simply given numerical designations, with ''Half-Life 2'' and its episodes being set in "City 17," located somewhere in Eastern Europe.
* AliensAreBastards: Oh boy, where to ''start?'' Completely unprovoked and imperialistic conquest of an entire species (one of '''millions''' no less)? Check. Using [[PuppeteerParasite headcrabs]] as biological weapons to inflict a [[AndIMustScream horrifying fate]] on anyone who gets overtaken by one? Check. Ruthless lobotomization and forced cybernetic augmentation to their army of transhuman [[SlaveMook slave soldiers]]? Check. A literal "beating quota" for Civil Protection officers? Check. Indiscriminate slaughter of unarmed humans [[UndergroundRailroad attempting to escape City 17 or help others do so]]? Check. Turning any [[LaResistance resistance members]] they capture into [[FateWorseThanDeath cybernetic slaves stripped of their humanity]] [[BodyHorror and most of their organs]]? Check. [[GaiasLament Steadily stripping the Earth of all its usable resources, up to and including the oceans]]? Check. [[DeathWorld Permanent off world relocation]] as a [[BadBoss punishment]] for [[YouHaveFailedMe failure?]] Check. Setting up a suppression field to [[ChildlessDystopia prevent all human reproduction, thus guaranteeing extinction within a century?]] Check. Honestly, the Combine could have codified the trope.
* AliensNeverInventedTheWheel: A fantastical variant. The Combine are an incredibly advanced multi-dimensional empire that effortlessly conquered the Earth and likely millions of other worlds, but they apparently never discovered a method for short-range teleportation within a single dimension, something which humans managed to invent at least twice.
* AmbiguousRobots: It's unclear whether some Synths are actually alien species enslaved and heavily augmented for military purposes by the Combine, or are just robots manufactured by Combine with some biological characteristics.
* ArtificialBrilliance: ''None'' of the Combine forces are stupid. First off, the Overwatch soldiers will flank, throw grenades, and run to cover when reloading. Furthermore, the Hunters will use splash damage, flank, and lay down suppression fire. Also, the Gunships will wildly strafe while firing, and will even shoot down your missiles in mid-air. However, they ''do'' fight very aggressively, meaning that once you've figured out their tactics, it's fairly easy to fall back and ambush them. Furthermore, Combine foot-soldiers do not have a high amount of hit points, and so will usually get killed by the player before their strategies can kick in. And this trope is mostly averted by Civil Protection soldiers, who tend to stand in place firing away with pistols, which makes sense when you consider that they're really closer to being beat cops rather than soldiers.
* AuthorityEqualsAsskicking: The Combine Advisors are the top tier in the Combine hierarchy, or at least very close to it. They have the authority to subsume any Combine forces they need, and sacrifice them without a second thought. While they resemble blind limbless grubs the size of baby elephants, they have powerful [[MindOverMatter telekinetic]] and [[MindRape telepathic]] abilities, and are able to completely immobilize and control anyone around them, as well as levitate themselves for transport. They are also MadeOfIron. You actually briefly get a chance to shoot at one during the first stage of the assault at White Forest, using a mounted pulse cannon, which seems to be the Combine's equivalent to a .50 machine gun. Despite taking many shots, only a few of which are enough to kill PoweredArmor wearing cyborgs, the Advisor shows no visible signs of injury and escapes unharmed. This also shows the limits of their powers; the Advisor can't actually throw Freeman around like the previous ones did, only being able to give him a headache, likely because of the (not at all long) distance between them.
* BadassArmy: Well, they don't call it the "Seven Hour War" for ''nothing''...
* BigBad: Of the second game and subsequent episodes.
* CreativeSterility: For all their advanced technology, the Combine Empire appears to be unable to create something that is truly their own, original design. Every bit of their technology and utilities appears to have conceived by violently appropriating an already existing design from another race and then building upon, or rather twisting it until it serves the purpose they need it for.
* CripplingOverspecialization: Despite having sophisticated technology for teleporting between alternative realities, this technology only seems to be found in the Citadel and some other small locations across the globe. Furthermore, it doesn't seem to be that efficient for transporting large groups of units at once (as seen during the climax of ''Half-Life 2'' with how long it takes to just teleport Dr. Breen to the Combine Overworld), with it being all but stated that the Combine's regular access to Earth after the Portal Storms abated became very fragile. And their technology for achieving teleportation ''within'' the same reality is downright laughable, with Black Mesa, Aperture Science, and even the Resistance having the kind of tech the Combine could only ''dream'' of.
* CurbStompBattle: The entire might of every military on Earth combined was utterly destroyed by them in just ''[[TheShortWar seven hours]]''.
* {{Cyborg}}: Synths are part mechanical, part biological aliens that Combine enslaved at some point and turned into military machines by forcibly augmenting them with advanced cybernetics. Transhuman Overwatch and Stalkers are the latest examples in this trend, showcasing Combine's true intentions for what they are going to do with humanity.
** [[AllThereInTheManual According to]] ''The Final Hours of Half-Life: Alyx'', synths are [[MeaningfulName synthetic]] copies of animals scanned by the Combine, instead of simply organic aliens converted into cyborgs. Concept art exists of [[https://combineoverwiki.net/wiki/File:Hla_combine_concept_6.jpg a Combine soldier riding a horse-synth]]. This raises the question of why Overwatch isn't the same -- [[EpilepticTrees is it something Breen negotiated, forcing the Combine to keep a living human population?]]
* DeadlyEuphemism: Apparently as part of protocol, the Metrocops, Soldiers and even the [[VoiceWithAnInternetConnection Overwatch]] [[CannedOrdersOverLoudspeaker Announcer]] use medical jargon Newspeak to communicate. Alien intruders are "exogens", zombies are "necrotics", turrets are "sterilizers", soldiers are "stabilization delegates", Freeman, as Anticitizen One, is "malignant" and [[OhCrap contact with him]] is a "staph infection". Troops are also routinely issued orders like "inoculate", "shield", "clamp" and "cauterize".
* TheEmpire: Most fictional empires would be satisfied with taking over the world or, at most, the galaxy. The Combine instead conquered ''the entire universe''. But then, even ''that'' wasn't enough, so they made portals to other universes and proceeded to conquer them too.
* TheEndOfTheWorldAsWeKnowIt: After the fall of City 17, the Union is ''pissed'', and this is said to happen if the forces on Earth manage to ever call the rest of their empire for reinforcements.
-->'''Isaac Kleiner''': What you're seeing is the infancy of a superportal. If it attains full strength --
-->'''Eli Vance''': [[OhCrap It'll be the Seven Hour War all over again.]] [[FromBadToWorse Except this time, we won't last seven minutes.]]
* EvilLearnsOfOutsideContext:
** After the Resonance Cascade event accidentally opens a portal between the Earth and the alien world of Xen, this alerts the Combine (who had enslaved the species inhabiting Xen) of Earth's existence. After an extremely brief "war", the Combine conquer Earth and add it to their collection of enslaved worlds. Twenty years later, a similar problem threatens to happen: the Combine have mostly turned their attentions away from Earth to allow their local puppet (Dr. Breen) to rule, but Breen warns that the insurrection started by Gordon Freeman might make the Combine start paying ''direct'' attention to the Earth, which would not go well for anyone. Even after Breen is defeated, portal storms start occurring over Earth, only making it more likely that a huge Combine force will arrive to put down any further sedition.
** Obscure details within the game lore reveal that this trope actually makes Earth ''extremely'' important to the Combine's plans. Despite their massive multiversal empire, the Combine fall into the same trap that most massive empires do: being much too large to effectively rule. Although they are capable of using portals to travel from world to world, this ''only'' transitions them between dimensions and ''not'' space. However, Earth scientists were on the cusp of discovering interspatial teleportation that, if perfected, could allow the Combine to mobilize their entire fleets anywhere within their massive empire at any time. This was the bargaining chip that [[TheQuisling Dr. Breen]] used to convince the Combine that Earthlings were valuable, but should the Combine gain such technology, then they would effectively be unstoppable.
* {{Expy}}:
** Generally speaking, they're one of Ingsoc and Oceania from ''Literature/NineteenEightyFour'', only [[RecycledInSpace with aliens]]. This was even more visible in the Beta, which looks astoundingly similar aesthetically to the 1984 film adaptation.
** Their [[TripodTerror Striders]] are heavily based after the Tripods from ''Literature/TheWarOfTheWorlds.''
* FascistButInefficient: ''Shockingly'' so. Despite being an empire that spans ''multiple universes'', encompassing countless galaxies, planets, and ''millions'' of different species, the Combine [[CripplingOverspecialization forgot to invest anything in worthwhile teleportation technology]]. Their travel methods are slow and inefficient considering the massive span of their empire, and their teleportation system, while functional, is actually ''less advanced'' than what both Black Mesa and Aperture Science have designed.
** It '''really''' can't be overstated how awful this is for them. It's explained that they can only efficiently teleport ''between'' dimensions, not within a single dimension. Whether or not they have some sort of space fleet for travel is unknown, but what is known is that the destruction of the Citadel crippled their forces on Earth, as it not only knocked out their only source of transit to/from Earth and cost them their biggest base, it also resulted in their distress signal to their empire proper getting intercepted by the Resistance. This is why in ''Episode Two'' the Combine, especially the Advisors, become ''very'' desperate to obtain the Black Mesa teleportation technology so they can contact their headquarters for reinforcements. You'd think a reliable method of teleporting among your galaxies upon galaxies of controlled territory would be one of the first things a multi-dimensional empire would develop.
* {{Foreshadowing}}: At the very least, something ''much'' nastier than the Xenians was hinted at by the Nihilanth way back in the first game.
-->'''Nihilanth''': Their slaves... we are their slaves... we are...
* GasMaskMooks: Justified, in that Overwatch Transhuman troops are in use on other, non-human-habitable planets.
** Apparently, the Civil Protection officers just wear them because it looks intimidating. Also Justified as [[TruthInTelevision this is something SWAT teams do in real life.]] Besides, given how brutal the metrocops are, it's probably best they remain faceless and anonymous.
* GreaterScopeVillain: Of the first game. Also in ''Half-Life 2'', while Breen acts as the BigBad, the Advisors are clearly above him and are seemingly the Combine's leaders.
* {{Hypocrite}}: They, through their PuppetKing Breen, actively propogate the idea that instinct makes people fear the unknown, see it as a threat. Ironically, the Combine themselves [[NotSoAboveItAll deem Freeman a threat]] the second he sets foot in City 17 simply because he's an unknown miscounted citizen.
* InsectoidAliens: The land Synths look like insectoids, while aircraft Synths look more like cetaceans or [[GiantEnemyCrab crustaceans]]. Made of metal. [[MoreDakka With guns]].
* InsignificantLittleBluePlanet: It's clear that they don't care at ''all'' about Earth or humanity, considering the token force they've left to occupy it (with the majority of even the transhuman forces being used elsewhere) and the [[CrapsackWorld state of the planet]] after they're done draining it for resources. They've conquered millions of species, the humans are just one more to them.
** On the other hand, once they learn that the Rebels have developed simple and cheap teleportation (compared to the Combine teleporters at least), the Combine becomes ''immensely'' more interested in their activities. And after City 17 falls, they ''immediately'' stop underestimating the Rebels, and waste no time making preparations to call ''a massive assault on Earth with reinforcements from the Union's Home Universe itself.''
* {{Leitmotif}}: [[invoked]] [[https://www.youtube.com/watch?v=DUh8pyCmEwM "Combine Harvester"]], though sadly not used in the games. It's MusicToInvadePolandTo mixed with haunting alien noises.
* LesCollaborateurs: The Civil Protection members are humans who willingly decided to work with the Combine. It is implied that while at least some of the volunteers have somewhat sympathetic motives for joining up, such as better food and housing, many of them have done it simply for the power and brutality they are allowed to exercise.
* LoadBearingBoss: A collective, in-story version. For all the Combine's cruelty, they at least did manage to keep the massive Antlion infestations in check and keep headcrabs out of their cities. But then Gordon Freeman blew up Nova Prospekt, destroyed their defensive network of machine gun bunkers and 'thumpers' on the coast (thereby letting the Antlions into Nova Prospekt), slaughtered hundreds of soldiers and Synths, started a worldwide rebellion, and blew up the Citadel. All these things caused the Combine to lose control over City 17, resulting in a massive invasion by the nearby Antlion colonies and an infestation of headcrab zombies. By the time ''Episode One'' begins, the entire region is caught in a [[MeleeATrois four-way struggle]] between the headcrab zombies, the antlion hordes, the Resistance, and the Combine.
* MillionMookMarch: Upon exiting Victory Mine in ''Episode Two'', you get a clear view of a distant bridge where surviving Combine forces from City 17 are all marching together to regroup with other survivors. Transhuman soldiers, Striders, Gunships/Dropships, and City Scanners travel together escorting their rescued Advisor commanders, who are still in their escape pods.
* MiniBoss: Gunships and Striders.
* MechaMooks: The Earth Overwatch seems rather understaffed (likely due to most of the transhuman forces being shipped off-world), so make use of units like automated turrets, scanner drones, and Manhacks to make up for it.
* MultiversalConqueror: According to [[invoked]] WordOfGod, the Combine have already conquered several universes, enslaving their home species and forcibly modifying them for use as Synths. They're in the process of doing the same thing to Earth.
* NiceJobFixingItVillain: When Gordon Freeman goes through their weapon confiscator field in the Citadel, it destroys all his weapons except the Gravity Gun, which the confiscator instead makes more powerful, powerful enough to kill Combine soldiers with a simple trigger, pick up energy balls from a distance, and eventually destroying the Citadel's dark energy core.
* NormalFishInATinyPond: With a side of OutsideContextProblem. As described under FascistButInefficient the Combine are quite capeable of staging interdimensional invasions but are actually quite poor at mooving troops and resources around within a dimension itself. While the exact mechanics of determining and controlling the relationship between interdimensional teleportation locations with relevance to physical dimension locations[[labelnote:Note]] i.e. How easy is it for the Combine to open portals to other parts of the same universe? Could they open a portal on Mars for example? Could they open a portal on the other side of our universe?[[/labelnote]] goes unexplained, it's possible that the Combine have only amassed the overwhelming resource and technological dominance that they have by invading individual resource-rich planets accross dimensions. For all we know given thier difficulty moving resources and troops over long distances within dimensions they may not even dominate their home universe.
* OrganicTechnology: The Synth units. They were originally living animals or people until the Combine invade them, converting them into bio-mechanical weapons. In fact, the Combine gunship serves as that trope's current page image.
* OverarchingVillain: they are the BigBad of the second game and the GreaterScopeVillain of the first game.
* PlanetLooters: It's very clear that the Combine have ''no'' long-term plans for Earth. They're visibly just taking every resource they can use, including the ''oceans'', atmosphere, and some population, and shipping it off-world.
* PoliceBrutality: Civil Protection; some of their terror-mongering acts include beating people for no reason, shooting people after they surrender and lining up innocent people on walls and using them for target practice in true Nazi-Gestapo-meets-Soviet-NKVD style. Think of them as a worldwide example of the StanfordPrisonExperiment.
* PuttingOnTheReich: The Civil Protection and Overwatch uniforms were based on [[CommieNazis both Soviet and Nazi designs.]] This was more blatant in the original concept art.
* TheSingularity: The Advisors have passed it, a ''very'' long time ago, according to [[invoked]] WordOfGod.
* ShoutOut:
** [[invoked]] WordOfGod has stated that the main inspiration for the Combine's [[PoliceBrutality "Civil Protection"]] organization was that of [[https://en.wikipedia.org/wiki/Stanford_prison_experiment the Stanford Prison Experiment]].
** The Combine as a whole are heavily inspired by the hallucinations of Chief Bromden from ''Literature/OneFlewOverTheCuckoosNest.''
* SlaveMooks: An entire army of them, with most of the Combine soldiers you fight throughout ''Half-Life 2'' and its episodes are actually cybernetically modified and enslaved transhumans. Also, the "Striders," "Gunships," "Hunters," "Dropships," and "Synth Scanners" you see in-game are all either enslaved aliens or biomachines. It's [[invoked]] [[WordOfGod implied]] that there are ''millions'' of enslaved species. The Vortigaunts ''may'' have been one of them, though they were later found to be enslaved by the Nihilanth. In fact, the Nihilanth's species' role in relation to the Combine is never really explained, and neither is Race X's role.
* SociopathicSoldier: Surprisingly, ''not'' the Overwatch. They're just brainwashed slaves who tend to kill their targets while being mostly stoic. No, the ''real'' sociopaths here are in Civil Protection, mentioned above in PoliceBrutality; the corps consists of humans who joined the Combine's forces willingly, for perks like extra rations and sexual privileges. They appear to be somewhere between SWAT police and low-ranking soldiers. Their tasks are basically to instill fear in every citizen, and to brutally crack down on small resistance pockets. Their technology is notably a bit more primitive, as well. Where the Overwatch and Airwatch use Striders, Gunships and energy weapons, CP units make do with [=APCs=], patrol helicopters, and submachine guns.
* SufficientlyAdvancedAliens: They curb-stomped the combined military might of every country on Earth in just seven hours. It took Dr. Breen to convince them not to ''exterminate'' every single human and settle for enslaving us instead.
* SuicidalOverconfidence: Part of their official policy. Any Overwatch soldier who fails and lives to report about it will receive "[[ReassignedToAntarctica permanent off-world assignment]]". Their destination is likely not pleasant.
* VestigialEmpire: Not the Union itself, but its occupation of Earth is quite low in maintenance. Some of their own structures appear to be rusting, and most of their much stronger Synth army was withdrawn in favor of human occupation forces long ago. While the rest of the Union thrives, it's made evident they don't care much about Earth or its integrity.
* VillainBall: Downplayed, but their usage of headcrab shells on Resistance locations, since it only replaces still-dangerous-but-manageable human Resistance fighters with uncontrollable hordes of Zombies that can be a ''lot'' more unpredictable and difficult to manage than the Resistance itself.
* WhiteMaskOfDoom: The Metropolice, although the Combine Elites are even worse.
[[/folder]]

[[folder:Shu'ulathoi/Advisors]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/combine_advisor.jpg]]
Rhino-sized, grub-like alien lifeforms. They led the Universal Union's Synth invasion of Earth, and now command the Combine forces stationed on Earth through Breen and the Overwatch, taking direct control in ''Episode 2''. The Vortigaunts are familiar with the Advisors, whom they call "Shu'ulathoi", having long been enslaved by them. They are ancient beings, extremely intelligent and powerful, possessing a variety of psychic and telekinetic abilities.
----
* AliensAreBastards: Our FirstContact resulted in them enslaving us and exterminating much of the population. At the end of the day, they are just here to extract our resources and ship it back home.
* AlienInvasion: They led the Combine in their invasion of Earth, conquering the planet in only seven hours.
* AliensSpeakingEnglish: They can fluently communicate via telepathy in what seems to be a variety of languages.
* AmbiguousSituation: Their name: it's unclear if they're the rulers of the Combine and are "advisors" to Breen's puppet government, or if they're lower-ranking advisors to something even more powerful.
* AncientAstronauts: Though they never ''technically'' visited Earth, according to [[invoked]] WordOfGod they had been closely observing Earth for a very, very long time before they invaded. Not for us humans, but [[PlanetLooters for our natural resources]].
* AssimilationPlot: Every race the Combine conquers is either forcibly or willingly assimilated into their unified ranks. After Breen convinced the Advisors to not annihilate humanity, this has become their main goal.
* AuthorityEqualsAsskicking: It's unknown where exactly they fall in the Combine hierarchy, but Dr. Breen is completely subservient to them, as are all Combine-affiliated forces on Earth by extension. They're armed with extraordinarily powerful psychic abilities and end up directly commanding all of the Combine military force left on Earth by ''Episode Two''.
* BigBad: At the very least they oversaw the Combine invasion of Earth, and later rule over its occupation from clandestine stasis pods.
* BlobMonster: Other than their long tongues, they have no discernible body features, appearing like a mass of grey flesh, resembling grubs.
* {{Cyborg}}: Apparently they aren't adapted to Earth's atmosphere (not ''yet'', anyway) and as such are outfitted with a wide variety of odd mechanical apparatus. Additionally word of god states whatever the Advisors once were they hit the technological singularity a long time ago and achieved their species equivalent of widespread transhumanism. It shows.
* EvilColonialist: Their entire motif is conquering then assimilating and/or enslaving all species they come across, or simply plundering their worlds for resources.
* EvilOverlord: Unclear how high in the overall Combine rankings they are, but they are the overseers of the Combine occupation of Earth.
* {{Expy}}: They're based on the Guild Navigators from ''Literature/{{Dune}}''.
* FatBastard: Whether they're naturally this fat or it's the result of their modifications, the Advisors are nonetheless diabolical aliens who are [[GreaterScopeVillain behind the Combine invasions]]. The way they kill their prey by ''[[MindProbe eating the victim's brain with their long tongue]]'' while trapping said victim with PsychicPowers is deeply unsettling.
* TheGhost: Their existence isn't known by anyone on Earth outside of the Combine's highest ranks and the oldest Vortigaunts; not even the folks of Black Mesa knew what they were. By ''Episode Two'', it's revealed that Breen was little more than a puppet for their interests.
* GreaterScopeVillain: Revealed in ''Episode Two'' to actually be the ones who were in charge all along, not Breen.
* KarmaHoudini: At the end of ''Episode Two'', [[spoiler:the Advisor [[HeroKiller who killed Eli Vance]] does get a swift beating from [=D0G=], but it nonetheless survives and escapes with the other Advisor, leaving the game on a [[DownerEnding depressing]] CliffHanger with Gordon slowly losing his consciousness while watching Alyx Vance grieving over her dead father. Thankfully in ''VideoGame/HalfLifeAlyx'', this very same Advisor gets ''[[KarmaHoudiniWarranty killed]]'' by Alyx herself, thanks to the use of RealityWarper powers from [[DealWithTheDevil a deal]] with the G-Man himself.]]
* KillAllHumans: At first they wanted to wipe out the human race ''entirely'', viewing us as [[HumansAreInsects insects not even worth ruling over]]. Only through Breen's pleading did they reconsider this and settle for enslavement.
* {{Leitmotif}}: [[https://www.youtube.com/watch?v=D3d1cpWmL5U Plays alongside them, named after them.]]
** [[https://www.youtube.com/watch?v=DUh8pyCmEwM This even incorporates some of their own synthetic vocal noises, as if they're singing along.]]
* LogicalWeakness: They are incredibly powerful psionics, but Dog is able to absolutely tune one up the moment he gets his hands on it; he's a robot - their mind-altering abilities don't affect him, meaning it's a floating bug versus a furious robotic gorilla.
* MarsNeedsWater: One reason they invaded Earth, it seems, was to siphon our oceans.
* MasterRace: Often believed that they are the masterminds of the entire Universal Union, or at least part of the leading race.
* MindProbe: Their long tongues allow them to pierce through humans easily; [[invoked]] WordOfGod suggests they can literally suck out human brains in order to interpret their knowledge and their memories, making it especially vital that Resistance leaders don't fall into their clutches. [[spoiler:Given that one of them seemingly ate Eli's brain at the end of ''Episode 2'', it's probably a good thing that Alyx diverts that timeline in her game.]]
* PsychicPowers: Telekinesis, Clairvoyance, Telepathy, Empathy.
** MindRape: Either through their vocal noises or through mind powers, they can induce debilitating, severely painful seizure-like effects on anything in their close proximity.
*** The graphic and sound effects used on-screen when an Advisor is in close proximity gives a very realistic portrayal of what it's like to have a migraine. Don't get migraines? Now you know what it looks and sounds like to those who do.
* RealityWarper: Not on the same level as the G-Man, but they are capable of freezing time and space in a short area, and can manipulate this localized area at will.
* ReluctantRuler: For unknown reasons the Advisors remain in stasis up until ''Episode Two'', very rarely asserting control over Earth themselves and leaving most of it up to Breen. By ''Two'', however, they take direct control with a vengeance.
** Justified by meta-explanations of canon - The years that Earth had been under their rule, they were merely there to observe and not intervene, part of Breen's obligation to prove to them that humanity was worth sparing and integrating into the Universal Union rather than eradicating outright.
* SquishyWizard: They have strong psychic attacks, but they're easily dispatched in a physical fight by Dog, and can even be taken out by conventional fire.
* SuperIntelligence: As some of the oldest beings in existence, they've got the intellect, accumulated knowledge, and the administrative skills to control, or at least aid in running, an empire that stretches across multiple ''dimensions''. It's even implied that they mastered universal space travel at the same time as humanity was still in its Prehistoric era.
* StarfishAliens: They resemble rhino-sized brain-sucking grubs with no eyes, arms, legs or face. The [[invoked]] [[WordOfGod developers]] deliberately wanted to invoke the image of a species that passed its [[TheSingularity Singularity]] a ''very'' long time ago. They rely on mechanical arms and eyes for manipulation and anti-gravity packs for movement. Well, those and their [[GameBreaker near-unstoppable]] [[PsychicPowers telekinetic]] and [[MindRape telepathic]] abilities.
* TheWorfEffect: [[spoiler:At the end of ''Half-Life: Alyx'', all the G-Man has to do is buff Alyx's gauntlets a bit with some of what appears to be his own power, and that is enough for her to ''absolutely toast'' the Advisor that aimed to kill Eli, with the Advisor never even realizing what was happening before dying. Super-intelligent as they are, even these beings are utterly vulnerable against whatever the hell the G-Man is]].
* YouHaveFailedMe: After Breen's consistent failures against the Resistance and Freeman, it's made clear they no longer have any use for him.
[[/folder]]

[[folder:Dr. Wallace Breen]]
[[quoteright:189:https://static.tvtropes.org/pmwiki/pub/images/brn_9315.png]]
-> Voice Actor: Creator/RobertCulp (English)[[note]]'''Other Languages''':Nikita Prozorovsky (Russian)[[/note]]
->''"How about it, Dr. Freeman? Did you realize your contract was open to the highest bidder?"''
Breen is the earlier head of the Black Mesa Research Facility, and was unnamed and unseen in the first game, where he is merely referred to as "The Administrator". In ''Half-Life 2'', he is the main antagonist and the Combine's puppet ruler of Earth, a position he got after selling out mankind to them.
----
* ZeroPercentApprovalRating: Given that he's TheQuisling for [[AliensAreBastards The Combine]] and it's heavily implied that he's really in this just for the power, pretty much no one outside of the Combine's own forces like him.
* AntiVillain: Zigzagged. On one hand, he appears to genuinely believe his own propaganda about the Combine, and his surrender of Earth that he orchestrated might have saved humanity from total extermination, even if the new regime reduced the remaining population to slaves. On the other hand, however, it's implied he's in it purely for himself. It's very possible he ''knows'' what he's saying is lies, but he holds onto the idea that it might be true because he knows the alternative is even worse, having completely lost hope in humanity.
* AssholeVictim: While it's unclear if he actually dies at the end, either way it's hard to feel sorry for him.
* BeardOfEvil: Interestingly, it's rather similar to Gordon's beard.
* BigBadWannabe: While he is the main antagonist of ''Half-Life 2'', he is just being used as a puppet by the Combine Advisors (who are the real main antagonists) and is shown to be a DirtyCoward when faced by Gordon.
* BitchInSheepsClothing: While he superficially seems like a ReasonableAuthorityFigure he is actually helping the Combine to wipe out the human race (he actively advocates for the use of a device that prevents humans from breeding, which he claims will help them focus on other things, in reality it's a plot to make people stop reproducing so they go extinct).
* BodyHorror: In the original ''Half-Life 2'' script, Breen himself was going to be turned into an Advisor. (In fact, the last conversation Breen has with an Advisor has him complaining there's no way he could survive Combine space, and apparently gets a psychic answer, because he then reacts incredulously that the Advisors have a less-than-pleasant way for him to live.)
* BondVillainStupidity: When he flees to the portal after talking to the Advisor, he [[WhatAnIdiot forgets to take the supercharged Gravity Gun with him]].
* BreakingSpeech: He's quite found of these such as near the end of ''[=HL=]2''.
--> '''Breen''': I'd like to take a moment to address you directly, Dr. Freeman. Yes, I'm talking to you. The so-called One Free Man. I have a question for you. How could you have thrown it all away? It staggers the mind. A man of science, with the ability to sway reactionary and fearful minds toward the truth choosing instead to embark on a path of ignorance and decay. Make no mistake, Dr. Freeman. This is not a scientific revolution you have sparked... this is death and finality. You have plunged humanity into freefall. Even if you offered your surrender now, I cannot guarantee that our benefactors would accept it. At the moment, I fear they have begun to look upon even me with suspicion. So much for serving as humanity's representative. Help me win back their trust, Dr. Freeman. Surrender while you still can. Help ensure that humanity's trust in you is not misguided. Do what is right, Dr. Freeman. Serve mankind.
* CorruptCorporateExecutive: He was the administrator of Black Mesa before becoming the Combine governor of the Earth, and pushed for the risky analysis that eventually led to the disaster in the first game.
* DirtyCoward: He begs Freeman to surrender to the Combine [[spoiler:and attempts to escape him by teleporting away from Earth.]] Not helped by the fact that he essentially sold all of mankind's freedom to the Combine (admittedly because otherwise, the Combine would have completely erased humanity from Earth, but still) so he could sit comfortably at the top of the [[EvilTowerOfOminousness Citadel]] and wants to avoid all kinds of direct confrontation.
* EstablishingCharacterMoment: His first appearance on the monitors. While he may [[FauxAffablyEvil sound like a kindly ruler, his rhetoric is decidedly authoritarian]], befitting his status as an {{Expy}} of [[Literature/NineteenEightyFour Big Brother]].
* EvilOverlord: Of City 17.
* FauxAffablyEvil: Breen's pretty well spoken and (mostly) calm for being a smug backstabber. But he's also cold, dismissive, patronizing, arrogant, smarmy and passive-aggressive. Though he often covers it with a veneer of concern, friendliness, and approachability — especially in his Breencasts — the underlying disdain and indifference, even towards his allies, is unmistakeable.
* {{Foil}}: In a lot of respects, he serves this to Gordon: both are bearded scientists who worked at Black Mesa and had a prominent role in the catastrophe, but contrasting a HeroicMime who proves his worth through action with a NonActionBigBad whose primary role is his endless bloviation. Both are also pawns of a larger power with little meaningful agency who are upheld as figureheads by the populace — making Breen's fervently loyal yet empty and miserable servitude of the Combine into something of a possible future for Gordon.
* TheGhost: In the first game, he's just referred to as "The Administrator" a couple of times.
* GodzillaThreshold: Gordon Freeman's mere arrival forces Breen to cross this. While he knew of the rebel cells and was waiting for the opportunity to clean them up once and for all, Freeman's appearance in his office (which also gives away that the rebel have working teleporation, a big deal to the Combine) forces Breen's hand because he ''knows'' that the OneManArmy theoretical physicist being allowed to gallivant around freely could undermine everything he's worked for. Going all-out with the Combine Overwatch captures Eli and strikes the rebels before they were ready - [[SelfFulfillingProphecy but drives Freeman into the perfect circumstances to incite a world-wide rebellion and come for Breen.]]
* HateSink: Breen is good at holding public speeches, but they underly his deceitfulness. Otherwise he lacks any sympathetic, likable or even cool qualities, and apart from being a ruthless dictator, he is shown to be little more than an incredibly smug, condescending, cowardly asshole who is slowly wiping out humanity on the behalf of alien invaders for the sake of personal power.
* HumansAreTheRealMonsters: In a series all about fighting evil aliens, one of '''the''' most vile and dangerous enemies of all ''is a human.''
* {{Hypocrite}}: In his Breencasts he says that "small minds" use the term "the Combine", and ostensibly eschews that label in favor of "Our Benefactors" and "the Universal Union." However, when you meet him in person he ''himself'' calls them "the Combine."
* IDidWhatIHadToDo: Breen rationalizes his actions on the grounds that The Combine were going to simply exterminate humanity in its entirety to take earth's resources and what technology we had invented. Dr. Breen convinced them to spare humanity on the condition we proved ourselves worthy of being assimilated. At least on paper his actions make sense but in the process he secure a comfortable position of power for himself and proceeded to lord it over the remains of humanity, effectively ignoring the fact that we were still condemned to extinction by the suppression field. He may have saved humanity but for his own sake rather then humanity as a whole.
* MisanthropeSupreme: His motivations are a wee bit unclear. He ''did'' convince [[TheJuggernaut The Combine]] to enslave rather than outright exterminate humanity (and was afterwards named Administrator of Earth), but whether he did so for personal power, or because he really cared about humanity is left unclear.
* {{Narcissist}}: He's got propaganda posters of himself in City 17 and even busts of himself in some locations — including ''his own office''. Then there's the fact he's got jumbo screens of himself talking plastered all over the place.
* NeverFoundTheBody: We never really know what happened to him after the end of ''2'' when The Citadel is destroyed. Considering the massive explosion and teleportation link to Combine territory, it's a coin toss between him being utterly obliterated in the blasts epicenter, or being stranded in parts unknown in one form or another.
* NiceJobFixingItVillain: He takes the Gravity Gun with him to escape, frees the heroes by accidentally triggering it, and leaves it on the floor before Alyx and Gordon catches up to him, allowing Gordon to take it back and defeat Breen. Granted, he probably never really knew to operate it, and he was clearly wasn't able to hold it with the same sort of ease as Gordon, so he might've just tried a hail mary play and abandoned it because he believed it would slow him down and he didn't realize Gordon could use it to ruin his escape plan.
* NonActionBigBad: The final battle is against him, but it's the other soldiers and the gunships who are attacking you.
* PuppetKing: Over all of humanity due to the Combine.
* TheQuisling: He refers to a genocidal race that owns a big chunk of the multiverse as "Our Benefactors", at least when speaking over the Breencasts.
* SesquipedalianLoquaciousness: Mildly. He's very eloquent and likes to use fancy or obscure synonyms for common words. It's like he reads thesauruses in his spare time.
* SmugSnake: Things escalate beyond his control rather quickly. He also gloats about being able to effectively demand ''anything he wants'' from the Combine in exchange for handing over Eli, but while it is true that Eli's knowledge of how to achieve local teleportation would be very valuable for the Combine, "anything I want" is probably a tad presumptuous against an unfathomably powerful multversal empire that could just march in and ''take'' Eli if they really wanted to.
* SophisticatedAsHell: His speech is normally impeccably erudite, so it makes [[PrecisionFStrike the one time he swears]] ''glorious''.
* UncertainDoom: [[spoiler:At the end of ''Half-Life 2'', the platform lifting him up the teleporter collapses, and he seems to fall to his death. In ''Episode One'', a recording of Breen conversing with an Advisor suggests he may have become (or had a copy of his mind transferred into) an Advisor.]]
* VillainousBreakdown: He becomes increasingly impatient and childish as Gordon Freeman kills off his soldiers and starts a rebellion. When Gordon invades the Citadel, Breen goes from first trying browbeating him into surrendering, to frantically, but still condescendingly trying to reason with him, and finally he starts outright begging for him to stop. Later, while trying to escape via teleport, he resorts to juvenile taunting and mockery — then goes back to begging when it becomes clear that Gordon's not playing around.
* WellIntentionedExtremist: Judging by the events of the Seven Hour War, he managed to stave off extinction. It was either death or AFateWorseThanDeath for all of humanity, and so chose the latter. Breen might honestly believe that the Combine will elevate humanity to the next level, though he has turned a blind eye to TranshumanTreachery by the Combine, and his behavior behind closed doors suggests that he may be in this purely for the power.
* WickedCultured: He shows a mild example of SesquipedalianLoquaciousness, and makes reference to advanced physics notions several times, but we're not sure exactly what his MorallyAmbiguousDoctorate is actually ''in''. In any case, everything about him, from his way of speaking to his bearing and his dress, screams "scholarly and cultured".[[/folder]]

[[folder:The "Shadow Scientist"]]
-> Voiced by: Creator/KimDickens (''Half-Life: Alyx'')
->''"We need to move the box or this thing is going to be Black Mesa all over again."''
A mysterious figure glimpsed in ''Half Life: Alyx'' working with the Combine.
----
* TheFaceless: The player never sees her directly, only her shadow cast on the wall. The only way to see her actual model is through datamining.
* GenreSavvy: She is actively trying to convince the Combine to move the Vault when Alyx overhears her conversation, as she believes that would be much more effective to move it to a more secure location than try to stop Alyx directly, as she thinks the soldiers guarding it won't be able to stop her. [[CassandraTruth She's right]].
* ISeeThemToo: [[spoiler:One of the few characters revealed to have knowledge of the G-Man.]]
* TheQuisling: Whoever she is, it's clear from her brief appearance that she's a Combine sympathizer. However, she also seems to enjoy a great deal of autonomy — she describes herself as being her own boss, is cleared to know about the Vault and its contents despite being an unaltered human and the Combine’s obsession with keeping it secret, and can talk down to ''Advisors'' without repercussions.
* SmallRoleBigImpact: Unintentionally, her conversation with the Advisor is what causes the protagonists to [[spoiler:think that the Vault contains Gordon Freeman.]]
* SuspiciouslySimilarSubstitute: As a defector working with the Combine, she plays a very similar role to Judith Mossman, to the point of many players making the assumption that she is indeed Mossman. [[https://twitter.com/ValveNewsNetwor/status/1245883467541426177?s=20 Datamining has revealed that she isn't Mossman.]]
[[/folder]]

[[folder:Overwatch Voice]]
-> Voice Actress: Creator/EllenMcLain (English)[[note]]'''Other Languages''':Natalia Radskaya (''Half-Life 2''), Olga Kuznetsova (''Episode One''), Zhanna Nikonova (''Episode Two'') (Russian)[[/note]]
->''"Attention ground units. Anticitizen reported in this community. Code: [[DeadlyEuphemism lock, cauterize, stabilize]].''"
The other voice of the Combine, outside of the Breencasts. The voice is a feminine AI who spouts propaganda and announcements to the public, and delivers orders to the Civil Protection and Overwatch troops.
----
* AccentUponTheWrongSyllable: Initially she speaks like this, due to being an AI who is likely going through automated messages. By the time of ''Episode Two'' she's dropped this in favor of a [[ColdHam cold and perfectly pronounced dialect.]]
* CannedOrdersOverLoudspeaker: For either Combine propaganda or to relay tactical information to ground units. Somehow the Combine doesn't care that Gordon Freeman and LaResistance can hear them.
* DeadlyEuphemism: Many of her brutal orders are given in medical terms, and are echoed by the troops she commands. To name a few:
** Amputate: Kill.
** Sterilizers: Sentry guns.
** Cauterize: Secure the area, kill all targets.
** Infection: Anti-civil activity.
** Verdict(s): Civil Protection punishments.
** Extractors: Grenades.
** Terminal/Capital Prosecution: [[JudgeJuryAndExecutioner On-the-spot death sentencing by Civil Protection teams.]]
** Sacrifice-Coagulate-Clamp: Code for all units to enact a ZergRush.
* DissonantSerenity: City 17 can be exploding all around her, which is exactly what ends up happening by the time Gordon returns, and yet she'll still coldly and methodically be sending out orders to the troops.
* DisproportionateRetribution: While Freeman is escaping City 17 through its city blocks and eventually the UndergroundRailroad, she's heard ordering Civil Protection teams to exterminate all civilians in the block. Later, she's heard announcing that another blocks ration supply, which is presumably already the bare minimum, is being reduced even further. Both of these were for their inaction in trying to capture Freeman.
* TheDragon: While Breen is a figurehead for the human populace and the Advisors pull the strings from behind the scenes, the Overwatch AI seems to have the majority of control over the police and military might on Earth and even significant control over civilian rights, and as such seems to operate separately but still in conjunction with the Advisors. When the Citadel explodes, the remaining Combine make the effort to salvage and repair her to help rally scattered forces, meaning she's definitely of high enough priority for the Combine to be 'rescued'.
* EmotionlessGirl: Her voice is feminine, and she simply spouts the Combine's orders and propaganda matter-of-factly.
* LeaveNoSurvivors: She gives the order to 'de-service' all prisoners in Freeman's area when he breaches Nova Prospekt to prevent them from meeting. You can find possible evidence of this when you reach a prison cell where a dead Vortigaunt was strapped to a chair and apparently executed.
* MissionControl: For the Combine.
* MissionControlIsOffItsMeds: In ''Episode One'', it's clear that the heavy damage to the Citadel has done a number on her. Her voice is slowed down and generally buggy and she is seemingly out of touch with the situation, with the orders she gives to stabilize the reactor core being ignored by the soldiers. In ''Episode Two'' her voice is more stable, but even colder and more imposing, implying she was repaired by and is now under direct control of the Advisors.
* NicknamingTheEnemy: The Overwatch has given a variety of codenames to threats to the Combine rule, most, if not all in medical jargon.
** Parasites/Necrotics: Headcrabs and Zombies.
** Viromes: Antlions.
** Outbreaks/Malignants: Rebels.
** Vance Subprime: Alyx Vance. Eli Vance is presumably Vance Prime.
** Anticitizen One/Staph Infection: Gordon Freeman.
* NominalImportance: She's pretty much ''never'' referred to or acknowledged by any characters aside from Combine units reporting things into their radio to her and rarely characters reacting to her voice as a sign of incoming Combine, but she's still heard throughout the game relaying tactical info and helps provide context to how the Combine military operates and what's it like living under Combine rule.
* PreMortemOneLiner: While Gordon is still being chased by the Civil Protection, she may make it a point to directly refer to him via the officer's radio when he's close to death.
--> Attention: Freeman. Prepare for final sentencing.
--> Attention: Freeman, you are charged with terminal violations 143, 243, 245. All protection team units: complete sentencing at will.
* RobotGirl: She's clearly an AI, and talks in a feminine, cold, clinical voice.
* VoiceWithAnInternetConnection: Is present in City 17, Nova Prospekt and in the Citadel to give orders to Civil Protection and Overwatch units.
[[/folder]]

[[folder:Civil Protection]]
-> Voiced by: Kelly Bailey
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/cp_8.jpg]]
--> [[AC: Pick up that can.]]
--> A Civil Protection officer [[EstablishingCharacterMoment trying to bully Freeman minutes after his arrival.]]
The Combine's excessively violent police force, which consists of humans who have joined the Combine willingly for all the benefits it will get them.
----
* ArtificialStupidity: Downplayed, but when compared to the Overwatch troops AKA an actual military force, Civil Protection tactics are about as basic as standing a healthy distance away and firing their guns without many other tactical maneuvers. Justified, in that they're essentially police officers and not trained military.
* DroneDeployer: Some of them pack Manhacks on themselves, and will activate and toss them in the air to hunt targets down for them.
* GasMaskMooks: They wear particularly bulky gas masks, and unlike the Overwatch military, they don't seem to serve any tactical or life preserving purpose other than keeping the officer anonymous and intimidating to civilians.
* IHaveYourWife: After killing Freeman, one of the messages the overwatch voice can notify to the Civil Protection soldiers is that their "family cohesion has been preserved", implying that many of them are working under the threat of being separated from their families entirely if they fail at completing the task.
* PoliceBrutality: They're well known for their especially violent and bullying nature, whether on command from the Overwatch AI or just for their own amusement.
* PunchClockVillain: Many citizens end up joining Civil Protection for the bonuses that come with it, ranging from ration rewards, family safety, somewhat better living conditions, and possibly non-simulated sexual gratification. As such they show much more humanity than the lobotomized and brainwashed Overwatch troopers.
* RadioVoice: Their voices are especially garbled and deep thanks to their helmets, likely to either keep their communications hard to understand to non-CP units, and also just as likely to keep them anonymous.
* SuperPersistentPredator: Throughout much of the ride in the airboat in ''Water Hazard'', a CP attack helicopter is constantly ahead of you, trying to bomb and gun you to death no matter how many tunnels and detours you take. It isn't until the boat's armed with a cannon that it's able to be taken out, and even then the pilot is determined to die trying to kill you in the final confrontation.
* TanksForNothing: Not battle tanks, but the Civil Protection apparently have access to [=APCs=] armed with guided missiles, and are more than happy to deploy a street's worth of them to kill Freeman. Not that it does them any good, as they're very easy to outmaneuver and speed past.
* WhiteMaskOfDoom: Played with, as their gas masks are pale white and they terrorize citizens daily. To any sufficiently armed Resistance member, and especially [[OneManArmy Freeman]], they're only rarely as dangerous the Combines formal military forces.
[[/folder]]

[[folder:Combine Overwatch]]
-> Voiced by: Kelly Bailey
The Transhuman Arm of the Combine Overwatch represents the Combine's military infantry forces on Earth. They are much better trained and equipped than Civil Protection, and unlike them are not merely [[BlackShirt Black Shirts]], but fully cybernetically converted post-human soldiers remade in the Combine's image.
-----
* ArtificialBrilliance: They flank, throw grenades, use cover while reloading, move in squads, and fire while moving and slicing around corners, but due to their relatively low health compared to the player, they tend to die before they can employ any real impressive degree of strategy.
* BadassBaritone / EvilSoundsDeep: The Overwatch soldiers speak this way by design.
* BodyHorror: ''Half Life: Alyx'' seems to show they're essentially sealed inside their suits, to the point that if the helmet is removed their flesh retains the shape of its indentation. Their eyes have also been removed to allow for a direct connection between their helmet optics and their brain.
* BoringButPractical: Outside of their obviously advanced pulse weapons and cyborg-vehicles (which even then are equipped besides mundane firearms and regular vehicles), most of the Combine body armor is fairly mundane and padded kevlar, with the odd equipment out being their advanced helmets.
* ColorCodedForYourConvenience: The regular soldiers are colored gray and blue, and are relatively average combatants. The Shotgun Soldiers, on the other hand, are brown and red and more dangerous. And then there's the Combine Elite (though his model is separate), who is white with touches of black and is the most dangerous.
* CyberCyclops: The Combine Elites have a single red eye in the front of their helmets.
* CyberneticsEatYourSoul: The military forces of the Combine have been largely outfitted with tons of cybernetics done through invasive surgery, with the head being a frequent target of operation by removing the eyes to allow for direct interface with their helmet optics, or outright cleaving everything except the brain away to basically make their helmet their new head. Outside Combine soldiers are hardly emotive outside of being surprised, with the most heard out of them is a uncharacteristically panicked ''''Shit!'''' if their sniper's nest had a grenade tossed into it, or shouting ''''Outbreak'''' into their radio if their squad's been wiped out.
* EliteMooks: The Combine Elites. They have better aim, take more damage before dying, are always equipped with assault rifles, and utilize their assault rifle's undermounted energy ball launcher. Plus they show up much later in the game.
* EyeScream: Implied with the Combine Elites due to their singular red eyes. You can see an undressed Combine Soldier with several cybernetic implants in Nova Prospect. This can make you wonder how the Elites look beneath their helmets... or not.
* FakeUltimateMook: The Combine Overwatch may look big and scary, but the untrained ragtag rebels are actually better shots (strangely this only applies to SMG's, Rebels and Combine soldiers are on par in accuracy with the other weapons). Still, the Overwatch soldiers are actually more effective in combat though because of their ability to throw grenades and their slightly larger amount of health. Justified in that, despite their augmentations, they're less [[SuperSoldier Super Soldiers]] and more mass-produced disposable Mooks.
* GasMaskMooks: Justified, in that Overwatch Transhuman troops are in use on other, non-human-habitable planets.
* HeavilyArmoredMook: Seen with the introduction of Combine Suppressors and Combine Chargers in ''Half Life: Alyx'', having significantly heavier armor compared to standard Combine Grunts, and fulfill very standard Heavy roles in combat; the Suppressor pins you down with heavy automatic weapons fire while relying on his armor to protect him due to him not being able to use cover, while the Charger charges you position with a shotgun.
* ReassignedToAntarctica: Transfer to a permanent off-world position is apparently one of the punishments for failure that are meted out to Overwatch soldiers that displease Breen or the Advisors.
* StandardSciFiArmy: The Combine Overwatch is a well-organized military that makes use of specialized units. The Transhuman Arm is the ''General Infantry'', consisting of the basic soldiers and make up the primary bulk of the Combine's forces on Earth. Synths are a combination of ''Artificial Biologicals'', ''Armor'', and ''Aircraft''.
** Combine soldiers act as the ''Line'' infantry, being the most commonly encountered Overwatch soldier and are armed with a variety of weapons such as pulse rifles, [=SMGs=], and shotguns.
** Nova Prospekt prison guards are a combination of ''Line'' and ''Security'', being a variant of the Combine soldier assigned to guard Nova Prospekt.
** Combine Elites serve as ''Elite'' and ''Praetorian'', being the Combine's most elite transhuman soldiers armed with powerful weapons and show up late-game. They also have a distinctive appearance from the other Overwatch soldiers and are shown acting as bodyguards for the Combine's leaders.
** Overwatch Snipers are ''Special Ops'', often working alone and pick off their enemies one-by-one with their high-powered sniper rifles.
** Stalkers are a mix of ''Logistical'' and ''Engineers''. They act as the Combine's support units, handling the menial work in the Citadel and are responsible for repairing and maintaining the Combine's vehicles.
** Combine Grunts are a mix of ''Light'' and ''Line'' infantry. They are the Combine's most commonly encountered unit in ''Half-Life Alyx'' but are not as mechanically modified compared to the typical Combine soldier. They are also more lightly armed, using solely [=SMGs=] as their primary weapon, and are more lightly armored.
** Combine Ordinals are ''Elite''. They use an early version of the pulse rifle and are better armored than the Grunts. They are shown acting squad leaders for teams of Grunts.
** Combine Chargers and Suppressors both act as the ''Heavy'' infantry. Chargers are a [[MightyGlacier heavily armored and slow]] mook who tanks damage, uses an energy shield to block gunfire, and wields a powerful shotgun in combat. Suppressors are also heavily armored and use a mini-gun to pin down Alyx and enable the Grunts to flank her.
** Civil Protection is ''Security'', being the Combine's civilian police force charged with controlling the populace and enforcing the Combine's rule over Earth's populace.
* UndeathlyPallor: In some points of the the series, you can see what an unarmored Overwatch soldier looks like. In ''Half-Life 2'', they're deathly pale white with cybernetic insertions on their body, presumably they're in the process of being given their armor.
** In ''Alyx'', you can examine a soldier without his faceplate. [[https://i.imgur.com/gOXNbDr.png They're also deathly pale]], but now have [[FacialHorror patterned imprints strewed across their face, their skull seems indented from wearing their helmets]] and [[EyeScream their eyes have been scooped out to directly connect their optic nerves to their helmets.]] That, or their eyes were directly connected to their helmet before it got pulled off.
* WeWillWearArmorInTheFuture: Averted with the transhuman Overwatch soldiers, who wear kevlar-like soft armor that resembles modern riot gear with what look likes protective inserts, in contrast to the more standard [=sci-fi=] plate armor with ShouldersOfDoom that most FPS soldier enemies tend to wear.
[[/folder]]

[[folder:Stalkers]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/stalker_0.jpg]]
->''"This is what happens to you if you resist...or if you're just in the wrong place at the wrong time."''
->[[OOCIsSeriousBusiness Alyx upon seeing a Stalker]].
Stalkers are the haphazardly and torturously made cyborgs who the Combine use for menial labor and as maintenance crews for their structures. They're typically created from citizens and rebels judged guilty of disobedient behavior and who were unfortunate enough to be caught alive before being hauled away for augmentation.
-----
* AndIMustScream: If the Stalker's weren't lobotomized and rendered to their base instincts, and they still retained their memories of their past selves, then they're living a conscience existence of working in a Combine structure whilst sporting a surgically mangled body that effectively makes them the even more unwilling slaves of the Combine. [[https://youtu.be/ipYOMnTwulo?t=95 They also do tend to scream a lot when disturbed.]]
* BodyHorror: Stalkers have been starved to the bone, had much of their inner organs removed, had the ends of their limbs amputated, their [[GroinAttack groin severed/burnt into a flat surface]] and they sport various implants around their body. Note that this is used as a punishment than any real practical purpose.
* TheDreaded: Various major characters like Alyx and Kleiner make allusions and implications to what awaits anyone who gets caught and taken alive by the Combine, implying some FateWorseThanDeath. Stalkers are what they're talking about, and Alyx is horrified when she sees one face-to-face.
* EyeBeams: Their face plates can fire a heat ray. It's actually meant for maintenance work, but they'll decide to use it if they detect any troublesome intruders.
* FullFrontalAssault: They're wearing nothing but their cybernetics on them, [[BodyHorror not even their groin.]]
* HellIsThatNoise: Their loud scream, notorious if you've ever played any sort of horror themed fan map. It's heard twice in Half-Life 2 and once in Episode One.
* MundaneUtility: Played with. With all the technological might the Combine sport and their expertise in drone technology, both cyborg and autonomous, they could easily build and program other means of maintenance crews. But instead, they create Stalkers out of disobedient civilians as a punishment, [[MakeAnExampleOfThem an example to others]] and a little bit of cruel pragmatism. In any case though, Stalkers are still effective at their assigned purpose.
* NothingButSkinAndBones: Likely from starvation and being fed the bare minimum needed to live and work.
[[/folder]]

[[folder:Hunter-Chopper]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/hunter_chopper_canals_6.jpg]]
A rotorcraft re-engineered by the Combine to support the Overwatch forces with heavy fire and the deploying of contact mines.
----
* DegradedBoss: You fight another Hunter-Chopper in ''Episode 2'', but this one doesn't TurnsRed after receiving enough damage and you can defeat it simply by using the gravity gun to throw its mines back to it without the need of heavy weaponry.
* LightningBruiser: Since it's an armored helicopter, the Hunter-Chopper is fast and mobile, has tough armor that can only be damaged by its own weapons (and even then it takes a while to take it down), and carries a deadly arsenal of weaponry, such as a [[MoreDakka pulse cannon]] and [[StuffBlowingUp contact mines]].
* RecurringBoss: In ''Half Life 2'', the Hunter-Chopper is a continuous threat through the "Route Kanal" and "Water Hazards" chapters, forcing you to take cover constantly to avoid its heavy fire without being able to properly counter-attack. You finally confront it with your own pulse cannon near the end of later chapter.
* SuperPersistentPredator: The fact that no other Hunter-Chopper appears after destroying one near the end of "Water Hazards" suggests that it's been the same aircraft chasing you down all along.
* TurnsRed: In its final confrontation near the end of "Water Hazards", the Hunter-Chopper sounds an alarm and starts carpet-bombing the battlefield.
* UniqueEnemy: It's the closest thing the base ''Half Life 2'' game has to a unique boss, as you only encounter one of it, with it chasing you through multiple levels until you finally acquire the weaponry needed to confront and kill it.
[[/folder]]

[[folder:Strider]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/patrolling_strider.jpg]]
Striders are towering, tripedal Combine war machines whose armored body is held up by three spindly legs. They're armed with rapid-fire pulse cannons, and can occasionally fire a devastating blast from their warp cannon.
-----
* {{Cyborg}}: Keeping in theme with the Combine military, Striders are some kind of alien crustaceans that were forcibly repurposed into serving the Combine. It's unknown how far the cybernetics go, with only their naturally armored exoskeleton and their cannons being visible.
* DegradedBoss: In ''Half Life 2'', ''Episode One'' and ''Alyx'', Striders are faced as straight-up boss battles, requiring the player ration out rocket supplies, dance around the Striders attacks and to keep in mind where the ammo crates are. In the finale of ''Episode 2'', several of them show up at once in a mass rush to destroy the Resistance rocket, and the player is expected to take them all out in time. This is made possible thanks to the Magnusson Device, which can kill them instantly provided the bomb connects.
* TheDreaded: The Rebels are reasonably terrified of fighting Striders, who tend to take more than a couple rockets to bring down and can easily level buildings. They're positively amazed when Gordon Freeman shows up and does much of the work needed to kill one for them.
* HellIsThatNoise: Their [[https://www.youtube.com/watch?v=_KUaeyXP3Tw presence]] is announced from ground-shaking stomps and long, drawn out moans over the sound of gunfire. In ''Half Life Alyx'', Striders now make [[DroneOfDread drone-like]] [[https://www.youtube.com/watch?v=0BLd1DGb3mw noises]] that are comparable to the Reapers from ''VideoGame/MassEffect'', or the Cybertronians from the ''Film/TransformersFilmSeries''.
* ImpaledWithExtremePrejudice: Thanks to their long spiky legs, Striders can impale unfortunate Resistance members who get too close and shake off their skewered corpses, just like how one would scrape off a piece of gum on their shoes.
* MightyGlacier: Due to their massive height and awkward gait, Striders are initially slow-moving, and their size makes them easy-to-hit targets. On the other hand, Striders have tough [[ImmuneToBullets bullet-proof]] armor that requires five rockets to kill them on Easy mode (seven on Normal mode and above)[[note]]As a reference, the toughest enemy vehicles in the first game could be taken down with just three rockets[[/note]], pulse cannons that [[MoreDakka fire hailstorms of bullets]], and deadly warp cannons that can [[ArmorPiercingAttack ignore cover]]. As for their speed, Striders can be ''[[LightningBruiser incredibly fast]]'' if they need to, such as crawling in tight spaces. Regardless of their strengths, Striders can be instantly killed with the Magnusson Device in ''Episode Two'', so long as the bomb connects to the main body and is detonated manually.
* MoreDakka: Their pulse cannons fire in rapid bursts and they seemingly have a limitless amount of ammunition.
* MundaneUtility: In ''Alyx'', the Combine workforce are shown using unarmed “construction” Striders to help them establish powerlines around town more quickly, namely by riding on their backs like living work-lifts.
* OffWithHisHead: For a given definition of 'head', but a Strider who engaged in a fight with DOG had its brain ripped out of its head when the raging robot managed to hop on its back.
* PhallicWeapon: Gabe Newell noted that they were designed by a young art intern, who wanted them to have a penis as their main weapon to intimidate and unease players. Newell used the design on the spot.[[note]]Considering Gronarch is basically a giant testicle, Valve is fairly used to using H.R. Giger-like sexual imagery.[[/note]]
* TripodTerror: Crustaceous machine gun totting cyborg tripod terrors, who are just as willing to use their armored legs to kick and stab their enemies with as much as they are for shooting them.
[[/folder]]

[[folder:Gunship]]
[[quoteright:300:https://static.tvtropes.org/pmwiki/pub/images/gunship.jpg]]
Combine Gunships are flying war machines who provide air support to ground units through strafing runs that hail an overwhelming amount of gunfire from their pulse cannons.
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* ArtificialBrilliance: When fighting, they'll make wild movements in the air to avoid attacks while trying to keep aim at their targets. If a rocket is homing on in them and they're not either distracted or caught vulnerable, they'll divert their attention to either shoot down the projectile or take evasive maneuvers.
* {{Cyborg}}: They're another crustaceous alien creature that likely swam in the waters of its own world before being captured and repurposed as flying gunners. At this point, it looks like only its exoskeleton and eyes remain (which are found on its sides) past all the machinery and guns.
* HellIsThatNoise: They tend to roar and moan very loudly over the sound of their propellers. [[https://www.youtube.com/watch?v=Oae9btXTXm4 Listen here]].
* MiniBoss: Similar to the Striders, they're pretty much always encountered as a massive obstacle that needs tons of firepower to bring down. The game is usually generous with the amount of rocket ammunition sitting around to help with this, though that often means having to run through the rain of fire to restock.
* MoreDakka: Their guns sport a ludicrously high fire rate, always fired in long bursts that forces its targets to take cover.
[[/folder]]

[[folder:Hunter]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/hunter_43.jpg]]
Hunters are tripedal alien cyborgs that were first found in the forests surrounding City 17. They're fought as pack hunters who try to stalk and ambush their targets with superior numbers and agility, with their primary weapon being an explosive flechette launcher.
-----
* AchillesHeel: They have high damage resistance to most weapons (they take 60% damage from bullets and 50% damage from shotguns), but are vulnerable to physics damage and being hit with their own flechettes. They also don't resist magnum rounds or explosives, and can be killed instantly by the pulse rifle's energy orb alt-fire.
* {{Cyborg}}: Just like the other synths, Hunters are alien creatures that have been modified with cybernetics for the sake of combat.
* EarlyBirdCameo: A Hunter was first seen in ''Episode 1'', as part of a Combine attack on a Resistance base, where it busts through a wall and smashed the camera. They wouldn't be fought as proper enemies until ''Episode 2''.
* HoistByHisOwnPetard: Equip the Gravity Gun, shield yourself with a suitably large object from their flechette attack, and launch it back at them to deal huge damage with their own projectiles. There's an achievement for doing this.
* LightningBruiser: These guys are incredibly fast and sneaky. [[{{Pun}} Combine]] those qualities with super tough armor and deadly explosive flechettes, and you got a deadly living weapon that also comes in packs.
* {{Sadist}}: ImpliedTrope. Along with their purpose of ruthlessly pursuing Resistance members, Hunters make a [[EvilLaugh sinister]] [[https://youtu.be/eDqhw04BjWc?t=52 giggle]] whenever Gordon's health is low. The possibility of this trope is all the more horrifying when Hunters are [[ItCanThink more than just animalistic weapons]], they take pleasure in hunting down their terrified prey.
* StuffBlowingUp: Their flechettes will explode for a while upon impact. [[HoistByHisOwnPetard However]], their flechettes can be used against them if Gordon throws a flechette-covered object at them with his Gravity Gun.
* TripodTerror: Similar but smaller when compared to the Striders, but they make up for it in speed, numbers and stealth capabilities.
[[/folder]]

!!Other Antagonists
[[folder:HECU]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/fb7374f79c39ade1b75bbbbb5a66ea82.jpg]]
-> Voiced by: Kelly Bailey, Mike Shapiro and Harry Robins (''Half-Life 1'')
-> Jon St. John (''Half-Life: Opposing Force'')
->''"[[BadassBoast We will kick your ass]]!"''
->''"Government cover-ups were ''not'' [[NotWhatISignedUpFor in my job description]]."''
The Hazardous Environment Combat Unit is a special forces unit who was sent to Black Mesa to clear up the aliens, it is soon discovered that they are also under orders to silence all the Black Mesa personnel... with bullets. They end up having to pull out, leaving behind dozens of their own troops in the process, while the Black Ops took over the operation.
----
* AchillesHeel: The Marines in the original ''Half Life'' and its expansions [[DoNotRunWithAGun couldn't move and shoot at the same time]], so they were vulnerable when repositioning or coming around corners, though they normally had a squad providing covering fire for them when they advance to compensate for this.
* AntiVillain: The more noble ones are this. They are trying to thwart an alien invasion, and they are willing to stay behind and die just to kill as many of them as they can. Many of them strongly disagree with killing the staff and only do so because they are afraid of being executed themselves. It's not hard to sympathize with some of them.
* AntiHero: The ones featured in ''Opposing Force'' are this. While they still treat the scientists and security guards harshly, their more redeeming features are emphasized, namely their determination to fight their way out of Black Mesa, killing any more Xen or Race X Aliens invading the facility, and their loyalty to one another.
* ArmiesAreEvil: ZigZaggedTrope. On one hand, many of them remorselessly massacre unsuspecting Black Mesa personnel. Others, however, openly question as to why they're engaging unarmed civilians as opposed to dealing with the aliens, and by the time they pull out of Black Mesa, are more concerned with getting out the facility together.
* ArtificialBrilliance: They were praised as being the first tactically intelligent enemies in video games. They regularly throw grenades, take cover, and work as a squad to attack from multiple angles.
* ArtisticLicenseMilitary:
** The HECU medical personnel are referred to, both in-universe and out, as medics. The U.S. Marines, which make up the HECU's foot soldiers, do not use medics. They have [[InsistentTerminology corpsmen]], who are actually from the Navy and have been specially trained to work and fight alongside the Marines.
** Although they're identified as marines, HECU soldiers deploy various types of military hardware that are not used by U.S. Marines in real life, including U.S. Army's M2 Bradley [=IFVs=] (real-world marines use LAV-25) and AH-64 Apache helicopters (real-world marines use AH-1W Super Cobras), as well as U.S. Air Force F-16 fighters (real-world marines use AV-8B Harrier [=II=] fighters). Their individual equipment also ranges from heavily outdated (such as using the [=Mk2=] Grenade, which had been replaced by the ''1960's'') to never fielded by a real-world military force (such as the [[HandCannon Desert Eagle]]). A [[WatsonianVersusDoylist Watsonian approach]] might justify this, since - as noted elsewhere on this page - the HECU may actually be a multi-branch effort that pulls equipment on its own terms, while a [[WatsonianVersusDoylist Doylist explanation]] is that they are Marines because [[SemperFi Marines means they are more elite]].
** Played with in their individual uniforms, the HECU uses a white-and-grey camouflage with a black vest. While the US Military never used that kind of uniform [[note]]At the time the game was made, they used the [[https://en.wikipedia.org/wiki/U.S._Woodland M81 Woodland]] or the [[https://en.wikipedia.org/wiki/Desert_Camouflage_Uniform Three-colour desert]][[/note]], this gear was a protype developed in the 90s for urban warfare program called [[https://66.media.tumblr.com/0c4d2cd86fab7915df487ad47160658b/tumblr_plgqev3qbK1rt826bo6_540.jpg Operation Urban Warrior]], showing that Valve [[ShownTheirWork did a little bit of research]]. That begin said, US Marines don't wear berets. A Maroon beret, used by one of the models, would indicate they are from the Army's airbone troops.
** Many times, the HECU troopers refer to themselves as "soldiers", which is a huge BerserkButton for US Marines, who [[InsistentTerminology insist to be called "marines" rather than a "soldier"]]. Even the drill sergeants, who are supposed to literally drill the corp's internal culture into the new recruits, refer to them as "soldiers".
* AssholeVictim: All of the ones that feel no remorse or hesitation in killing the staff. When they themselves end up being betrayed and marked for assassination, it's very satisfying.
* BadassArmy: Consists of highly trained marines with a full repertoire of US Military hardware, including M1 Abrams tanks, M2 Bradley [=IFVs=], Apache attack helicopters, and even F-16 fighters. Unfortunately for them, they're a mere battalion-sized unit facing an entire alien invasion. Not to mention [[OneManArmy Gordon]] [[PlayerCharacter Freeman]].
* BandOfBrothers: Subverted and played straight. Many soldiers throughout ''Opposing Force'' are shown to care for their squadmates, but the same can not be said for many other members of the unit, particularly the commanders, who abandon several dozen soldiers in their attempt to escape from Black Mesa in blatant violation of the "Never Leave a Man Behind" policy. In fact, two of the soldiers refuse to turn Gordon over to their bosses because they don't want to see him alive after he'd killed so many of their compatriots.
* TheBigGuy: Yet another class introduced in ''Opposing Force'' is a tall, muscular soldier toting an M249.
* BookDumb: They tend to come off as a bunch of macho idiots, yelling "We will kick your ass!" and leaving behind messages such as "YORE DEAD FREEMAN." Even so, they are among the few enemies in ''Half-Life'' to employ squad tactics, [[ArtificialBrilliance among other surprising strategies]].
* CavalryBetrayal: You rather quickly find out that they are not at Black Mesa to help the employees and especially not Gordon.
** They later end up [[LaserGuidedKarma on the receiving end of one]] when the Black Ops show up and start killing them along with the facility staff.
* ColdSniper: A handful of them wield sniper rifles in the original ''Half-Life''. [[PlayerCharacter Shephard]] himself can wield one of these rifles in ''Opposing Force'', and even receives specialized training for use of one beforehand.
* DrillSergeantNasty: The ''Opposing Force'' training level has one guide you through, quoting ''Film/FullMetalJacket'' the whole way.
-->"Where are you from, soldier? ... "Texas"?! Holy cow! You know what comes from Texas, don't you?"
* EarlyInstallmentCharacterDesignDifference: The original models in the first game had more of a comic book stylization, with fictionalized combat gear and urban camoflage based on the Swedish M90 pattern, along with vests resembling studded SWAT vests rather than military body armor. ''Opposing Force'' and subsequent ports of the first game based their appearences on infantry seen in the 'Operation Urban Warrior' US military trials of the late 1990's, with gear better resembling real-world equipment. Their camoflage was updated to an urban camoflage version of the M81 Woodland pattern, along with replacing the original's full-fingered gloves to their iconic FingerlessGloves and introducing the Powered Combat Vest.
* TheEngineer: He gets introduced in ''Opposing Force''. While engineers are meant to fix vehicles, the engineer in ''Opposing Force'' is more useful for just opening locked doors with his blow torch and fighting with his [[HandCannon Desert Eagle]].
* FacelessGoons: The shotgun wielding ones wear balaclavas, while some wear [[GasMaskMooks Gas Masks]].
** Averted in ''Opposing Force'' for the most part, where they actually have their faces shown.
* FieryCoverup: Their entire mission, at least until they were ordered to pull out.
* GasMaskMooks: Some of the most common models wear gas masks. [[JustifiedTrope Justified]] as they are part of the ''Hazardous Environment'' Combat Unit, and the disaster in Black Mesa can have exposed various radioactive, chemical and biological hazards.
* HateSink: The more evil soldiers, specifically the ones who not only show no remorse or hesitation in killing the Black Mesa staff, but state that they are happy that they get to kill someone and complain about how easy it is to kill the Black Mesa staff due to them not putting up a fight. The ones who hate Gordon for killing their buddies are also this, since they [[MoralMyopia don't care that it was in self defense after they had betrayed and started killing many members of the Black Mesa staff]]. The commanders who leave their troops to fend for themselves are also this. While many of the others can be seen as [[PunchClockVillain punch clock villains]], these other assholes deserve to be killed and serve as good human antagonists that serve the role of someone the audience can hate.
* {{Jerkass}}: The soldiers who are happy they get to kill people, find it annoying that the staff don't put up much of a fight, feel no remorse for their actions, and hate Gordon for killing their men despite it being completely justified.
* LaserGuidedKarma: They think nothing of being what is essentially a government cleanup force, or slaughtering innocent scientists and security guards when ordered to. However, when they fail to contain the alien invasion, the HECU themselves are marked for cleanup by [[AlwaysABiggerFish the Black Ops]].
* TheMedic: ''Another'' class introduced in ''Opposing Force''. While he isn't very effective with his Glock 17 handgun, he ''is'' the only thing in the game that can heal your teammates.
* MookCommander: Beret-wearing Marine squad leaders provide coordination for their squad, and also make good usage of their [=MP5=]'s undermounted grenade launcher.
* MoralMyopia: Two soldiers that capture Gordon seemed rather outraged at him for killing so many soldiers, even though 100% of those guys were trying to kill Gordon.
* OhCrap: Occasionally they will yell [[https://www.youtube.com/watch?v=YfoTP0Yyidk&t=391s "Oh SHIT!"]] when a grenade is thrown at them.
* {{Retcon}}: Originally, they were only called "soldiers" or "the military" and lacked the Powered Combat Vests. They received their current name and equipment in ''Opposing Force''. In the original ''Half-Life'', their helicopters even had a US Army logo on them.
** Given this, and some other facts (HECU grunts are recognized as marines, land vehicles have Army markings, the F-16 is a plane used by the USAF) some fans have theorized that HECU is a multi-branch effort, like SOCOM in real life.
* MoreDakka: Many of their weapons, such as the M249 and Flash missile launcher. Hell, even their standard issue sub machine gun has a 50 round magazine.
* RadioVoice: They spoke this way, and it sounded extremely robotic. May have something to do with most of their EnemyChatter being MadLibsDialogue. Averted in ''Opposing Force'' to make them more relatable as Shepard's comrades.
* RedShirtArmy: Zig zagged. They're actually capable of soaking up more damage than the aliens thanks to their [[PoweredArmor PCVs]] and are more than capable of taking them in a fight. On the other hand, Gordon slaughters them by the score and their AI leaves a lot to be desired in ''Opposing Force'', where they can often be easily killed by Black Ops troops.
* SemperFi: The unit is first referred in the original game only as "the military". In ''Opposing Force'' they are given the name of ''Hazardous Environment Combat Unit'' and stated to be part of the US Marine Corps. Although as noted in ArtisticLicenseMilitary and {{Retcon}}, a lot of individual details don't make sense for a Marine unit. The most likely reason is that the HECU became a Marines unit to emphasize their BadassArmy status.
* ShotgunsAreJustBetter: The ones who wear balaclavas certainly think so.
* ShoutOut: To the rogue Marine unit in ''Film/TheRock'', given that both share overall villainous roles as Marine units clad in urban camoflage and black combat vests.
* SociopathicSoldier: A few of them seem to take joy in killing innocent scientists.
-->"I've killed twelve dumbass scientists, and not one of them fought back! This sucks!
** PunchClockVillain: Most of them, however, just do what their commanders tell them to, as evidenced by various lines throughout ''Half-Life'' and ''Opposing Force''.
--->"[[NotWhatISignedOnFor I didn't sign on for this shit!]] Monsters sure, but civilians? Who ordered this operation anyway?"
--->"Government cover-ups were ''[[NotWhatISignedOnFor not]]'' [[NotWhatISignedOnFor in my job description]]!"
* SuicideMission: After the Marines evacuate, they leave several soldiers behind. These soldiers, despite essentially being doomed men, still fight on to kill the more powerful aliens and therefore prevent them from ransacking Earth. Especially noticeable in ''Opposing Force'', when the corpses of dead marines can be found in the area where you fight the pit worm. Also in the final boss battle, when the security guard tells Shephard that some other marines went down to fight the Gene Worm and never came back.
* TakingYouWithMe: When critically injured, Marines will often drop a live grenade at their feet, presumably in an attempt to do this. Often, they just end up blowing themselves up instead of letting you finish them off, though it doesn't seem to be a case of BetterToDieThanBeKilled because they do make an attempt to run away from the grenade if you don't kill them immediately.
* WhiteAndGreyMorality: Their main job is to prevent an alien invasion, which means protecting Earth. Plus, it is hinted at in their conversations that they mistakenly believe Gordon (and by extension all the scientists at Black Mesa) intentionally caused the Resonance Cascade.
--> "So, who is this guy, Freeman?"\\
"They say he was at Ground Zero."\\
"Science Team? You think he was responsible, sabotage, maybe?"\\
"Yeah, maybe. But one thing for sure is he's been killing my buddies."\\
"Oh yeah, he'll pay. He will ''definitely'' pay!"
* WithCatlikeTread: [[NoIndoorVoice "SQUAD, QUIET DOWN!"]]
* YouAllLookFamiliar: They had exactly four models in the original game, which just changed the head: the caucasian officer who wore a beret, the normal mook who wore a gas mask, the shotgun using soldier who wore a balaclava and goggles, and the grenade launcher using African-American soldier who wore no hat or mask, and smoked a cigarette. The latter was changed to simply being an African-American version of the officer with a mustache in the HD pack.
* YouHaveFailedMe: After they fail to defeat the aliens and start pulling out, the Black Ops come in to deal with the situation themselves by blowing the facility up to kill the aliens and ensure the incident is covered up. They not only have no interest in rescuing any of the HECU troopers still present at the facility, but in fact start killing any of them they come across, as they have decided that the HECU stragglers could be just as much a liability as the Black Mesa staff if they were to survive and don't want to risk them getting word of the incident to the public. Also, the Black Ops just don't like the HECU and look down on them.
[[/folder]]

[[folder:The Black Ops]]
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/250px-black_ops_all_7309.jpg]]
A very shadowy unit sent to Black Mesa after the HECU failed their tasks, the Black Ops are there to remove ''everything'' in the facility, including the dozens of HECU stragglers left behind. Their purpose is only explained in ''Opposing Force''.
----
* ArmiesAreEvil: Played straight. Unlike the HECU, who are shown to at least be a BandOfBrothers and show bravery and camaraderie against all odds, these soldiers are straight-up evil, massacring ''anyone'' who isn't part of their unit remorselessly.
* AwesomeMcCoolName: In the game files, the name of the first two Black Ops you see in ''Opposing Force'' (the two having a dismissive conversation about the HECU) are Max Iron and Jake Rockwell.
* BadBoss: HECU soldiers find this out in a [[YouHaveFailedMe bad way]].
* BadassArmy: They use the same equipment as the HECU, but are also far more competent in combat, managing to hold out far longer against the Xen and later Race X hordes, not to mention having more health than the HECU soldiers. Also, the fact that they never make noise is pretty impressive when they're being shot constantly.
* BlackHelicopter: They use black [=AH-64=] Apache attack helicopters, in contrast to the green ones used by the HECU.
* CavalryBetrayal: Shephard, and by extension, the remaining HECU soldiers in Black Mesa, realize that they're not there to help them pull out, but are ordered to silence them along with any surviving Black Mesa personnel as well as the aliens.
* ColdBloodedTorture: In ''Opposing Force'', after defeating a bunch of Black Ops in a garage, Shephard finds an engineer who is bleeding and mortally wounded. He has to bring the nearby medic to him in order to save his life so he can open a door for you. It is clear the Black Ops tortured him for information.
* ColdSniper: Some of them (or rather [[UniqueEnemy one of them]]) have sniper rifles.
* DarkIsEvil: They wear all-black combat suits, and are absolutely ruthless in their containment of the Black Mesa disaster.
* DeusExNukina: [[spoiler:The way they eventually take care of Black Mesa.]]
* DoomTroops: the HECU may be a [[PunchClockVillain diverse]] [[JustFollowingOrders lot]], but these guys are a straight Legion of Terror.
* EliteMooks: In addition to being completely silent, the male black ops use powerful spin kicks at close range, run much faster than the marines, and have a little more health. They also all seem capable of using their [=MP5=]'s undermounted grenade launcher, instead of only squad leaders and demolitionists doing so like the HECU. The female black ops on the other hand prefer to flip and jump around wildly while pelting the player with pistol fire and kung-fu kicks.
* EvilHero: Technically, their main goal is to stop an alien invasion and keep Earth safe. However, they are still sociopathic brutes who have no problem ordering the execution of all the Black Mesa staff just to cover-up the incident, and they are absolutely ruthless, merciless, and amoral in their methods. They have no problems torturing others for information, and they are ready to execute the Hazardous Enviornment Combat Unit troopers still present as punishment for [[YouHaveFailedMe failing to cover-up the incident themselves]] and because they now consider them a liability. Unlike the HECU, they display no real redeeming traits. The best that can be said about them is that they are still ultimately ALighterShadeOfBlack compared to the Race X and Xen aliens.
* FacelessGoons: They all wear balaclavas, and the female black ops, as well as some male black ops, also wear night vision goggles. Referenced in ''Opposing Force'' when one Marine refers to them as "masked freaks".
* FieryCoverup: Same mission as the HECU, except this time, their coverup also includes ''the HECU themselves''.
* FragileSpeedster: The female variant can move very fast, and do a lot of damage with their pistols to both Freeman and Shephard. However, they're easily taken down in one-two Magnum pistol hits.
* {{Gainaxing}}: The Female Black Ops had a very exaggerated breast bounce when they walked, never mind they wear absolutely [[SpyCatsuit skin-tight overalls]].
* GiantSpaceFleaFromNowhere: The Female Black Ops' appearances in ''Half-Life'' aren't explained at all. It was often assumed that they worked on behalf of the HECU soldiers. ''Opposing Force'' explains their presence in greater detail.
* HateSink: While some of the [=H.E.C.U.=] troopers could be seen as {{Punch Clock Villain}}s, the only redeeming quality about the Black Ops is that they look cool.
* HighlyVisibleNinja: Their pitch-black scheme does stand-out in well-lit areas. Unless you play on Hard (at least in the first game), in which case [[spoiler:the female ones have {{Invisibility Cloak}}s]].
* {{Jerkass}}: All of them. They order the deaths of all of the Black Mesa staff without any hesitation or remorse, and move on to kill their pawns when they are no longer needed. Unlike the H.E.C.U, none of them have any redeeming qualities outside appearance.
* KarmaHoudini: Though Shephard manages to kill dozens of them, in the end they still killed dozens of Shephard's colleagues and other innocent witnesses of the Black Mesa incident, successfully blew up Black Mesa and everyone left there, and they got away with the full support of the government.
* KarmaHoudiniWarranty: If they took part in the Seven Hour War, it's safe to assume the Combine soundly defeated them, and even if they didn't, they were most likely promptly disbanded following Earth's surrender.
* LeanAndMean: Even the male Black Ops are noticeably leaner than the bulky HECU Marines. They also tend to stand straight instead of hunching over in combat like the Marines do.
* LeaveNoWitnesses: And that ''includes'' the [=H.E.C.U.=] marines who are already doing just that.
* LightningBruiser: Male Black Ops move much faster than their HECU counterparts, and are tougher to take down.
* MakeWayForTheNewVillains: They naturally assume this position, being the second cleanup crew sent into Black Mesa to wipe out everything, including the first cleanup crew.
* {{Ninja}}: They are ninjas in all but name, complete with silent, fast movement and using karate kicks and punches at close range. Even their uniforms have a "kabuki stagehand" vibe to them.
* RadioVoice: Averted, even though you only hear them speak once (they're completely silent the rest of the time).
* SilentAntagonist: Most of them never speak a single line in and out of combat, and are antagonistic towards both Black Mesa personnel and the HECU.
* ShotgunsAreJustBetter: Averted, they never use them. Almost every basic Black Ops soldier uses an automatic weapon instead.
* SociopathicSoldier: Unlike the HECU, played completely straight.
* SpyCatsuit: The female soldiers are well-known for wearing these. Downplayed with the male soldiers, as their outfits are a bit more modest, but still relatively form-fitting.
* VanInBlack: Well, M35 ''truck'' in black.
[[/folder]]

[[folder:Race X]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/race_x.jpg]]
A mysterious alien race from another dimension they only appear in ''Opposing Force'', where their invasion is repelled by Adrian Shephard, and finally ended when the US government nukes Black Mesa. Their main soldiers are the Shock Troopers but they also have other creatures at their disposal such as the Pit Drone, Shock Roach, Voltigore, Pit Worm, and Gene Worm.
----
* AliensAreBastards: Between them and the Xen aliens, they're the worse of the two. The Xen aliens are attacking everyone in the facility out of instinct and use Earth as a hiding place from the Combine, and despite their antagonistic status, they can be pitied to some degree given the suffering they endured from the Combine. Race X on the other hand want to wipe out all life on Earth and steal the resources for themselves.
* ArcVillain: They serve as the main antagonists of ''Opposing Force'', continuing to exploit the Resonance Cascade even as the Nihilanth is killed.
* BigBadEnsemble: Form one not only with the HECU and Xen aliens but also with the Black Ops later on.
* ChuckCunninghamSyndrome: Haven't been seen since ''Opposing Force'', and Marc Laidlaw has said that they were purely a Gearbox creation and don't figure into his thinking about the universe. He also wanted to leave them alone to allow Gearbox to freely use and develop them in any potential future ''Half-Life'' titles they might make.
* EasilyThwartedAlienInvasion: Their invasion is pretty much stuffed by one Marine with small arms (with occasional back-up from small groups of comrades), and unlike the Xenians their defeat doesn't cause damage to Earth by proxy.
* EldritchAbomination: The Gene Worm is a gigantic monstrosity which has the power to convert any natural resource and by extension an entire planet in order to suit Race X's needs. It also houses an exit portal for reinforcements in its abdomen.
** The manual for Opposing Force implies that it's several miles long and that the portion you fight in-game is just its head.
* EliteMooks: Their units tend to be tougher than their Xen equivalents. Pit Drones are much faster and more aggressive than Vortigaunts, have a much higher rate of fire, have slightly more health, and tend to attack in larger groups. Shock Troopers have about 50% more health compared to Alien Grunts, can throw spore grenades, and move quickly and use squad tactics.
* EyeScream: Shooting the eyes of the Gene Worm with the conveniently placed laser turrets blinds it...
** AttackItsWeakPoint: ...if blinded in both eyes it opens its midsection revealing a portal, making it vulnerable to attack.
* FragileSpeedster: Pit Drones. They're incredibly fast, agile, and can kill Shephard and other human soldiers in a few hits. However, compared to the larger Race X troops, they die rather quickly from just a few shotgun blasts or submachine gun rounds.
* GiantSpaceFleaFromNowhere: They're essentially an ''entire race'' of this since they're not connected to the Resonance Cascade nor the Xen aliens, and only appear in ''Opposing Force'' to take advantage of the whole incident in an attempt to raid Earth. They're not even given a backstory and any relevance to the main plot beyond that.
* HairTriggerTemper: The Shock Roaches will attack anything close to them, including their own handlers (like Adrian). Heck, the idle animation shows Adrian teasing the Roach and it wanting to attack his fingers.
* InterimVillain: They serve as antagonists just as the Xen invasion begins to peter out thanks to Gordon Freeman's actions, and before the Combine make their invasion of Earth.
* LightningBruiser: Shock Troopers move fast, take a lot of damage from both bullets and explosives, and deal a lot of damage in return. In fact, they have even more health than the Male Assassins, already known for being {{Lightning Bruiser}}s themselves.
* MadeOfExplodium: The Shock Roaches also eventually explode after being released.
* MadeOfIron: Shock Troopers take about twenty [=MP5=] shots to kill, or just three Desert Eagle shots. That's twice as much as the average human soldier.
* MakeWayForTheNewVillains: They take over from the Xenians as the dominant alien threat midway through ''Opposing Force'', in the same way that the Black Ops become the dominant human threat.
* MightyGlacier: Voltigores are this, being able to soak up a ton of bullet and even explosive damage before dying.
* PlanetLooters: Their goal regardless of origin and affiliation is all very much the same: conquer a planet while also plundering all of its resources, and then terraform it so it can be of better use as a more suitable colony.
* PlasmaCannon: A variant; the Shock Troopers are armed with a powerful plasma rifle that hits like a truck (twice as much damage as the base assault rifle), has infinite ammo, and can gib people it kills, with its main drawback being that its projectiles are relatively slow (and unguided, unlike the Alien Grunts' weapons). The plasma rifle just happens to be a living insect.
* ShockAndAwe: The aptly named Shock Troopers which carry a weapon called a Shock Roach, insect-like creatures that shoot deadly electricity. Also, Voltigores, large creatures which shoot powerful bolts of purple electricity.
* StarfishAliens: Even more so than Xen's occupants which is saying a lot. For example, Shock Troopers, in their infantile stage, are green amphibious fish-like organisms; by the time they reach maturity, they gain a humanoid stature, two pairs of arms, and have more in common with insects than fish.
* TheSpook: Infamously known for this. The only things we do know about them is that they're interested in conquering and colonizing other planets, and that they have already mastered teleportation technology. Even in-universe, the higher-ups at Black Mesa didn't fully know about their existence despite the countless research expeditions made on Xen.
-->'''Security Guard:''' What is that thing, doc?
-->'''Scientist:''' I don't know, I've never seen that species before!
* UglyCute: InUniverse, Shephard seems to think so of the Spore Launcher, since he can't help but pet the cute thing (which is actually a larval infant of the Shock Troopers, according to WordOfGod.)
* ZergRush: The preferred tactic of the Pit Drone, taking advantage of their speed and numbers to overwhelm HECU and Black Ops positions.
[[/folder]]

[[folder:The "Employers"]]
An unseen group of entities whom the G-Man serves, and who authorize him to interfere in the games' events on their behalf.
----
* AmbiguouslyEvil: What they want is unknown, but while they oppose the Combine, they do not want them removed from Earth. Through the G-Man, they caused the Resonance Cascade that brought the Xen aliens and Combine to Earth, but the Combine was implicitly aware of Earth beforehand. The "Employers" also help the human resistance by preserving Gordon Freeman, but destroying the Citadel’s reactor was considered good enough for their purposes. Whether they're helping humanity or using the conflict on Earth as part of a larger plan is unclear. Whatever the case, they initiated the games' conflicts and remained in the background as humanity was conquered.
* AmbiguousSituation: Everything known about them, which is very little, is based on what the G-Man says, which is unreliable information at best. Perhaps he's their MouthOfSauron and [[TheDragon Dragon]], or maybe they don't even exist and he's lying to the player characters.
* ForWantOfANail: They let the G-Man "nudge" things with this kind of effect.
* MysteriousBacker: Of the G-Man and multiple player characters. Freeman only survived Black Mesa because they encouraged the G-Man to save him for future use.
* OnlyKnownByTheirNickname: The label "Employers" is one used by the G-Man, no other name for them has been given.
* PragmaticVillainy:
** Although the Employers can and will "hire" strong individuals to serve their causes, that doesn't necessarily mean they're going to hire anyone. While Gordon Freeman and Alyx Vance were chosen by the Employers personally to complete the assignments, Barney Calhoun was not, and thus the Employers had "no further comment" on him after he escapes their range in ''Blue Shift''.
** Downplayed with Adrian Shepard however. While the Employers initially wanted to have him killed to prevent any witnesses from revealing what happened at Black Mesa, the G-Man was able to convince them to detain him instead, due to his ability to "survive against all odds".
* ScrewDestiny: According to the G-Man, they believe in this idea, refusing to accept the inflexibility of fate.
* SpockSpeak: If the texts that appear during game introductions and credits (ex. Barney, Shephard and Gordon's age, occupation and education, etc.) is their own way of keeping tabs on people of interest, assuming it isn't the G-Man's own observations being relayed to them. These also appear if the player fails in a specific way (''Assignment Terminated: Failure to preserve mission critical resources.'' when Gordon's buggy is destroyed) or before the credits roll for a final word on a character's status.
--> '''Subject:''' Freeman
--> '''Status:''' Hired. [[SequelHook Awaiting assignment.]]

--> '''Subject:''' Shephard
--> '''Status:''' Detained. [[PutOnABus Further evaluation pending.]]

--> '''Subject:''' Calhoun
--> '''Status:''' [[EarnYourHappyEnding Out of range.]] No further comment.

--> '''Subject:''' [[spoiler:Alyx Vance]]
--> '''Status:''' [[spoiler:[[WhamLine Hired. Awaiting assignment.]] ]]
[[/folder]]

* HateSink: While some of the [=H.E.C.U.=] troopers could be seen as {{Punch Clock Villain}}s, there is ''nothing'' to like about these people.

* {{Jerkass}}: All of them. They order the deaths of all of the Black Mesa staff without any hesitation or remorse, and move on to kill their pawns when they are no longer needed. Unlike the H.E.C.U, none of them have any redeeming qualities whatsoever.

* ArtificialBrilliance: They were praised as being the first tactically intellegent enemies in video games. They regularly throw grenades, take cover, and work as a squad to attack from multiple angles.

* BandOfBrothers: Subverted and played straight. Many soldiers throughout ''Opposing Force'' are shown to care for their squad mates, but the same can not be said for many other members of the unit, particularly the commanders, who abandon several dozen soldiers in their attempt to escape from Black Mesa in blatant violation of the "Never Leave a Man Behind" policy. In fact, two of the soldiers refuse to turn Gordon over to their bosses because they don't want to see him alive after he'd killed so many of their compatriots.

* BookDumb: They tend to come off as a bunch of macho idiots, yelling "We will kick your ass!" and leaving behind messages such as "YORE DEAD FREEMAN."

* KillEmAll: She gives the order to 'de-service' all prisoners in Freeman's area when he breaches Nova Prospekt to prevent them from meeting. You can find possible evidence of this when you reach a prison cell where a dead Vortigaunt was strapped to a chair and apparently executed.

* SmugSnake: Things escalate beyond his control rather quickly. He also gloats about being able to effectively demand ''anything he wants'' from the Combine in exchange for handing over Eli, but while it is true that Eli's knowledge of how to achieve local teleportation would be very valuable for the Combine, "anything I want" is probably a tad presumptuous.

* IDidWhatIHadToDo: Breen rationalizes his actions on the grounds that The Combine were going to simply exterminate humanity in its entirety to take earth's resources and what technology we had invented. Dr. Breen convinced them to spare humanity on the condition we proved ourselves worthy of being assimilated. At least on paper his actions make sense but in the process he secure a comfortable position of power for himself and proceeded to lord it over the remains of humanity, effectively ignoring the fact that we were still condemned to extinction by the suppression field. He may have saved humanity but for his own sake rather then humanities as a whole.

* NiceJobFixingItVillain: He takes the Gravity Gun with him to escape, frees the heroes by accidentally triggering it, and leaves it on the floor before Alyx and Gordon catches up to him, allowing Gordon to take it back and defeat Breen.

* SmugSnake: Things escalate beyond his control rather quickly.

* AmbiguouslyJewish: Has a Hebrew given name and a German surname, and named his pet headcrab after a Jewish actress.

* CurbStompBattle: Him versus any Combine forces short of a Strider. His favored method is to pick up ground vehicles and throw them at the enemy.

->'''Voiced by:''' [[HeroicMime Nobody]]. (No, neither [[Machinima/FreemansMind Ross Scott]] nor [[Machinima/HalfLifeButTheAIisSelfAware WayneRadioTV]] count.)