''Doom 3'' is a 2004 FirstPersonShooter, 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 more dark tone then the rest of the series, with aspects of SurvivalHorror.

An expansion pack called ''Resurrection of Evil'' was released in 2005, and takes place 2 years after the original story. In 2012, id Software released a ''BFG edition''.

The game was adapted into two novels by Matthew J Costello.

!Doom 3 contains examples of:

* AncientAstronauts: [[spoiler:Earth had been colonized by ancient Martians -- who seems to be humanoid creatures with the same size and width as Humans -- who teleported there to escape a demonic invasion. Some scientists ask themselves if the Martians are ancestors of Mankind.]]
* AntiFrustrationFeatures: If your health is lower than 10 and you go into the next level, the game will bump your health up to 25 percent to give you a fair chance.
* ArtificialBrilliance: The enemy's combat A.I. is very simple, but their path-finding A.I. is actually remarkably well-done; if you use an elevator or ladder to escape from a charging enemy, they can actually circle around the entire map to make their way to your new location. This is only noticeable if you go out of your way to toy with the A.I., however.
* AwesomeButImpractical: The laser sight that replaces the crosshair in ''Doom 3: BFG Edition'' if you're playing in 3D mode. It's a lazy, cheap hack that does ''not'' actually point at where your weapon actually fires, and also sways with your gun for further confusion. This is most noticeable in the first few levels, where you'll find it extremely difficult to get pistol headshots on zombies, or cr0wn the imp with one shotgun blast. Once you start getting automatic weapons it becomes tolerable, as you can just blast your way through the rest of the game without worrying too much about precise aim thanks to the increased ammo availability of the BFG edition.
* BadassBoast:
-->'''Swann:''' "This is the last time. I'm tired of running damage control every time he makes a mess."\\
'''Campbell:''' "Right. You're the control, and if that fails, ''I'm the damage.''"
* BittersweetEnding: The unnamed marine succeeds in sealing off Hell and survives, and is found by the subsequent reinforcements, but innumerable lives were lost beforehand.
* BlackoutBasement: Some of the areas.
* BodyHorror: Happens to [[spoiler:Sergeant Kelly]], who gets fused into a tank, and [[spoiler:Dr. Betruger]], who gets partially consumed by a demonic dragon.
* CutAndPasteEnvironments: It has been noted that many areas in the new "Lost Mission" campaign in ''Doom 3 BFG Edition'' are simply made up of rooms from vanilla ''Doom 3'' copy and pasted together.
* 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.
* DarkerAndEdgier: Definitely darker (har har), but it includes a storyline and several [=PDAs=] one can find to expand on how Hellish (har har) UAC became. It also introduces a lot more SurvivalHorror elements and contains jump scares, and makes combat a bit slower.
* DiegeticInterface: When the player is wielding a machinegun, the ammo counter disappears from the HUD and is replaced by a number displayed on the weapon itself.
* EarnYourHappyEnding: A common interpretation of the vague ending of ''Resurrection of Evil''. By the climax, every single person besides the 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 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.
* EmbeddedPrecursor: The Limited Collector's Edition of ''Doom 3'' 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.
* EverythingFades: In the first two ''Doom'' games the bodies of enemies stick around forever. In ''Doom 3'', demons disappear in a fizzly animation. This was probably to lighten the load on the game's engine and RAM usage by cutting down on rendered objects. Some mods do undo this and the bodies of humans and zombies generally remain, unless damaged to the point they disintegrate.
* ExplodingBarrels: Has a variant on these with the yellow toxic barrels. Once you shoot them, they simmer for a couple seconds before exploding (though they will explode automatically if caught in the splash of another explosive).
* FireAndBrimstoneHell: Hell is this, mixed with pulsating flesh and rivers of blood.
* IdiosyncraticDifficultyLevels
** ''Recruit'': damage taken reduced to 60%, less enemies;
** ''Marine'': normal damage taken, normal enemy rate;
** ''Veteran'': damage taken increased to 170%; slightly higher enemy rate;
** ''[[HarderThanHard Nightmare]]'': damage taken increased to ''three hundred percent'', more enemies, and your health constantly decreases to 25 points no matter what. Know that shiny Soul Cube you got at the start of the game? ''You '''will''' need it''.
* HyperspaceIsAScaryPlace: Teleporting will result in you seeing a [[spoiler:terrifying blood-tunnel filled with screams]].
* InfiniteFlashlight: The only upside of the torch is that it'll never run out of juice.
** TenSecondFlashlight: In the UpdatedRerelease, it becomes shoulder-mounted, but holds even less juice at a time than the headlamp in ''VideoGame/FirstEncounterAssaultRecon''. Fortunately, it also recharges very quickly, enough that flicking it on and off repeatedly means never staying fully in the dark.
* LaughablyEvil: The demons are, in an easter egg, this, believe it or not. In a hidden PDA, the demons try to instruct their fellows in how to invade:
-->"Virgin blood is best."\\
"Goat blood must be no older than 3 days."\\
"Entrails must be removed and apportioned either before death, or no later than 30 min."\\
"Candles must be sorted by tallest in back to shortest in front - never the other way around!"\\
"Most important - pentagrams must be drawn from the center to the outside and left to right."
* LifeDrain: When the Soul Cube's flung, it kills the demon and transfers all of its remaining life energy to you. Goes well with the lack of medkits late in the game.
* LimitedSpecialCollectorsUltimateEdition: The Limited Collector's Edition on the Xbox [[EmbeddedPrecursor includes the two previous games]]. It also added a ''second'' secret level to the first episode in ''Ultimate Doom'' and another secret level in ''Doom II''. It also includes an slideshow of concept art, an episode of Creator/{{G4|TV}}'s ''Icons'' on id Software, and interviews with the developers.
* MadScientist: Dr. Malcolm Betruger, to [[spoiler:literally diabolic levels]].
* MeaningfulName: The name of Dr. Betruger [[spoiler: means something along the lines of "scammer" in German. They probably intended it to be more like "traitor", but that would be "Verräter."]]
* MeatMoss: Some areas are covered with, for lack of a better word, flesh masses that look like turds. If you shoot them, they sound like steel.
* MedievalStasis / SchizoTech: A very strange example. It's 2145, humanity has an established base on Mars, has mastered plasma technology, and is foraying into the science behind atomic structure (the MFS Compactor comes to mind) and teleportation... yet:
** The most commonly found storage medium is a square-foot disk with capacity for only a few minutes of video and/or audio.
** Security forces lack any kind of enhanced vision, being forced to rely on hand-held flashlights[[note]]granted, the [[InfiniteFlashlight static transfer power supply]] is an advancement, but still[[/note]] (armor-mounted in ''BFG Edition'') with very bad quality reflectors full of artifacts and dark spots.
** All projectile-based weapons seem to use '''black powder''' given ''just how much smoke'' they produce per shot.
** All UAC workers must use a standard issue PDA that is clunkier and less versatile than most of the cheapest tablets you can find in 2012.
* MookMaker: The Archviles, not limited by the number of corpses. Mostly because of EverythingFades.
* OnlySixFaces: Only has a handful of faces for the various human [=NPCs=], which are re-used frequently. This is most noticeable in the opening ScenicTourLevel, where you can find two guys with the exact same head standing in the same room.
* OneWingedAngel: By the end of ''Doom 3'', [[spoiler:Betruger]] is transformed into a demonic dragon. In ''Resurrection of Evil'', [[ThatOneBoss he puts up a hell of a fight with his new powers]].
* RegeneratingHealth: Inverted in [[HarderThanHard Nightmare]] difficulty, where your health constantly decreases by five points every five seconds until it hits 25.
* RidiculousFutureSequelisation: A PDA message says "The new Quake-43 game blows my mind."
* ScenicTourLevel: Unlike most examples, they give you a gun and even allow you to murder your co-workers even ''before'' things go to hell.
* SequenceBreaking: Memorizing some of the security codes can do anything from unlocking powerful weapons early to circumventing an entire PDA hunt.
* TheStoic: The marine. Never shows any form of emotion on his face, even fear, just frowns when new sorts of monsters appear. The only time he shows fear is when he meets the Cyberdemon.
* StupidEvil: Dr. Malcolm Betruger, who apparently has no actual motive for attempting to transform Earth into Hell and its people into screaming demon-fodder. It is implied, however, that he has been possessed or is in some way controlled by the demons. The novels indicate he was an ordinary scientist who was subject to MoreThanMindControl, alternatively ''The Lost Mission'' campaign indicates he always had an obsession with the occult and was offered ultimate power by the demons in exchange for Earth.
* TeleporterAccident A PDA Audio entry details a lab monkey being split in half. Literally. The upper half went there and the lower half stayed behind.
* UniqueEnemy: In the second level you encounter a "fast zombie" in the infirmary. It can run almost as fast as you can, and would have made a pretty challenging enemy if encountered in large numbers. The one you see in the infirmary is the only one in the entire game, with all other zombies being the standard "slow shambling" type.
* VideoGameCrueltyPotential: All of the survivors you meet can be straight up murdered either for giggles or to charge the [[HarderThanHard nightmare mode]] item; you can even do this ''before'' the demonic invasion begins. In fact, this is actually a ''smart'' thing to do, as many of the civilians in the intro sequence become zombies. One of the cruelest is activating a machine that will strip or melt the flesh off a scientist's bones, complete with a few seconds of horror and terror as the scientist realizes what is about to happen to him. In the BFG Edition, this one gets you an achievement.
* VillainBeatingArtifact: The original version requires that the player use the Soul Cube to take care of the final boss Cyberdemon. This was changed both in later patches of single-player mode and in co-op mode.