History VideoGame / Doom3

In January 2021, an unofficial port made the game fully playable in VR on the Platform/OculusQuest 2. For licensing reasons, the port requires the user to sideload assets from the PC version. The VR port is based on an earlier unofficial port that moved the game into the Quest's native Android operating system.

* NoOSHACompliance: Deconstructed. Even during the friendly introduction to the facility, numerous people complain about the dangerous conditions and complete lack of safety standards in their working environment. Somewhat lampshaded by the automatic announcement that the UAC "cares about the safety of its employees". There's a room that is sealed off because radiation levels are too high. In order to pass through this room, you need to play a minigame in which you pick up barrels of toxic waste with a crane and drop them into an incinerator. This is ironically the most OSHA-compliant room in the entire game. The EPA (Environmental Protection Agency), on the other hand, would probably want a word with you.
** This trope is also Justified, as several [=PDA=]s do mention safety measures existing, and failing for unexplainable reasons, because of demonic tampering.

* CanonDiscontinuity: Notably, ''VideoGame/DoomEternal'' excluded this game in its massive CanonWelding of the ''Doom'' franchise (which included the first two games, ''VideoGame/Doom64'', and the 2016 game). Yes, the Soulcube is in the reboots as an Easter Egg, but it's never directly explained or powered.

* AdaptationalWimp: Elliot Swann in the novelizations. Game!Swann is a hardass who willingly walks into the face of death, while book!Swann behaves like an expy of [[Film/JurassicPark Donald Gennaro]].

In 2012, id Software released the ''[[UpdatedRerelease BFG Edition]]'' for Platform/{{Xbox 360}}, Platform/PlayStation3, and PC, which includes a remastered and retooled version of ''Doom 3'' (with an armor-mounted flashlight replacing the original's controversial flashlight system, brighter environments, faster player movement, slower weapons, and more ammo), whereas Doom 3 required a fan-made mod for the PC version to allow a weapon-mounted flashlight. ''BFG Edition'' also comes bundled with ''Resurrection of Evil'', an all-new mini-campaign called ''The Lost Mission'' (consisting mostly of cut content), [[EmbeddedPrecursor plus]] ''The Ultimate Doom'' and ''VideoGame/DoomII'', as well as the ''No Rest for the Living'' expansion that was developed for ''Doom II''[='=]s Platform/XboxLive release, making for a very packed ''Doom'' experience. It was later ported to Platform/{{Android}} for Nvidia Shield and Google Play Store in 2015. Another standalone re-release based on the ''BFG Edition'', simply titled ''Doom 3'', was handled by Panic Button and was released in 2019 for Platform/XboxOne, Platform/PlayStation4, Platform/NintendoSwitch, and PC through Bethesda.net, Microsoft Store, and Epic Games Store along with the updated ports of ''Doom'' and ''Doom II''.

* BittersweetEnding: The unnamed marine succeeds in sealing off Hell and survives, and is found by the subsequent reinforcements albeit exhausted and perhaps even traumatized, but innumerable lives were lost beforehand to the point that the marine is implied to be the SoleSurvivor; [[spoiler: even if you spared him, Swann bleeds out from his grievous injuries.]] The Lost Mission retroactively implies there to be more survivors off-screen, but a handful at best. Also, [[spoiler: Betruger [[KarmaHoudini got away]] and became the leader of Hell itself as the [[OurDragonsAreDifferent Maledict]], setting up a SequelHook for ''Resurrection of Evil'' to conclude.]]

* EmbeddedPrecursor:
** The ''Doom 3''[='s=] Limited Collector's Edition and ''Resurrection of Evil'' on the original Xbox includes the original ''Doom'' and ''Doom II''; the latter also includes the ''Master Levels of Doom II''. The ''BFG Edition'' also includes the first two ''Doom'' games.

** ''Lost Mission'' has Doctor Richard Meyer in this role.

* NoSidepathsNoExplorationNoFreedom: {{Downplayed}}. Compared to the abstract layouts of the classic games (including ''VideoGame/Doom64''), the ''Doom 3'' levels are pretty linear, but they still have plenty of secrets, and sidepaths, especially with the optional vaults and P.D.A's. The Hell levels, especially in ''The Lost Mission'', are a bit closer to the level design of the classic games and can easily ''feel'' non-linear on a first-time playthrough.

* UnusableEnemyEquipment: Former humans' guns can be picked up for ammo, as they're the same as yours (even the Commando's chaingun). In fact, the way you get the machinegun if you didn't open the locker at the end of the second level is to grab one off a Z-sec enemy. However, you can't pick up wrenches or additional flashlights from civilian zombies that wield them.
* UpdatedRerelease: The ''BFG Edition'' features remastered versions of ''Doom 3'', the ''Resurrection of Evil'' expansion pack, and a new set of levels cut from the original game in the form of ''The Lost Mission'', all with improved lighting and rendering, support for 3D TV displays, native ultrawide and high refresh rate support (the original game needed a fan-made patch for ultrawide resolutions and doesn't natively support refresh rates above 60 Hz; a later update in 2023 for the Steam and Microsoft Store versions raises the limit to 240 Hz), a new (though optional) checkpoint system, re-tooled gameplay elements (e.g. less enemies to battle, shoulder-mounted flashlight, more plentiful ammo), and achievement/trophy support. This also bundles the HD ports of ''The Ultimate Doom'' and ''Doom II: Hell on Earth'', which also gives PC players the ability to play the previously console-exclusive ''No Rest for the Living'' episode for ''Doom II''.

* DownerBeginning: ''The Lost Mission'' starts where Bravo Team was ambushed by demons from the main campaign, followed by a marine's lifeless body being dragged through a blood-soaked duct. The fan-made campaign port for the original ''Doom 3'' expands on the opening where the Bravo Marine who was dragged through the duct finds mysteriously himself alive despite being dragged around by a demon, then the game proceeds from there.

* UnbrokenFirstPersonPerspective: Unlike the base game and ''Resurrection of Evil'', the Lost Mission never leaves the player character's perspective after the opening cutscene.

* WhoForgotTheLights: The game is rather infamous for being very dark, mainly to show off the game engine's ability to render complete pitch-black darkness. In universe, it's explained by a combination of the UAC cutting corners on lighting and teleporter experiments wreaking havoc with the power grid.
* WombLevel: Several of the hellish sections are covered in living flesh.
* WrongGenreSavvy: Sergeant Kelly seems to think that the invasion needs to be treated like any other enemy force, and commands Doomguy to send a transmission for reinforcements. [[spoiler:Too bad that that is exactly what [[BigBad Dr. Betruger]] wants, so as to use those ships to have the demons invade Earth. It ultimately doesn't matter because he would have sent the transmission anyway if you hadn't.]]
* YouDontLookLikeYou: The Demons only somewhat resemble their counterparts from the earlier games in the series (the game is a reboot for its series, so it's justified).

** ''[[https://www.doomworld.com/forum/topic/117191-dbp28-fear-and-loathing/ DBP 28: Fear and Loathing]]'' is a short campaign inspired by ''Doom 3'' in the original. But unlike ''Ultimate Super Doom 3'' that needs an advanced source port[[note]]specifically [=GZDoom=][[/note]] and advanced scripting thereof to work, ''Fear and Loathing'' -- other than needing to remove static limits -- runs entirely on the original id Tech 1 engine. Even the flashlight works as a hack

''Doom 3'' (stylized as ''Doom³'') is a 2004 FirstPersonShooter in the ''Franchise/{{Doom}}'' franchise, developed by Creator/IdSoftware and released for both the PC and Xbox. Despite its name, it is not a sequel to the original ''VideoGame/{{Doom}}'' games, but rather it is a reboot. It has a darker tone than the rest of the series, with aspects of SurvivalHorror.

In 2012, id Software released the ''[[UpdatedRerelease BFG Edition]]'', which includes a remastered and retooled version of ''Doom 3'' (with an armor-mounted flashlight replacing the original's controversial flashlight system, brighter environments, faster player movement, slower weapons, and more ammo), whereas Doom 3 required a fan-made mod for the PC version to allow a weapon-mounted flashlight. ''BFG Edition'' also comes bundled with ''Resurrection of Evil'', an all-new mini-campaign called ''The Lost Mission'' (consisting mostly of cut content), [[EmbeddedPrecursor plus]] ''The Ultimate Doom'' and ''VideoGame/DoomII'', as well as the ''No Rest for the Living'' expansion that was developed for ''Doom II''[='=]s Platform/XboxLiveArcade release, making for a very packed ''Doom'' experience. Another standalone re-release based on the ''BFG Edition'', simply titled ''Doom 3'', was handled by Panic Button and was released in 2019 along with the updated ports of ''Doom'' and ''Doom II'' for the 8th generation of consoles and PC.

* CoOpMultiplayer: The Xbox port of the game and ''Resurrection of Evil'' features two player co-op for their respective campaigns via system link, LAN connection, or Xbox LIVE, while the classic ''Doom'' games can also be played through split-screen with up to four players. The PC version's campaign is single-player only, but the original does have mods such as [=LibreCoop=] that provides this feature for the base game and its expansion pack as well as the ability to add compatibility for custom maps.

* ContextSensitiveButton: The button that normally fires your weapon becomes an "activate" command when you are near an active panel and your aiming reticule is inside it.

* CoversAlwaysLie: The artwork for ''The Lost Mission'', which was later reused for the 2019 re-release of ''Doom 3'' and Steam Library UI artwork for ''Doom 3: BFG Edition''. It shows an armored space marine that looks nothing like the one featured in the game proper, [[GunsAkimbo dual-wielding guns]] (which you can't do in the game), while a towering, stocky demon that never existed in the game itself is behind him. The demon is probably supposed to be the Guardian of Hell, which is the FinalBoss of ''The Lost Mission'', but it looks more like a blend of that and a Mancubus.

** Killatomate's Realistic Weapons mod tweaks how weapons handle in the original ''Doom 3'' and ''Resurrection of Evil'' and making them feel, well, [[ExactlyWhatItSaysOnTheTin realistic]]. For example, the pistol becomes semi-automatic with proper recoil and spread between shots, the shotguns have been rebalanced spread and damage output with readjusted reloading, and the chaingun now has a retuned recoil, spread, velocity, and reloading animation. The sound effects also have been replaced with sounds from real-life guns for many of the weapons of the game.

* InfiniteFlashlight: The only upside of the torch is that it'll never run out of juice.

** The walls in Central Processing: Processing Distribution Center look very similar to the COMPTALL texture from the original Doom game.

* ShowsDamage: Most enemies and [=NPCs=] can bleed and leave blood splotches on their faces or body from where they are hit/shot.

* AchievementSystem: Implemented into the ''BFG Edition'', which features 50 achievements on the Xbox 360 version, 65 achievements on the PC version, and 66 trophies on the Platform/PlayStation3 version. These achievements range from "clear ''Doom 3'' under X difficulty" to "find a particular item in the game" to "killing players in a specific way in multiplayer".

* CanonDiscontinuity: Notably, ''VideoGame/DoomEternal'' excluded this game in its massive CanonWelding of the ''Doom'' franchise (which included the first two games, ''VideoGame/Doom64'', and the 2016 game). Yes, the Soulcube is in the reboots as an easter egg, but it's never directly explained or powered.

** The ''Doom 3'' Limited Collector's Edition and ''Resurrection of Evil'' on the original Xbox includes the original ''Doom'' and ''Doom II''. The latter also includes the ''Master Levels of Doom II''.
** The ''BFG Edition'' also includes the first two ''Doom'' games.

** ''Doom 3: Enhanced Edition'' is a mod that aims to give the game and its expansion packs some quality-of-life improvements, visual and audio touch-ups, and a few gameplay tweaks without deviating from the original gameplay.
** ''dhewm³'' is a source port of ''Doom 3'' that provides bugfixes, support for modern resolutions without editing configuration files or using the developer console, restore EAX support for 3D and surround sound capabilities through [=OpenAL=], controller support through [=SDL2=], and improved support for 64-bit operating systems (though requires compiling from source code). Modding support, however, is limited to non-DLL based mods unless the mod's developer can port it to the new engine.
** ''[=CstDoom3=]'' is an engine overhaul of ''Doom 3'' that adds new options, quality-of-life improvements, optional gameplay tweaks, bugfixes, and implements Carmack's Reverse to improve performance with the game's shadow rendering. It also has a version for the ''BFG Edition'' that gives players the ability to restore some of the cut content from the original game, the option to re-instate the original flashlight mechanics or use a hybrid of the two, bring the game's ammo distribution back to the original values, and a built-in AchievementSystem.

** The [=UltimateHD=] mod for the ''BFG Edition'', which not only improves some of the game's visuals and effects, it also readjusts some gameplay elements, gives enemies [[ArtificialBrilliance new AI behaviors]] (e.g. Imps will leap away from the player's line of sight), and retools the game's weapons and how they handle.

* TooAwesomeToUse: The Soul Cube does enough damage to one-shot any non-boss monster, refills your health up to 100, and recharges every 5 kills (it even helpfully says "use us" once it's charged). While you could theoretically just use it on every 5th monster you fight, most people still save it for things like [[BossinMookClothing Archviles]] and [[DegradedBoss Hell Knights]]. In an interesting twist, it is the only way to actually hurt the [[FinalBoss Cyberdemon]], although you are given an endlessly respawning stream of low-end {{Mooks}} so you can refill the cube.

''Doom 3'' (stylized as ''Doom³'') is a 2004 FirstPersonShooter in the ''Franchise/{{Doom}}'' franchise, developed by Creator/IdSoftware and released for both the PC and Xbox. Despite its name, it's not a sequel to the original ''VideoGame/{{Doom}}'' games, as much as a reboot. It has a darker tone than the rest of the series, with aspects of SurvivalHorror.

An ExpansionPack called ''Resurrection of Evil'' was released in 2005, and takes place two years after the original story. In 2012, id Software released the ''[[UpdatedRerelease BFG Edition]]'', which includes a remastered and retooled version of ''Doom 3'' game (with an armor-mounted flashlight replacing the original's controversial flashlight system, brighter environments, faster player movement, slower weapons, and more ammo), whereas Doom 3 required a fan-made mod for the PC version to allow a weapon-mounted flashlight. ''BFG Edition'' also had an all-new mini-campaign called ''The Lost Mission'' (consisting mostly of cut content), [[EmbeddedPrecursor plus]] ''The Ultimate Doom'' and ''VideoGame/DoomII'', as well as the ''No Rest for the Living'' expansion that was developed for ''Doom II''[='=]s Platform/XboxLiveArcade release, making for a very packed ''Doom'' experience. Another standalone re-release of the ''BFG Edition'', simply titled ''Doom 3'', was handled by Panic Button! and released in 2019 along with the updated ports of ''Doom'' and ''Doom II'' for the 8th generation of consoles and PC.

* BonusFeatureFailure: The inclusion of the first two ''Doom'' games has retroactively became this, at least on PC when compared to their newer Unity ports after they became available on PC in 2020. While the ''BFG Edition''[='=]s version of ''Doom'' and ''Doom II'' runs at a higher resolution and provides a legitimate way to play the ''No Rest for the Living'' on PC, it also has a persistent smoothing filter applied on the screen, slower audio at a lower bitrate with the randomly pitch shifted sounds always enabled, is locked to 30 FPS, is {{bowdlerise}}d[[labelnote:*]](the medkits had the red crosses replaced with a pill and the ''Wolfenstein 3D'' levels are heavily censored)[[/labelnote]], and the Nightmare! difficulty broke the fast enemies, whereas the Unity ports offers a crispier old-school appearance with the ability to play in 16:9 widescreen, has improved audio quality with the ability to turn off randomly pitch shifted sounds, can run up to 60+ FPS, has fewer censorship changes[[labelnote:*]](the medkits uses green crosses instead of pill symbols and the alterations in the ''Wolfenstein 3D'' levels are downplayed, making the levels look more akin to the Super Nintendo version of that game)[[/labelnote]], restores the fast enemy speed of the Nightmare! difficulty, and offers the ability to play ''No Rest for the Living'' along with ''VideoGame/FinalDoom'' and ''VideoGame/{{Sigil}}'' among many other curated mods all in one place. This is not an issue with the 8th generation console releases of ''BFG Edition'' since it already stripped out the classic ''Doom'' games in favor of the newer Unity ports.

** It is possible to obtain normally unobtainable [=PDAs=] from certain [=NPCs=] by killing them, like some of the workers in "Mars City Underground". These [=PDAs=] contain information like any normal obtainable PDA.

** When the player teleports to Hell late in the game, they lose all of their weapons and ammo and need to scavenge replacements. Said replacements just happen to be the ''Doom 3'' equivalents of the original lineup.[[note]]fists, chainsaw, pistol, shotgun, chaingun, plasma gun, rocket launcher, BFG. Technically, the Soul Cube is also acquired in Hell, but it isn't usable until returning to Mars.[[/note]] The player also have unlimited stamina in Hell, allowing the Marine to sprint as much as he want not unlike the original ''Doom''.

* UpdatedRerelease: The ''BFG Edition'' features remastered versions of ''Doom 3'', the ''Resurrection of Evil'' expansion pack, and a new set of levels cut from the original game in the form of ''The Lost Mission'', all with improved lighting and rendering, support for 3D TV displays, native ultrawide and high refresh rate support (the original game needed a fan-made patch for ultrawide resolutions and doesn't natively support refresh rates above 60hz), a new (though optional) checkpoint system, re-tooled gameplay elements (e.g. less enemies to battle, shoulder-mounted flashlight, more plentiful ammo), and achievement/trophy support. This also bundles the HD ports of ''The Ultimate Doom'' and ''Doom II: Hell on Earth'', which also gives PC players the ability to play the previously console-exclusive ''No Rest for the Living'' episode for ''Doom II''.

* VoiceOfTheLegion: The villain Malcolm Betruger, who has somehow become corrupted by the demons of Hell, spends the second half of the game taunting the player about how Hell will reign, how your soul will be his etc, in a typically villainous, nasal voice. However, when you reach the final boss at the end, you suddenly hear Betruger again: ''"So you made it this far?"'' in a cavernous, echoing roar. It's quite clear that something rather fundamental has changed about Dr Betruger, but we don't learn what until the final scene in the game. The souls which created the Soul Cube also have this.

* ShortRangeShotgun: The shotgun and Super Shotgun. Though still short ranged, the Super Shotgun is actually a bit more accurate than the regular shotgun since there's a larger central grouping of shot.

* EarnYourHappyEnding: A common interpretation of the vague ending of ''Resurrection of Evil''. [[spoiler:By the climax, every single person besides the Engineer Marine and Dr. [=McNeil=] is implied to be dead. [=McNeil=] orders the marine to shut down all the core systems in Phobos Labs, [[HeroicSacrifice including the life support system]], to power up the old teleporter so he can reach the old Delta Labs and eventually Hell itself to return the artifact and stop the invasion. After battling his way through the demons, the Engineer Marine reaches Betruger/Maledict and is mortally wounded in the battle, but manages to destroy him with the artifact using his last ounce of strength. As the screen fades to white, [=McNeil=]'s voice can be heard saying "Marine, welcome home", implying that the two are in a better place for their sacrifice.]]

** Erebus Facility in general has several thematics to it: an excavation site similar to Caverns, Artifact Storage inspired by Site 3, Erebus Control having similarities with Mars City Underground, Erebus Research and Erebus Station both based on Recycling Plant and so on.

* TennisBoss: The first boss is one of these. For that matter, you can kill virtually every other (non-boss) enemy in the game with ''one hit'' in this manner.

An ExpansionPack called ''Resurrection of Evil'' was released in 2005, and takes place two years after the original story. In 2012, id Software released the ''[[UpdatedRerelease BFG Edition]]'', which includes a remastered and retooled version of ''Doom 3'' game (with an armor-mounted flashlight replacing the original's controversial flashlight system, brighter environments, faster player movement, and more ammo), whereas Doom 3 required a fan-made mod for the PC version to allow a weapon-mounted flashlight. ''BFG Edition'' also had an all-new mini-campaign called ''The Lost Mission'' (consisting mostly of cut content), [[EmbeddedPrecursor plus]] ''The Ultimate Doom'' and ''VideoGame/DoomII'', as well as the ''No Rest for the Living'' expansion that was developed for ''Doom II''[='=]s Platform/XboxLiveArcade release, making for a very packed ''Doom'' experience. Another standalone re-release of the ''BFG Edition'', simply titled ''Doom 3'', was handled by Panic Button! and released in 2019 along with the updated ports of ''Doom'' and ''Doom II'' for the 8th generation of consoles and PC.

Just like in the original game, you're a {{n|oNameGiven}}ameless, [[HeroicMime silent]], badass SpaceMarine, who has just been assigned to the Union Aerospace Corporation's base on UsefulNotes/{{Mars}}. Upon arriving and reporting to your sergeant, you are given your first task: find a scientist who has gone missing in the old communications facility. At first glance, the place and assignment seem [[NothingExcitingEverHappensHere as dull as dirt]], but as you speak to other marines and workers during your search, the creepier things start to seem. Many employees seem frightened and paranoid, and then there's the fact that the whole reason you were assigned here in the first place was to replace another Marine who died during an operation. You also overhear some rather suspicious conversations held by a high-ranking UAC lawyer and his lackey, and shadiest of all, the creepy and mysterious director of research [[BigBad Dr. Malcolm Betruger]], who promises that "amazing things will happen". By the time you find the missing scientist, things are already creepy enough, but then Hell literally breaks loose, and you find yourself as one of the few people left alive in a base rapidly being overrun with grotesque monsters, reanimated and murderous former humans, and otherwordly, demonic imagery. It's up to you find and stop the source of the invasion, locate and aid any fellow survivors, and fight to stay alive.

An ExpansionPack called ''Resurrection of Evil'' was released in 2005, and takes place two years after the original story. In 2012, id Software released the ''[[UpdatedRerelease BFG Edition]]'', which includes a remastered and slightly retooled version of the original ''Doom 3'' game (with an armor-mounted flashlight replacing the original's controversial flashlight system, and more ammo), whereas Doom 3 required a fan-made mod for the PC version to allow a weapon-mounted flashlight. ''BFG Edition'' also had an all-new mini-campaign called ''The Lost Mission'' (consisting mostly of cut content), [[EmbeddedPrecursor plus]] ''The Ultimate Doom'' and ''VideoGame/DoomII'', as well as the ''No Rest for the Living'' expansion that was developed for ''Doom II''[='=]s Platform/XboxLiveArcade release, making for a very packed ''Doom'' experience. Another standalone re-release of the ''BFG Edition'', simply titled ''Doom 3'', was released in 2019 along with the updated ports of ''Doom'' and ''Doom II'' for the 8th generation of consoles and PC.

* DamnYouMuscleMemory: ''Doom 3: BFG Edition'' maps sprinting to the left thumbstick button like most contemporary shooters. But while those shooters only require you to tap the button once, in this game you have to hold it down to sustain the sprint. This can also be confusing for those that have played the original Xbox version where the sprint button is mapped to the left trigger. On the PC version of ''BFG Edition'' at least, players can remap their controls.

** When the player teleports to Hell late in the game, they lose all of their weapons and ammo and need to scavenge replacements. Said replacements just happen to be the ''Doom 3'' equivalents of the original lineup[[note]]fists, chainsaw, pistol, shotgun, chaingun, plasma gun, rocket launcher, BFG. Technically, the Soul Cube is also acquired in Hell, but it isn't usable until returning to Mars[[/note]].
** The ancient tablets depicting the battle between the Martians and demons is the cover art of the original Doom, except Doomguy is carrying the Soul Cube rather than a submachine gun.

* ArtShift: The one speaking role character you encounter, Dr. Meyers, is motion-captured and far smoother in animation than anything in the main two campaigns that used hand-animated keyframes by comparison.

* DownerBeginning: The Lost Mission starts where Bravo Team was ambushed by demons from the main campaign, followed by a marine's lifeless body being dragged through a blood-soaked duct.

* WhatHappenedToTheMouse: The ending cutscene, as well as the opening cutscene of ''Resurrection of Evil'', establish that [[spoiler:the Marine was the one and only survivor of the invasion, which leads one to wonder what happened to the small handful of other survivors that you find throughout the game, most of whom who were still alive and well at the time you left their company.]]

* VideoGameDemake: [[https://doom.fandom.com/wiki/Ultimate_Super_Doom_3 Ultimate Super Doom 3]], which brings the weapons and monsters from ''Doom 3'' into the classic ''Doom'' games.

* EmergencyWeapon: In addition to retaining the fists and the flashlight, the expansion adds the Grabber, which can be used to grab barrels, crates, most enemy projectiles and even some small enemies themselves, and fire them back at the sender, and in addition its Soul Cube analogue gives the same bonuses as the above-mentioned power-up from the base game, depending on how many of the Hunters you've killed.

* IntsUpToYou: The game puts you in the shoes of a marine who is transferred to Mars for unknown reasons. Everybody on Mars -- besides a handful of marine teams and the other four main characters -- is quickly wiped out in the breakout of an ensuing demonic invasion. The marine squads and two of the main characters all fail to do anything of value (of the remaining two, [[spoiler:one gets corrupted into evil and the other is the BigBad]]); the player alone is responsible for stopping the invasion.

* DarkWorld: The expansion has a NonPlayerCharacter outright state that the [[spoiler:Delta Labs area is phasing in and out of the AnotherDimension, {{Hell}},]] creating a more tangible Dark World where the two intersect. In fact, the penultimate level has you going through previously-visited areas as reality constantly shifts back and forth every couple of seconds.

* EarnYourHappyEnding: A common interpretation of the vague ending of ''Resurrection of Evil''. [[spoiler:By the climax, every single person besides the Engineer Marine and Dr. [=McNeil=] is dead. [=McNeil=] orders the marine to shut down all the core systems in Phobos Labs, [[HeroicSacrifice including the life support system]], to power up the old teleporter so he can reach the old Delta Labs and eventually Hell itself to return the artifact and stop the invasion. After battling his way through the demons, the Engineer Marine reaches Betruger/Maledict and is mortally wounded in the battle, but manages to destroy him with the artifact using his last ounce of strength. As the screen fades to white, [=McNeil=]'s voice can be heard saying "Marine, welcome home", implying that the two are in a better place for their sacrifice.]]
* EmergencyWeapon: In addition to retaining the fists and the flashlight, the expansion adds the Grabber, which can be used to grab barrels, crates, and even most enemy projectiles and fire them back at the sender, and in addition its Soul Cube analogue gives the same bonuses as the above-mentioned power-up from the base game, depending on how many of the Hunters you've killed.

** Phobos Labs are a mixture of Alpha and Delta Labs facilities, plus some elements of Recycling Plant thrown in.

* SuspiciousVideogameGenerosity: In the final room, before the final boss, you are treated with a lot of items and powerups. Randomly throughout the game you can use the souls of corpses to give yourself invulnerability/damage buff/speed increase, and you find these corpses littering most of the stages, however you find almost six in one place, which is three more than you could possibly hold.

* NoGearLevel: Shortly after deciding whether to call the fleet or not, the main character is teleported to Hell and loses all his weapons. Then you're fighting the big monsters you've been saving rocket shells for with a shotgun and dead ends. When you return to Mars, you lose your weapons again (except for the Soul Cube), but thankfully, you reacquire most of your arsenal right at the start of your return.

* BackFromTheBrink: The game puts you in the shoes of a marine who is transferred to Mars for reasons unknown. Everybody on Mars is quickly wiped out in an ensuing demonic invasion (much like the first game) besides a handful of marine teams (Who quickly get taken out ''in a cutscene'') and the other 3 main characters plus the mastermind behind everything. The player is basically responsible for stopping the invasion.
* BadassBoast:

* JigsawPuzzlePlot: Provided with the audio logs, video disks, and emails. Plus, it also makes players actually get the plot by placing important information such as codes with the plot.
* JumpScare: Happens often -- in particular, Imps love to crouch down behind doors and around corners, just waiting for you to come by so they can lunge at you.
* KingMook: Vagary, the Trite Queen, serves as a Queen Mook for the knee-tall spiders that creep from viaducts and other small tunnels to ambush the main character.
* {{Knockback}}: Shotgun Z-Secs and Pinky Demons have both deliverable sizable knockback, the former bordering on BlownAcrossTheRoom, and can result in {{stunlock}}.

* BackFromTheBrink: The game puts you in the shoes of a marine who is transferred to Mars for reasons unknown. Everybody on Mars is quickly wiped out in an ensuing demonic invasion (much like the first game) besides a handful of marine teams (Who quickly get taken out ''in a cutscene'') and the other 3 main characters. The player is basically responsible for stopping the invasion.