Big things are happening on TV Tropes! New admins, new designs, fewer ads, mobile versions, beta testing opportunities, thematic discovery engine, fun trope tools and toys, and much more - Learn how to help here and discuss here.
This page is for the Half-Life series as a whole. If you're looking for the first video game in the series with the same name, please click here.
You can't even walk down the street of your own planet anymore! I remember the good old days when I didn't have to bring a gun to work, my coworkers weren't space bugs, I had a salary, I wasn't wanted by the government... [spots an alien] Then you happened!
Half-Life is a series of First Person Shooters created by Washington-based developer team Valve. The series follow the life of physicist Gordon Freeman, a bearded, bespectacled Heroic Mime who works in the Anomalous Materials laboratory at the vast Black Mesa Research Facility, a top-secret complex in the middle of the New Mexico desert.
Portal is a side story to the series, whose plot has evolved almost completely separately given that it takes place entirely inside the Aperture Science complex, established in-game as a rival to the Black Mesa Research Facility. Because of its enormous popularity, it seems to have overtaken the Half-Life series as the focus of Valve's attention for now, projects like Team Fortress 2 and Left 4 Dead (obviously not set in the main Half-Life universe) notwithstanding.Finally, there is Black Mesa, a free Fan Remake of the original Half-Life using the Source engine used for Valve's newer games. It's very well done, and Valve itself has expressed admiration for it.The series now has a Recap page covering all games as well as both Portal games. It is currently a black hole of red links and is in dire need of Wiki Magic.There is a Steam group made by (and populated with) Tropers. Check it out here and join up!This page applies for the series as a whole. Please add any examples from an individual game to their dedicated pages.
The Half-Life series contains examples of:
open/close all folders
Abandoned Mine: Towards the end of Ravenholm and much of the early setting in Episode 2.
Abandoned Hospital: One of the settings in Episode One, which appears to have been taken over by the Combine. The impending city-sized explosion left it in the process of being abandoned again
All Deserts Have Cacti: The original Half-Life has a few saguaro cacti in the outdoor areas... despite being located in New Mexico. (While New Mexico has cacti, it doesn't have saguaros.)
All There in the Manual: Averted, as part of the series' unique storytelling strategy. Despite you having been missing and in stasis for several years between parts 1 and 2, at no point does anyone explain to you what the hell happened during that time, nor does Gordon ever ask to be filled in. Unless you look at every newspaper clipping along the way, you can complete the entire game without any knowledge of the "Seven Hour War" or of what the Combine really is. Also, the only character that gives any real exposition is very easy to miss if you don't know where to look for him. If you have a lot of free time and possess an insane measure of dedication, you can construct a reasonably coherent picture - read this timeline to get the most probable theory.
Alternate Character Interpretation - In-universe. While it's implied quite a few Marines are having second thoughts of shooting civilians to cover-up the Black Mesa incident, everyone in the HECU wants a piece of Gordon Freeman - scuttlebutt had him killing a few Marines in cold blood, not to mention they believe him to be the one responsible for the whole mess (and not just the guy who pushed the crystal in).
Ambiguous Robots: Pretty much everything you fight in the Half-Life 2 series (less headcrabs, zombies and antlions) is ambiguously cyborg in nature. The flying synths and the Striders are probably the most ambiguously robotic.
The shadowy Hazardous Environment Combat Unit who serves under the US military and who, thanks to their orders to kill the personnel of Black Mesa, is one of the main threats in Half-Life.
HECU gets their own Army in the even more shadowy Black Ops unit, who apparently goes even higher in command. Like the HECU, they're also there to stop the alien infestation after the HECU fails, with predictable results.
Artificial Brilliance: Half-Life was widely praised for the A.I. of its human Marine enemies, who were the first FPS enemies to work in squads and use complex tactical behaviors and movement patterns instead of simply charging in a straight line at the player...
Artificial Stupidity: Especially true of the HECU marines, who, despite showing off some pretty sophisticated AI behavior for the time, will break instantly as soon as there's more than one player, since it was heavily dependent on rigid scripting. Furthermore, while they are programmed to place grenades on the ground to cover their retreats, you can shoot them in the act, breaking that bit of programming and causing them to shoot back instead, instantly forgetting all about the armed grenade there is right beneath their own feet.
HECU marines will also lay down laser trip mines on occasion to block off routes for the player. However, sometimes they'll place one in the only exit out of an area they're in and will run right into their own trip mines to search for the player if they cannot attack the player from their current position.
Civil Protection officers will take cover behind explosive barrels, stand on the most rickety and fragile structures they can, and rappel in front of a moving vehicle only to get immediately run over. Most of this is scripted, but they're still not very smart otherwise.
The HECU also had a hilarious habit of mixing up their reactions to grenades. When a Marine shouts to his comrades he's throwing or putting down a grenade, they normally crouch and cover their head, while he runs away from the grenade. Sometimes they get confused, and the Marine will put down the grenade at his feet, then crouch beside it and cover his head, and of course be blown to bits. Easy kill.
Friendly NPCs in HL1 and Opposing Force both had a tendency to shoot you if you happened to be between them and an enemy.
Autodoc: Both first aid stations, which heal you, and similar looking HEV stations, which recharge your HEV suit.
Autosave: The games autosave in certain places or intervals. If you want to to back before an autosave, you can always load the previous save file.
Backdoor Pilot: Portal was developed by a small team with a limited budget who wrote the game into the Half-Life continuity so they could re-use those games' assets. Now that it's a standalone franchise.
Badass Bookworm: Gordon, duh. Dr. Breen himself is perplexed, and had this to say on the matter:
"How could one man have slipped through your forces' fingers time and time again? How is it possible? This is not some agent provocateur or highly trained assassin we are discussing. Gordon Freeman is a theoretical physicist who had hardly earned the distinction of his Ph.D. at the time of the Black Mesa Incident. I have good reason to believe that in the intervening years, he was in a state that precluded further development of covert skills. The man you have consistently failed to slow, let alone capture, is by all standards simply that — an ordinary man."
More or less justified in every case: The G-Man took away all your weapons at the end of Half-Life* He said most of them were government property, and having your HEV suit would make it harder to get through the train station. In Episode One, you had already been stripped of everything but the gravity gun and your HEV suit very late in Half-Life 2. In Episode Two, all of your weapons had been thrown from the train when it derailed, and only the gravity gun was close enough for Alyx to find.
A variation/inversion of this occurs with the games' chapter systems. You can start a brand new game at the beginning of any chapter you've already reached; the game equips you with every weapon available at that point and a reasonable amount of ammo, plus full health and some HEV Suit Power, regardless of whether you have ever made it that far without running out of something or running low on health.
Body Horror: Headcrab zombies, which tore open the chest of the victim, and in the first game, fused the crab to the victim's head. In the second, it tore out their eyeballs and left them screaming for death. In Opposing Force, a headcrab zombie will mutate into a bigger, nastier, pile of flesh with green lumps everywhere and horrendous claws.
Stalkers, which are the emaciated, amputated, barely-sentient corpses of prisoners with rudimentary cybernetic implants drilled into their bodies.
Gordon would find random burnt corpses, or the disfigured bodies of what used to be those who were taken in by Civil Protection.
If Gordon rejects the G-Man's offer at the end of Half-Life, he is teleported unarmed into a room full of alien grunts. The game doesn't even show what happens, simply fading to black and showing "Subject: Gordon Freeman. Status: Terminated. Postmortem: Refused offer of employment."
The first game began and ended in a tram. Also interesting is that this seems to slightly carry over to the next game, where the player starts off in a train and also ends the game on a train, albeit the G-Man's metaphysical one. Episode One also ends with Gordon on a train, and Episode Two starts with you on a crashed train.
Opposing Force keeps the tradition, though the tram in this case is a V-22 Osprey.
Boring but Practical: In the first game, the most useful weapon was probably the humble Glock 17, the first gun you found, due to its common ammo and its amazing accuracy. It's almost a game breaker because no enemy can touch you at the range you can hit them with the pistol. The second game had the submachine gun, which was really useful for dispatching Civil Protection officers and Antlions. It's fairly inaccurate and weak, but ammo is literally everywhere and it fires extremely fast. It becomes next to useless after you get your hands on the (also boring but practical) AR2 and SPAS-12, though.
Boss Arena Idiocy: The Nihilanth is invincible by drawing upon the power of (and expending) energy orbs floating around its head, which get replenished by easily destroyable crystals on the walls of its chamber. Once the crystals are gone, the orbs eventually run out and the Nihilanth is toast.
Broken Bridge: Dozens of them. Lampshaded in Episode 2 by the Vortigaunt, who declares, "Pity the generator that requires a Vortigaunt to activate it."
Brains and Brawn: "With my brains and your brawn, we'll make an excellent team!" Except Gordon usually provides both.
In the very first game, you can repeatedly mess with a microwave until someone's lunch explodes and you get a What the Hell, Player? from a nearby scientist. The brick doesn't come crashing down for 3 sequels and 10 real-life years until you meet Dr. Magnusson, the owner of that lunch, in Episode Two. He's still annoyed about it.
A similar example, though with not as many years between: If you try to talk to security guards (the basis of the character Barney Calhoun) before the resonance cascade, one of their random lines is, "Hey, catch me later, I'll buy you a beer." In Half-Life 2, Barney's first line upon revealing his identity to Gordon is, "About that beer I owed ya."
During their first meeting in the second game, Dr. Vance lampshades this, saying "The last time I saw you, I sent you to get help after the resonance cascade. I didn't think it would take you this long to get back to me!" referencing a conversation with a (then-generic) dark-skinned scientist right after the cascade.
The major Wham Line in Episode 2, which is even more obscure because the words are the name of a level in the first game, that only appears as a caption and never spoken by anyone.
Cavalry Betrayal: The scientists and guards Gordon comes across in the first few hours after the resonance cascade will enthusiastically tell you that the US military have called in via radio and told that a team is under way to Black Mesa to kill the aliens and rescue the personnel of the facility. While the first part of the message is true, the team's orders have been changed (or always were) to terminate the personnel because of their status as witnesses.
Charged Attack: The Gauss Gun from Half-Life, the wrench from Opposing Force, and the mounted Tau Cannon on the buggy in Half-Life 2. The pistol in HL2 could originally do this but it was removed in a later patch.
The Chessmaster: "I do apologize for what must seem to you an arbitrary imposition, Dr. Freeman. I trust it will all make sense to you in the course of... well... I'm really not at liberty to say. In the meantime... this is where I get off."
Noclip and Impulse 101 are at the top of about 95% of the console code lists. If you have ever used the console, you probably use Noclip and Impulse 101 the most. By extension, sv_cheats 1 is well known, since it is needed to enable those two.
Clothes Make the Superman: Gordon's ubiquitous HEV suit. It's the only reason he was able to survive the resonance cascade at ground zero and kill the Nihilanth: he's the only survivor wearing (and trained in using) an HEV suit.
Combat Medic: The second game has them as resistance fighting the Combine. They'll charge in and gun down enemies with an MP 5 before running to Gordon to patch him up.
Cosmic Horror Story: As the games progress, one can't help but get this vibe with the series. Especially with the presence of the Combine, a force that comes off as some never ending horror series of atrocity after atrocity. Then there's the appearnece of guys like the Headcrabs and Antlions....
Copy Protection: Steam, which one must have to activate even retail copies of any Valve game since Half-Life 2.
Corridor Cubbyhole Run: At the exit to the Ravenholm mines, there's a buzzsaw trap that zooms back and forth along a track, shredding all the zombies in your way. It will also shred you or run you over if you don't stay out of its way.
Corrupt Corporate Executive: Dr. Breen, head administrator of Black Mesa. The research conducted under his administration would not hold up to any kind of ethical standards. May or may not have set up the entire Black Mesa Incident in order to be appointed head administrator of the entire human race.
The G-Man also seems to fill this role. He is always wearing a snappy business suit, after all.
Crapsack World: The entire planet Earth. Even if you do save it from the Combine, mankind's probably going to spend the rest of its existence fighting off Antlions and all the other alien monstrosities that call it home now. Ironically, the Combine seemed to be doing a pretty good job staving off those monstrosities. Making them something of a collective Load-Bearing Boss.
Justified in that the suit has built in medical tech and movement assisting features. Even when the reactive armour is inactive, the suit can absorb damage that should otherwise cripple or even kill the wearer, while the suit's medical systems administer medicine (refilled from health containers or stations) to take care of whatever manages to leak through. This is evidenced in-game by the manner in which the suit responds to the damage Gordon takes, such as applying morphine to dull the pain of a bone-breaking jump.
Damage-Sponge Boss: Most bosses in the Half-Life series are either a Puzzle Boss or can be defeated very quickly with a powerful weapon. The Gonarch, however, has no real other strategy to it than "circle strafe while firing all weapons at testicle, avoid white acid, run after it, repeat". It also has invincibility frames.
The Advisors, the enigmatic, grub-like psychic Overlords of the Combine Regime on earth.
Enemy Chatter: The HECU often communicate with each other and taunt Gordon, impressive for the late nineties. In addition, so do the Combine troops, which also have a city-wide Dispatch for the Metrocops. The Black Ops were considerably more silent, and much harder to predict, as a result.
Several times in the first game you need to escort a scientist from a hiding place to a door. Barney must also escort a scientist safely to escape Black Mesa in his expansion pack. However, these escort missions aren't too much of a pain, as you can tell them to stay put while you clear out the area ahead, and they will. That, and most of the "escort missions" in the game are optional.
Averted in Half-Life 2. Barney and Alyx both carry automatic weapons and have rapidly regenerating health, while Grigori gets a double-barreled rifle that can instantly kill most enemies and is almost perfectly accurate.
In Episode One, you have to escort civilians to the trains to escape City 17. This gets annoying after the first two trips, and when they start firing rockets at you.
In Episode Two, in order to get the "Little Rocket Man" achievement, you must "escort" (or rather carry, since it's just an item) a garden gnome from the first level all the way to nearly the end of the game. It's easy enough to fling it around for the start of the game, but it takes a lot of work to jam that thing in the car and keep it in place while you're dodging fire from a Hunter Chopper.
Eternal Engine: The Residue Processing chapter in the original, and the final Citadel level in the sequel.
Everything Fades: All of the games, but taken to extremes in the original, where breaking open a large crate produces, along with a useful item like ammo or a spare HEV suit battery, a small pile of random computer equipment that begins to fade away almost instantly (possibly to make the useful item easier to spot).
Evil Versus Evil: In the first game, in some chapters (such as On A Rail and Questionable Ethics), you could see HECU Marines gunning down Vortigaunts and Alien Grunts. For the most part they do a pretty good job, though they turn on you once the aliens are dead. In the second game, you can often find Combine soldiers fighting zombies and antlions. Once again, they do a pretty good job, but noticeably less so once Freeman destroys the Citadel and cut off the soldiers from their leadership.
In Opposing Force, Black Ops would fight with Race X - and if you were quick enough, you can see Race X Shockttroopers engage Vortigaunts.
All Combine have their faces hidden behind gas masks of some sort.
In addition, the Black Ops forces of Half-Life 1 and Opposing Force wore form-fitting balaclavas.
Most of the HECU wear chemical/biological warfare gear, including gas masks.
Fake Ultimate Mook: The two tanks you encounter in Half-Life are dangerous and can instantly kill you if they are able to land a hit. However, they are immobile and if you can avoid the extremely slow-moving turret (which can't make a full 360 degree turn), you can destroy them at your leisure. The first tank doesn't even have a machine gun.
The two Bradleys are a bit more dangerous, since their turret can actually swivel all the way around, but the first one still counts for this trope, as it oddly doesn't use its main gun, only firing missiles at you. These can be dodged and even redirected back at it. The second one, which actually uses its main gun, is much more dangerous, but it is still immobile.
Fan Remake: The much anticipated Black Mesa mod, which is meant to recreate Half-Life in the Source engine, and is made with Valve's blessing. The development has been a long process, but as of September 14, 2012 it has finally been released.
Headcrab zombies are quintessentially this; there's a strong implication within the game that the host is still semi-aware and screaming under the control of the Puppeteer Parasite. This was confirmed when someone took the sound files and played them backward.
The Stalkers — they're what happens when the Combine capture you and don't turn you into one of their transhuman soldiers. Body Horror only begins to cover it.
First-Person Shooter: Duh. What made the first game stand out to begin with was its emphasis on the "first-person" part: the entire game is viewed through Gordon's eyes.
Floorboard Failure: Happens quite often. Also happens in ducts as well (once into a room full of laser tripwire explosives).
The Nihilianth has an attack that will teleport you into another room. If it fails to hit you, it will instead teleport in a few Vortigaunts or Alien Controllers to aid him.
In several of the battles with Antlion Guards, normal antlions back them up. In 2 of these battles, they continue to spawn: In episode one they keep coming until you block the holes in the ground, and in the episode 2 double guard battle they don't stop spawning until after the Guards are killed. In the latter circumstance, you have a powerful ally Vort who can easily dispatch the normal Antlions for you, allowing you to focus on the boss.
The Gene Worm will periodically spawn Shock Troopers. Fortunately, this reveals its weak spot under its belly. Apply rocket launcher 3-4 times.
The Final Battle with an army of Striders at the end of Episode II has you taking out 2 dozen striders, each of which is backed up by 1-3 Hunters. Though at this point, they're more like Mini-Boss creatures that all attack at once.
Foreshadowing: In the tram ride of Half Life 1, the announcer says "More lives than your own will depend on your physical fitness."
Game Mod: Lots. The original GoldSrc engine and its successor Source are popular for modding in part because the SDK, which comes free with every game, is capable of effectively producing full standalone games.
Guide Dang It: For players that are used to using guns to kill enemies rather than physics, many will feel this when encountering a Hunter for the first time. They can take a ridiculous amount of damage from bullets and explosions, but have a crippling weakness to physics objects. This is made worse by the fact that the only other enemy that is really weak to physics is the regular headcrab zombie, and only to sawblades.
Gun Twirling: The idle animation for the revolver in both games.
Hazmat Suit: "Welcome to the HEV Mark 4 protective system, for use in hazardous environment conditions."
Heel Race Turn: All that's known about the Vortigants in the first is that they're invading aliens. In the second game it's revealed that they were confused and enthralled, and are now grateful for the destruction of their puppet leader. By the third, they gather en mass to support Gordon specifically.
His Name Is...: In the original Half-Life, in the level immediately after when the Marines first appear, a nameless scientist proclaims that he must be protected and knows everything about what's going on before charging straight into Marine gunfire and being mowed down. Of course, if you manage to save him, he has nothing special to say. There's also a security guard who is midway through telling you something important before being gunned down by Assassins.
In Episode Two, Eli Vance, as it is written somewhere on this page, is about to divulge critical information on the true nature of the Combine and the G-Man, before a pair of advisors literally break into the place and suck his brains out.
Hold the Line: Several examples, usually with easily-knocked over turrets.
Iconic Logo: Lambda-in-a-circle. The lambda is the most commonly-used symbol for the decay constant of a radioactive element, so it's appropriate to the title, even though it isn't a perfect match (for reference, there isn't a commonly accepted symbol for half-life in physics). It also happens to look like an arm holding a crowbar...
Idle Animation: For each weapon and NPC - for example, Adrian pets his living rocket launcher, and Barneys pull up their pants every so often.
Half-Life 2 has the Gravity Gun, which turns virtually anything into a weapon: Chairs, crates, tables, barrels (exploding and non-exploding varieties), benches, radiators, armoires, TVs, tires, bicycles, cars, people...
Informed Ability: The most technical things super-scientist Gordon Freeman has ever done are pushing a sample on a cart and plugging a teleporter in. Half-Life 2 explicitly refers to this fact. Early in the game Gordon has to plug in a cable and throw a switch, and Barney mentions that his MIT education is really paying off.
It has been pointed out that the only bit of physics that Gordon ever seems to apply is F=ma. That is to say, he knows how to swing a crowbar really hard... that is until the advent of the Havoc physics engine, where Gordon now understands simple machines like levers and pulleys.
Insurmountable Waist-Height Fence: Particularly in Half-Life 2, where, to demonstrate the physics engine, you must stack things to climb said fences. In addition, the first game often had locked doors blocking your way - you had to destroy or find alternate routes which deviate into God-knows-where (such as abandoned areas of the facility or the other side of that dam).
Ivy League For Everyone: Justified in the first game being set in a top secret research facility. Lampshaded by an NPC in HL2: Episode 1 who can be overheard saying "Sometimes it seems like everyone is a Doctor but me."
Jump Jet Pack: The HEV Suit has a long jump module that's effectively a big rocket attached to Gordon's back for crossing gaps his normal jump had no hope of reaching. Not used very much in the game and abandoned in the sequel.
Kill It with Fire: In the first game, you have to kill some Tentacles by igniting the rocket engine above it. Shortly thereafter, a Gargantua tries to kill you with fire.
A quick and relatively easy way of dispatching enemies in Half-Life 2 and episodes, given proper equipment (namely, the Gravity Gun and exploding things like gas cans); Father Grigori makes extensive use of fire traps to thin the zombie horde in Ravenholm. Just... try not to listen too closely when you light up a zombie.
Lab Pet: In Half Life 2, Dr. Kleiner has Lamarr, a pet headcrab.
Late to the Tragedy: Half-Life was the first game to subvert this, as the first level is a leisurely stroll through the player's workplace, before all Hell breaks loose. (Ironically, with all of the NPCs telling Gordon, "You're late!") Played straight in Half-Life 2, though, as Gordon is abruptly dropped into City 17 more than a decade after Earth's subjugation by the Combine, and played with - but ultimately straight - in Opposing Force: Adrian is part of the first HECU responders, but his Osprey is taken out. He regains consciousness just as the military begins its pullout.
Let's Split Up, Gang: Gina and Colette need to do this now and then to solve some of their puzzles. Gordon gets this line constantly from the NPCs he's paired with throughout Half-Life 2, often as a result of a bridge conveniently breaking itself to split the party. Functionally, it's a gameplay tool to force the player to go it alone.
Living Legend: The Free Man, who starts a revolution just by showing up. The Combine are well aware of the threat he represents and unleash their everything when they find out about him.
Living Motion Detector: The blind tentacles in the first game, and the canceled hydra for the second, somewhat brought back via scripts.
The computer voice in Half-Life: Deathmatch. The HECU would speak like this when in-battle with you.
The sound files for the Black Mesa PA system are individual words, so all PA dialogue is this.
Made of Indestructium: As with most video games, almost all of the scenery is invulnerable to your weapons in the first game. Some odd exceptions include the metal grates (which can be broken with a single crowbar swing, less than it takes to break most wooden crates) and the concrete barriers which instantly shatter when you run the tram car through them.
Mascot Mook: It is not uncommon to see people at standard nerd gatherings running around in cute little Headcrab hats.
May-December Romance: The implied romantic tension between Gordon and Alyx. Any relationship between them would technically be this, as Gordon is at least twenty years older than Alyx - although he's spent most of his life so far in stasis, so they're physically around the same age.
Mind Screw: The G-Man, especially in Half-Life 2 and its episodes.
Mook Bouncer: The Nihilanth has an attack that does this. Thankfully, he only does it four times. Unfortunately, the places he teleports you to get progressively worse. On the fourth, he simply teleports you to the third room with an unkillable extremely tough boss monster.
More Dakka: Opposing Force's M249. Thank you and good night.
The Striders' autocannons might not look all that dakkalicious alone, but when you encounter more than one... Same goes for Gunships, whice are using a similar autocannon model.
Mouth Flaps: Characters in the first game, due to engine limitations.
Nerf: The Source version of the original Half-Life, even on hard mode, has a lot less enemies to deal with in the Xen levels (and some other rare cases outside Xen) due to there not being as many walkover game-play triggers that spawn in new enemies; especially Alien Controllers. The "Interloper" level in particular really toned down on the triggers.
Nice Job Breaking It, Hero: Hey, dude, remember that big baby that you slayed in the first game? Alright, you had to kill him because he kept the hole between Xen and the Earth open, but it turns that he was also the only thing keeping the Combine at bay, and his death gave them the opportunity they needed to invade Earth.
The Black Mesa incident.
At the end of Half-Life 2 in the citadel in one of his breencasts, which is replayed once in Episode 1: " Tell me, Dr. Freeman, if you can. You have destroyed so much. What is it, exactly, that you have created? Can you name even one thing? I thought not".
Two instances from when Gordon first wakes up after the resonance cascade. The first allows you to hit an elevator button...that sends an elevator with three people on it plummetting to the bottom of the shaft. A later incident has you stepping on a flimsy catwalk, causing it to collapse under the scientist on it. He even yells "GORDON!" in a What the Hell, Hero? tone before falling to his death.
Although the elevator will fall whether you hit the button or not.
In Half-Life 2, toward the end of the game, Gordon goes through a weapon confiscator. It vaporizes all his weapons except for the Gravity Gun, which the confiscator is unable to destroy. Instead, the confiscator malfunctions and ends up making it more powerful.
In Half-Life: Opposing Force, Shephard manages to deactivate the nuclear weapon that Black Ops had wired to destroy Black Mesa. Shephard is forced to watch G-Man reactivate it, and there's no way to deactivate it again.
Nobody Poops: Gordon certainly doesn't, nor does he eat or sleep. The stasis between games might have rejuvenated him, but unless his suit has a diaper Gordon has been holding it in for at least four days. Although since the game is not really 72 hours long, there are several times in the story that he could have taken time out for those things, but which the actual game skips over because it's a game.
In the first game, Gordon could drink. There were several vending machines, each one can dispense five cans of soda, and each soda adds one health.
One of the chapters in the original Half-Life forces Gordon to go through a waste processing factory. Yes, it's flesh-burning acid, but fortunately Gordon's wearing the partially acid-proof HEV suit. Similarly, Adrian Shephard in the expansion has to go through some sort of experimental blast furnace, which has no rails or catwalks to shield workers, and is only accessible via a hole on the wall.
Then there's the massive toxic spill you can see on the opening tram ride... In fact, the whole facility is a disaster waiting to happen: there are no emergency exits directly leading to the surface in case of fire or extradimensional incursions, ceilings and catwalks collapse without warning, and an alarmingly large amount of objects, namely computers, are Made of Explodium.
One of the worst is a giant fan near the silo area. The only way to turn it on is by climbing down a ladder onto a narrow catwalk beneath the blades and pressing a button. The catch is that the fan blades touch the area anyone climbing the ladder up would be, so in order to survive the task you have to press the button and then haul ass and hope the fan doesn't catch you on the way out. One episode of the "Freeman's Mind" machinima openly gripes about this.
There is also the ladder in the elevator shaft, which is assumed to be there to fix the elevator in case it's broken. However, the only way to access said ladder is if the elevator is working.
There's also the fact that literally everything is apparently structurally comprised, from solid concrete ceilings and walls to steel catwalks. Even most of the elevators don't work. Pretty much the only things in the entire Black Mesa facility that are able to withstand any sort of damage whatsoever are the exit doors, and they're all locked.
In an interesting subversion, in Half-Life 2: Lost Coast, the headcrab cannon has OSHA standard signs on it. Naturally, you have to do exactly what they tell you not to do.
There's an achievement in Half-Life 2 called 'No OSHA Compliance' for killing some Combine soldiers with a crane. It's the Trope Namer.
Non-Standard Game Over: In Opposing Force, leaping through a portal Gordon leapt through in the main game sends you plummeting into space (instead of where Gordon landed) and accuses you of attempting to create a Time Paradox.
Other "status report" deaths:
Any time you let die a scientist who is needed to open a locked door or perform an important scripted event.
Turning and shooting Drill Sergeant Nasty during Opposing Force's tutorial gets you court-martialed.
Any overly excited person playing "Blue Shift" can accidentally (or purposefully) shoot the guard in the armory window in the crotch which the auto-aim automatically locks onto, or purposefully attack anyone else once you've receive your gun. This will result in Barney being fired for "improper handling of a Firearm." however there is a slight delay with the display and the game actually ending which gives you time to empty 1 or 2 clips of ammo into anyone you like.
No Sense of Personal Space: Freeman's squad habitually crowd around him so closely that it can be impossible to move without bumping into one or take a shot without dinging one by accident. One imagines Gordon got to know who used which toothpaste, they're that close — as noted here.
Take enough damage from falling, and you WILL gib.
More true to the trope, grabbing a ladder within inches of the terminal surface prevents any damage.
Fall any distance into water, no matter how shallow, and you'll be fine. Assuming it's not filled with leeches.
Not Worth Killing: The apparent reason why Barney Calhoun, Gina, and Colette successfully managed to escape Black Mesa on their own two feet, while Freeman and Shephard both ended up captured and put on deep freeze by the G-Man.
Oh, Crap: Toss a grenade into the sniper's nest, and one of his possible responses is a vocoder-muffled but still discernible "...SHIT!"
Practically your objective throughout Episode One. You pretty much succeed, but not entirely.
Path of Greatest Resistance: In Freeman's Mind he often says that when he gets lost, the best bet seems to be to follow the trail of corpses and bloodstains, and that the more dangerous the situation, the more he seems to be on the right track.
Plot-Powered Stamina: Gordon never has to stop to eat, sleep, or take a piss (though one might forgive that as a function of the suit). While he did get a break in between the original game and Half-Life 2, in which the G-Man probably started him at optimal health, he's on the go from then on with only brief moments of unconsciousness at the start of each installment. It isn't as if time isn't passing either; the sun starts setting as Gordon arrives at Black Mesa East, Ravenholm takes place at night, and the sun is just rising as Gordon emerges from the mines. When he arrives at the Vortigaunt Camp at the end of "Sandtraps", the sun is setting again, and at the end of "Nova Prospekt", despite a week passing in relative terms, Gordon still hasn't had any rest. The finale appears to take place shortly before sunset, so even if all you count is the original Half-Life 2, Gordon is up and moving constantly for over forty-eight hours without a break.
Pointy-Haired Boss: Dr. Wallace Breen was the administrator of Black Mesa at the start of the first game. Given, oh, everything that's happened since, I think it's safe to assume he wasn't the most competent administrator ever. Of course, in the sequel, he gets worse.
Power Armour: The HEV suit. The military PCV only half-qualifies, since it's just an armor vest built with the HEV electro-reactive armor.
Specifically averted with Barney Calhoun in Blue shift. Your armour is probably about as strong as the power armour, and despite coming across some HEV suit chargers here and there, you can't use them and can only renew your armour by picking up "undamaged" armour from other, less fortunate guards.
Power Limiter: The collars and bracers the enslaved Vortigaunts wear in the first game diminish their powers and render them the mooks of the Xen invasion. In the second game, when they can use their full powers... well, see Crowning Moment of Awesome.
Note that the Combine employ similar shackles for the Vortigaunts they capture.
Barney Calhoun appears to have been put on a train at the end of Episode One, not to be seen since. He is missed.
Colette Green and Gina Cross haven't been seen since the end of Decay, along with Dr. Keller.
Not really a major character, Otis Laurey from the Gearbox expansions Opposing Force and Blue Shift became an Ascended Extra in Decay (in the manual, at least), but hasn't been mentioned at all in the main Half-LifeCanon since.
Punch Clock Villain: The HECU Marines are just as confused as to why they're killing the Black Mesa workers as the workers themselves. Well, some of them are,at least.
Radiation Schmadiation: Only direct contact with radioactive waste causes any issues. Fair enough for Gordon, who has the HEV suit (designed for that sort of things) not valid for the few times NPCs also get near it unless it's stabilized.
Reckless Gun Usage: The player can twirl a loaded revolver at vital characters (it's part of an idle animation, and all conversations are in-game so you'll see it a lot) which almost guarantees a friendly fire incident or six. The sequel makes Gordon lower his weapon automatically when pointing the crosshairs at a friendly NPC so it no longer applies, though the player can still fire it (harmlessly) without aiming anyway.
Redemption Promotion: In the first game, when they're your enemies, the Vortigaunts are fairly low-level, easily disposed Mooks. In the second game, when they're your allies, they're incredibly powerful fighters whose beam attacks can kill an enemy in one hit and send them flying a few dozen feet. They're even powerful enough to counter-act the power of the then-seemingly unstoppable G-Man. He is not amused by this.
Possibly justified. See those shiny green things they wear in the first game? Those are slave collars similar to the ones the Combine put on them. They can't use their full power until the collars are removed.
Reference Overdosed: The series is notorious for having numerous hidden chemistry/physics nods. A handful of them are:
The original game is named Half-Life, and a major objective involves Freeman working with the Lambda Complex.Exp.The lower-case lambda is used to represent exponential decay; in other words, the half-life of radioactive materials.
Additionally, chapter names often allude to this through double meanings, such as "Surface Tension".
Reflecting Laser: The Tau Cannon / "Gauss". Technically a "hypervelocity projectile" weapon, but works like an insta-hit laser that reflects off any solid map surface at 45 degrees angle or less to the horizontal.
Remember the New Guy: Barney Calhoun, who was technically around and named before Half-Life 2, but never interacted with Gordon (although many characters who looked and sounded exactly like him did). A more blatant example of this is Dr. Magnusson in Episode Two, who definitely wasn't around before then, at all, and the scientists Barney helps get out in Blue Shift.
Amusingly, the Brick Joke about the microwave casserole only works because he didn't appear in the original Half-Life (at least, not with the same voice or model — see You ALL Look Familiar below).
A safer version of this is used in Episode Two to reach the rocket cache, using a grenade and a metal 'catapult' on hinges. The achievement is aptly named 'Gordon Propelled Rocket', which is also an inversion of 'RPG'.
Schmuck Bait: Early on, after the resonance cascade, you reach an elevator with a large warning sign next to it - "In Case Of Fire Do Not Use Elevators" - should you press the button, an elevator full of scientists will fall screaming to their doom (though if you don't press the button, the elevator will fall anyway once you break the door's glass to continue). (The developer who thought this up said that it worked both as a game element and as a message to other developers - "Enough with the d*mn button puzzles already.")
Sequence Breaking: The physics engine and stackable boxes allow clever players to bypass some of the challenges. There are three areas in "Nova Prospekt" where the player must use mounted turrets to repel the Combine. In two of those areas, it is possible to stack boxes to block some of the attack routes and, in the second, to escape to a more defensible position. Alternatively, a dedicated player may choose to bring along the turrets from each area to the next, giving you far more firepower than you'd normally have.
You must dodge Black Ops snipers and trip wire mines in Opposing Force... and snipe them back.
You also have to save Barney from Combine Snipers later in the game. This was supposed to happen multiple times in the beta.
While never performed by the player, Alyx takes this role twice, one time during each Episode, to your benefit.
Soft Water: Which saves you from massive damage a lot. The engine demonstrates this trope aggressively: custom maps use ankle-deep water to break several story falls all the time. Just don't jump into any water infested with parasites or that has broken electronics nearby, or it's instant death!
Swiss Army Weapon: Gordon Freeman's suit. Not only does it protect from dangerous hazards, it can block bullets, generate air, it has a flashlight, it can hold many weapons, allows Gordon to run faster, and has a scope.
Too Dumb to Live: Gordon sometimes does some incredibly stupid things, like deliberately entering a metal coffin right into Breen's hands. Twice. Breen even lampshades this.
A fair number of Black Mesa staff also succeed in getting themselves killed under blatantly stupid circumstances, such as running directly into obvious traps, while HECU and Black Ops soldiers can sometimes blow themselves up with their own grenades. While some of it is scripted, many instances can also be attributed to Artificial Stupidity.
Tortured Monster: The zombies are humans who have been turned into People Puppets and mutated by the parasitoid headcrabs attached to their heads. In the second game they can be heard screaming for help as they attack you.
Originally, Vortigaunts, who would gibber and only knew one English phrase: DIE!!
Headcrab zombies from the second game count, until you play their speech files backwards. Then you wish they were unintelligible. In the first game, they'd simple gurgle at you.
Unusable Enemy Equipment: Averted. Even if it's alive. Even if it tries to bite your face off. Also played straight with the Combine Sniper Rifle. Also, even though they are allies, not enemies, Alyx's Machine Pistol and Father Grigori's Winchester Rifle are unique to them.
Unwitting Pawn: Gordon Freeman, and how! Adrian Shephard is a close second.
Use Item: The same key is used to open doors, push buttons, talk to people, pick up things...
You travel to an alien factory. Of course the Big Bad's near.
In the sequel, once you enter the Citadel, you know there's going to be a boss at the top.
Video Games And Fate: The strict linearity and use of No Sidepaths, No Exploration, No Freedom in the series is a plot element as well as a gameplay device, reflecting how Freeman's actions are being controlled by the G-Man (who at one point boasts that he'd rather not offer Freeman "the illusion of free will").
A live wire dangling from the ceiling just zapped some headcrabs who were very close to a vent, after zapping the faceplate off that same vent. Where are you supposed to go in order to avoid going under the wire? Into said vent, of course!
There's a huge wall of double-stacked concrete barriers in your tram car's way. How do you proceed? By ramming the tram car right into it!
Climb into a hanging metal coffin that completely restricts your movements to make it into the enemy base? Sure. Do it again, even though the last one resulted in your weapons being confiscated and only dumb luck keeping you alive? Of course.
Locked in a room with a pit that has giant whirling fan blades the size of a bus and a ceiling that's boarded over. What to do? Jump out over the fan blades and turn into chunky salsa to get blown upwards, naturally!
The Watcher: The G-Man. It is also suggested that there are several other parties/individuals keeping track of the Combine's activities and are all trying to affect the outcome of the struggles on Earth:
Breen: ''How about it, Dr. Freeman? Did you realize your contract was open to the highest bidder?
Race X (the alien race from the Opposing Force expansion) is occasionally wondered about, but according to Marc Laidlaw, they don't matter to the HL Universe. Gearbox invented them to primarily experiment for future games of their own, and the minute Gearbox stopped making HL games, they vanished.
And none of the characters from Decay (in paticular the two main characters, Gina and Colette) have been seen since that game's ending.
Used again in Episode 2 by Kleiner when observing a eight-and-a-half pound weight difference in the rocket they're planning to launch. It's Kleiner's pet headcrab, Lamarr. And a garden gnome, if you did the achievement.
HECU grunts aren't that diverse. Neither are the citizens of City 17.
Headcrabs only seem to latch on to people wearing white shirts and blue jeans. Though this could be because most of the humans you see are forced to wear identical blue uniforms like in prison.
Continuing the tradition, they only latch to standard Overwatch Soldiers once they're out of Combine control. Metrocops and Combine Elites are perfectly safe. May be justified as higher ranked Combine achieve that rank by submitting to further cybernetic augmentation; there may not be enough human left for the Headcrabs to consider them proper hosts.
Zombie Apocalypse: Reconstructed. In Half-Life, zombies are created by alien crabs latching onto peoples' heads and taking control of the persons nervous system. The person effectively dies in the process, but remains animate because all the vitals that are necessary to live are in the crab, not the corpse. They're also still self-aware, just not in control.
Practically, this is what happened to nearly every single place after the Black Mesa Incident allowed headcrabs onto Earth and Combine started to use headcrab shells. There is no area in Half-Life 2 and its episodes where there would be no headcrab zombies or headcrabs wandering in search for a victim. The most direct example of this trope is Ravenholm, a town which was housing the refugees from City 17 before it was subjected to massive bombardment of headcrab shells and turned into Hell on Earth with a single survivor doing the work of saving the lost souls by the time Gordon shows up.