- (0,0) respawning bug
- 10 Sectors
- 1337 Guns
- 16-bit
- 1994 level
- 1 Monster
- 2002: A Doom Odyssey
- 2 Sectors
- 30,000 Levels
- 30nm4949
- 30uv1441
- 30uv1617
- 32-bit
- 32X Doom Development
- 32in24 (series)
- 3DGE
- 3DO
- 3D floor
- 3D middle texture
- 4 shotgun shells
- 8-bit
- 99 Ways to Die
- A. Chang
- AASTINKY
- ACC
- ACE Team
- ACS
- ACS mini game
- ARC Carrier
- ARC Complex
- ARC Mech
- ATB Doom
- Abaddon (Doom II RPG)
- Abraham Peters
- Accuracy Stat
- Accuracy Upgrade
- Achievement
- Acolyte
- Action Doom
- Action Doom 2: Urban Brawl
- Adam Berneche
- Adam Hegyi
- Adam Williamson
- Adam Windsor
- Adamante Limes
- Add-ons
- Adding custom music
- Adding custom sounds
- Adding custom sprites
- Adding custom textures
- Administration
- Administration: Union Aerospace Corporate Division
- Adolf Hitler
- Adolf Vojta
- Adrenaline
- Adrian Carmack
- Advanced Research Complex
- Advanced Research Complex (Doom VFR)
- Advanced lift design techniques
- Afrit
- Agaddon Hunter
- Aggadons
- Ahzrak
- Aimbot
- Alan Dorweiler
- Albert Gallatin
- Alex Mayfield (AlexMax)
- Alex Meyers (Apothem)
- Alex Pritchard (pritch)
- Alex St. John
- Alexander S. (Eternal)
- Alexo
- Alien Vendetta
- Aliens Doom 3 - Aliens versus Predator
- Aliens TC
- Aliens versus Predator Theme Patch
- Aligning textures
- All Hell is Breaking Loose
- All secrets and stats increases in Strife: Veteran Edition
- Allen Rhodes
- Alpha Labs
- Alpha Labs - Sector 1: Union Aerospace Science Division
- Alpha Labs - Sector 2: Union Aerospace Science Division
- Alpha Labs - Sector 3: Union Aerospace Science Division
- Alpha Labs - Sector 4: Union Aerospace Science Division
- Alpha Soul
- Ambient
- American McGee
- Amiga
- Ammo
- Ammo Satchel
- Amulet of Warding
- Amulets & Armor
- Amulets & Armor thing types
- Ancestral
- Anders Johnsen
- Andreas Kren (Anthe)
- Andrew Apted
- Andrew Bassett (AndrewB)
- Andrew Benson
- Andrew Chin
- Andrew Fernie (Ninja of DooM)
- Andrew Stine (Linguica)
- Andrey Budko (entryway)
- Android
- Andy Kempling (aurikan)
- Andy Olivera
- Andy Stratton
- Angle
- Animated flat
- Animated wall
- Anna Kang
- Anomaly Report
- Anthony Czerwonka (Adelusion)
- Anthony Garza
- Anthony Soto (Swedish Fish)
- Apocalypse
- Apogee Software
- Apollyon
- Arachnotron
- Arachnotron/Doom: The Dark Ages
- Arachnotron/Doom 64
- Arachnotron/Doom Eternal
- Arachnotron/Doom II
- Arachnotron/Doom II RPG
- Arc of Death
- Arcade
- Arch-vile
- Arch-vile/Doom (2016)
- Arch-vile/Doom 3
- Arch-vile/Doom Eternal
- Arch-vile/Doom II
- Arch-vile/Doom RPG
- Arch-vile jump
- Architecture
- Argent Axe
- Argent Caches
- Argent D'Nur
- Argent D'Nur (level)
- Argent Energy
- Argent Energy Cell
- Argent Energy Tower
- Argent Facility
- Argent Facility (Destroyed)
- Arion
- Arlene Sanders
- Armadosia
- Armageddon (ZPack episode)
- Armor
- Armor (Doom 2016)
- Armor Shard
- Armor bonus
- Armor percentage rollover
- Armored Baron
- Armored Response Coalition
- Armorer
- Armors
- Army of Darkness TC
- Arrival
- Artifact
- Asher Mahonin
- Aspect ratio
- Assassin
- Assault Rifle (movie)
- Assault rifle
- Assault rifle (Doom)
- Assault rifle (Strife)
- Atari
- Atari 2600
- Atari Jaguar
- Atlan
- Autoaim
- Automap
- Automap asteroids
- Automatic Turret
- Axe
- B.J. Blazkowicz
- B.P.R.D
- BAD MOOD
- BEX
- BFG-10000
- BFG9000
- BFG9000/Doom
- BFG9000/Doom: The Dark Ages
- BFG9000/Doom (2016)
- BFG9000/Doom 3
- BFG9000/Doom 64
- BFG9000/Doom Eternal
- BFG9000/Doom RPG
- BFG (Doom movie)
- BFG (disambiguation)
- BFG timeline
- BSP
- BSP (node builder)
- BZDoom
- Baalgar
- Bababooey
- Babel
- Back to Saturn X
- Back to Saturn X: Episode 1
- Back to Saturn X: Episode 2
- Backpack
- Bag of Holding
- Ballista
- Ballistatron
- Banishment Device
- Banshee
- Bar keep
- Baratus
- Baron of Hell
- Baron of Hell/Doom
- Baron of Hell/Doom (2016)
- Baron of Hell/Doom 64
- Baron of Hell/Doom Eternal
- Baron of Hell/Doom RPG
- Barrel
- Barrel explosions which do no damage
- Barrel suicide
- Basics of the WAD format
- Batman Doom
- Battlemode
- Bayonet
- Beggars
- Behavior
- Behemoth
- Beholder
- Beldin
- Belias
- Bella 2
- Belphegor
- Ben Morris
- Ben Wolfe
- Bennett Stone
- Bernd Kreimeier
- Bernie Lipsitz
- Berserk
- Berserk (Doom 2016)
- Berserk Hunter
- Berserker
- Best of Doom
- Bethesda Pinball
- Bethian
- Betrayer
- Beyond Reality
- Bill Koch (Bloodshedder)
- Bill Ritch
- Bill Tyson
- Billygoat
- Bio-Suit Zombie
- Bishop
- Björn Ostmann (Vader)
- Blackbird
- Blade Of Agony
- Blasphemer
- Blast damage
- Blast damage has unlimited vertical range
- Blazkowicz
- Blind spots in Doom reject tables
- Blockmap
- Blood
- Blood Keep
- Blood Maykr
- Blood Punch
- Blood Splatter
- Blood TC
- Bloodfall
- Bloodscourge
- Bloom
- Blue Chalice
- Blue Mana
- Blue Talisman
- Bob Larkin
- Boney
- Boom
- Boots of Speed
- Boris Iwanski
- Boris Pereira
- Boss
- Boss Brain (Doom II)
- Box of bullets
- Box of bullets (Strife)
- Box of rockets
- Box of shotgun shells
- BrDOOM
- Brad Carney (Carnevil)
- Bradley Jensen
- Bravo Marine
- Bravo Marine (Doom Resurrection)
- Bravo Team
- Brett Harrell (Mechadon)
- Brian Mora
- Brian Pelletier
- Brian Raffel
- Brier
- Brown chaos serpent
- Bruce A. Lewis
- Bruce Jackson
- Bruiser
- Brutal Doom
- Brutal Fate
- Brutal Hexen
- Buff Totem
- Bug
- Bull Demon
- Bullet
- Bullet clip
- Bullet puffs do not appear in outdoor areas
- Burst Rifle
- Burst Soldier
- Buzzer
- C. Rodgers
- C2Doom
- CDoom
- CDoom (disambiguation)
- CDoom (mobile)
- COLORMAP
- CROSS.WAD
- CTFDoom
- Caco-Spectre
- Cacodemon
- Cacodemon/Doom
- Cacodemon/Doom: The Dark Ages
- Cacodemon/Doom (2016)
- Cacodemon/Doom 3
- Cacodemon/Doom 64
- Cacodemon/Doom Eternal
- Cacodemon/Doom RPG
- Cacodemon (disambiguation)
- Cacowards
- Calamity blade
- Caldex Castle
- Camera
- Camera texture
- Canine
- Canon
- Captain
- Capture the Flag
- Carcass
- Carlos Guariglia
- Casey Alvis
- Catullus Steelworks
- Caverns - Area 1: Excavation Transfer
- Caverns - Area 2: Artifact Excavation
- Ceiling turret
- Celestial Locator