As a nameless space marine, players trek through over 24 levels (split up into three episodes), where they liberate space stations from demon infestation in both Phobos and Deimos, only to take on Hell. The game's engine (later known as id Tech 1) is known to pioneer new features to the genre, including non-perpendicular walls, complex rooms (known as "sectors") with varying height differences, multiplayer (both co-operatively and competitively, for up to four players at a time) and the concept of packaging the game's content (levels, sounds, and music) into singular data files (WAD files) for easier modification and distribution, leading to the birth of the modern mod-making community.
The lore of the game, set sometime into the future, involves the Union Aerospace Corporation (U.A.C.), a multi-planetary conglomerate that has been utilized by the Earth military to secretly experiment on alien teleportation technology discovered on the moons of Mars. As they try to establish a gateway between the two moons using this technology, the experiment goes awry and the demons of Hell use the portals to invade the two moons. As the last man standing guarding the Hangar of the U.A.C. space station on Phobos, the lone space marine must fight through the onslaught to keep them from attacking Earth.
While the original game was a shareware mail-order release, a special edition of the game (known as The Ultimate Doom) was later distributed in retail boxed format. Also released as a free upgrade for those who own the original game, The Ultimate Doom added a new epilogue episode (Thy Flesh Consumed) bridging the game with its sequel, Doom II: Hell on Earth. The original game also spawned multiple sequels and reboots, numerous console ports, a 2005 sci-fi action film, and a wide variety of unofficial source ports and enhancements (thanks to the decision to release the source code with minimal restriction).
In Doom, players progress through each level, blasting away enemies while solving puzzles (involving switches, keycards, and skull-shaped key devices), avoiding environmental hazards (such as crushing ceilings, radioactive acid, and burning lava), and collecting weapons, ammo, and other items (including first-aid kits, body armor, suits that protect from radiation, night-vision goggles, computer maps, and supernatural orbs that grant a special bonus to the player). Unlike id's previous first-person shooter, Spear of Destiny, Doom does not include a scoring or lives system. Players who die can retry the level at the cost of resetting their inventory and stats.
Episodes and Difficulties
The game's campaign is split up into three episodes (each with eight normal levels and one secret level):
- Knee-Deep in the Dead - The only episode playable in the shareware version, the first episode deals with the marine's journey through the base established on Phobos.
- The Shores of Hell - After defeating the two big bruisers guarding the teleportation gateway, the marine passes through into Deimos. As the invasion continues, the base becomes more distorted with hellish architecture. The second episode deals with the marine's liberation of demons from the Deimos base.
Inferno - Eventually, the marine fights a giant anomaly of flesh and metal (known as the Cyberdemon) in the "Tower of Babel", only to find out Deimos has been teleported to the infernal afterlife, and that the tower connects the moon to Hell itself! The third (and final) episode has the marine blindly wreaking havoc in Hell until he can find the mastermind behind the invasion.
Players who are starting a new game can start at the beginning of an episode (starting with no armor and a pistol with 50 bullets). Starting from the second episode, players can find two new cell energy weapons (the uncommon Plasma Gun and the rare BFG-9000) and two new common enemies (the Cacodemon and the Lost Soul). Players can pick between five difficulties (known as "skill levels"):
- I'm too young to die. - Fewer monsters and more items. Double ammo granted on weapon and ammo pickups. Players take half damage.
- Hey, not too rough. - Fewer monsters and more items.
- Hurt me plenty. - Normal difficulty.
- Ultra-Violence. - More monsters and fewer items.
- Nightmare! - Added in v1.2. Cheat codes are disabled. More monsters and fewer items. Double ammo granted on weapon and ammo pickups. Monsters react and move faster, and respawn shortly after death.
One of two starting weapons. The fist is simple and effective against weaker enemies but when a Berserk Pack power up is activated it boosts the attack power of the fist considerably allowing the Doom marine to tear through and even gib many enemies with ease.
From the manual: "Can be used to punch enemies. It will always be with you."
A powerful melee weapon capable of stunning some enemies.
From the manual: "Cuts down the baddies like standing timber, but you have to get close."
The second starting weapon. The pistol is one of two weapons to utilize bullets as its ammunition.
From the manual: "Your standard military-issue weapon. It will stay with you, so don't forget about it if things get tough."
The shotgun is a very effective weapon to use on most enemies the Doom marine will encounter. Its multi-pellet spread is very useful for crowds. The shotgun is the only weapon to use shells as its ammunition.
From the manual: "Deliver a heavy punch at close range and a generous pelting from a distance."
The chaingun, like the pistol, uses bullets as its source of ammunition. This rapid-firing machine gun can stun some enemies so it is most effective against a single enemy.
From the manual: "Direct heavy firepower into your opponent, making him do the chaingun cha-cha."
The Rocket Launcher is one of three weapons capable of gibbing enemies. Rockets deliver splash damage very well so they are ideal for dealing with crowds. This weapon is the only one in the game to use rockets as its ammunition.
From the manual: "Deliver an explosive rocket that can turn one bad dude inside-out."
The fastest firing weapon in the game, this weapon is very powerful and effective against whatever it is the Doom marine may encounter. The plasma rifle is one of two weapons to utilize cells as its ammunition.
From the manual: "Shoot multiple rounds of plasma energy - frying some demon butt!"
The BFG 9000 fires a huge plasma ball which moves slowly through the air. Upon impact, the target it hits receives a huge amount of damage and lots of splash damage as well.
From the manual: "The prize of the military arsenal. Great for clearing the room of an unwelcome guest. Shoot it and see for yourself."
Total in single player (ultra violence) : 311
From the manual: "Once a marine, always a marine-- except in this case. These guys may look like your old buddies, but now they're nothing more than pistol-toting bi-pedal maggots. Waste em!"
Total in single player (ultra violence) : 426
From the manual: "Ditto. Except these guys are meaner and tougher. These walking shotguns will provide you with a few extra holes if you're not careful."
Total in single player (ultra violence) : 719
From the manual: "You though an imp was a cute little dude in a red suit with a pitchfork. Think again. This Imp heaves balls of fire down your throat and takes several bullets to die. It's time to find a better weapon than a pistol if you're going to face more than one of these mutants."
Total in single player (ultra violence) : 389
From the manual: "Sorta like shaved gorillas, except with big heads and lots of teeth. They don't kill easy. Get too close and they'll rip your sorry head off."
Total in single player (ultra violence) : 114
From the manual: "Great. Just what you needed. An invisible (nearly) monster. Did you expect a walk in the park?"
Total in single player (ultra violence) : 242
From the manual: "Dumb. Tough. Flies. On Fire. 'Nuff said."
Total in single player (ultra violence) : 126
From the manual: "They float in the air, belch ball lightning, and have one horrendously big mouth. If you get too close to one of these monstrosities, You're Toast."
Total in single player (ultra violence) : 37
From the manual: "Tough as a dump truck and nearly as big, these goliaths are the worst thing on two legs since Tyrannosaurus Rex."
Total in single player (ultra violence) : 2
From the manual: "Half unfeeling machine, half raging horned devil. This walking nightmare has a rocket launcher for an arm and will definitely reach out and touch you. Make sure you're loaded for bear before you get to this guy."
Spiderdemon (Spider Mastermind)Health: 3000
Total in single player (ultra violence) : 1
From the manual: "Maybe cybernetics wasn't such a great idea after all. Look what the demons have done with it. It somehow seems unfair that you're not the only guy in Hell with a chaingun. Nope, she has a Super-Chaingun don't you just love it?"
Episodes and Maps
Knee-Deep in the Dead (E1)
|Level Name||Map Slot||Designer||Par Time|
|Nuclear Plant||E1M2||John Romero||1:15|
|Toxin Refinery||E1M3||John Romero||2:00|
|Command Control||E1M4||Tom Hall, John Romero||1:30|
|Phobos Lab||E1M5||John Romero||2:45|
|Central Processing||E1M6||John Romero||3:00|
|Computer Station||E1M7||John Romero||3:00|
|Phobos Anomaly||E1M8||Sandy Petersen, Tom Hall||N/A|
|Military Base (secret level)||E1M9||John Romero||2:45|
|Sewers (Xbox only secret map)||E1M10||David Calvin||0:00|
The Shores of Hell (E2)
|Level Name||Map Slot||Designer||Par time|
|Deimos Anomaly||E2M1||Sandy Petersen, Tom Hall||1:30|
|Containment Area||E2M2||Tom Hall, Sandy Petersen||1:30|
|Refinery||E2M3||Tom Hall, Sandy Petersen||1:30|
|Deimos Lab||E2M4||Tom Hall, Sandy Petersen||2:00|
|Command Center||E2M5||Sandy Petersen||1:30|
|Hall of the Damned||E2M6||Sandy Petersen||6:00|
|Spawning Vats||E2M7||Tom Hall, Sandy Petersen||4:00|
|Tower of Babel||E2M8||Sandy Petersen||N/A|
|Fortress of Mystery||E2M9||Sandy Petersen||2:50|
|Level Name||Map Slot||Designer||Par Time|
|Hell Keep||E3M1||Sandy Petersen||1:30|
|Slough of Despair||E3M2||Sandy Petersen||0:45|
|Pandemonium||E3M3||Tom Hall, Sandy Petersen||1:30|
|House of Pain||E3M4||Sandy Petersen||2:30|
|Unholy Cathedral||E3M5||Sandy Petersen||1:30|
|Mt. Erebus||E3M6||Sandy Petersen||1:30|
|Limbo||E3M7||Tom Hall, Sandy Petersen||2:45|
Like id's previous first-person shooter, Wolfenstein 3D, Doom was ported to a variety of consoles throughout the 90's (both by id themselves and third-party developers). Each port of the game have their own unique optimizations, limitations, and differences.
Developed alongside the Jaguar version below, the Sega 32X version of Doom was developed by Sega (with direct involvement from John Carmack) and was released by Sega on November 21, 1994 as a launch title for that system (alongside Star Wars Arcade). It is the first officially released port of the game.
Although the game engine is smooth and advanced for the hardware used, it came with an abundance of limitations. Like the Jaguar-based version, much of the levels' textures and structures were heavily optimized, and the game only a subset of levels from the original game (17 levels, none of which are from the third episode) played sequentially. The Cyberdemon, Spider Mastermind, and Spectre enemies are absent, some items were removed, the BFG-9000 weapon is only obtainable through a cheat code, and all enemies have only front-facing sprites (which also eliminates the possibility of monster infighting). Unlike other versions of the game (except the 3DO version below), the game's screen must be bordered. The music quality has also been degraded due to poor use of the Genesis's sound chip. There are no multiplayer modes included.
One interesting thing to note is that while the game does not feature game saving, it allows players to start from any level. Levels 16 (the final level) and 17 (the secret level) can only be accessed if the player starts at Level 1 and does not use any cheat codes. Attempting to get to the secret level otherwise would skip to the next level, while attempting to get to the final level otherwise would roll through the credits and show a fake DOS prompt (which stays until the console is reset). Beating the final level gives an extra congratulatory message and "staff roll" of the game's enemies (similar to Doom II: Hell on Earth).
Developed alongside the Sega 32X version, the Atari Jaguar version was developed in-house and released on November 28, 1994.
Like the Sega 32X version, the game engine is smooth and advanced for the hardware used and much of the levels' textures and structures were heavily optimized. The game uses a larger subset of levels from the original game (22 levels, one of which is a secret level) and two new replacement levels, all of which are played sequentially. Unlike other ports, there is no music during gameplay (It only plays during the title and intermission screens, where the intermission music is replaced by that level's theme). The Cyberdemon, Spider Mastermind, and Spectre enemies are absent, some items were removed, and enemies no longer respawn on the hardest difficulty.
Although there is no manual game saving option, the game automatically tracks the last level completed and allows players to start from any completed level in the main menu. The game also features two-player link cable multiplayer (using the JagLink networking device).
One interesting thing to note is that the large amount of buttons on the controller's keypad allows players to switch to any weapon without the need to scroll through weapons. An overlay was included that slipped onto the controller to help accommodate this.
Unlike most ports released, the source code for this version was released publicly and served as the basis for most of the future ports (including the 3DO, PS1, and GBA versions).
Super Nintendo Entertainment System
The Super Nintendo Entertainment System version of Doom was developed in-secret by Sculptured and published by Williams (after id's approval) on September 1, 1995. It was later published in Japan by Imagineer.
The only 16-bit port developed, the SNES version was built on a custom game engine and is one of the few titles to use the Super FX 2 co-processor to help render the game. Due to the hardware limitations of the console, texture and sprite quality were heavily degraded (floors and ceilings had no textures mapped onto them and all enemies only had front-facing sprites). The Spectre enemy is absent, some items were removed, enemies no longer respawn on the hardest difficulty, monster infighting was removed, and particle effects (such as blood and bullet impacts) were removed. Enemies must visually notice the player to become active. The shotgun also fires only one projectile instead of multiple projectiles (similar to shotgun slugs).
While the game does not include all levels from the original version (22 total), it is the only early port to retain the episodic format of the original. It does not support game saving at any capacity. One interesting thing to note is that in non-Japanese revisions of the port, the two easiest difficulties were only playable on the first episode and players cannot start on the third episode on the normal difficulty.
Unique to this version of the game is the Mode 7 automap, which rotates the map around the player instead of keeping the map in a fixed rotation. This port also supports mouse capability with the SNES Mouse and, exclusive to the home versions, two-player online multiplayer support (Deathmatch mode only) via the XBAND modem.
Based on the Jaguar version, the Sony PlayStation version of Doom was developed and published by Williams on November 16, 1995.
Along with all of the Jaguar version levels, this version adds one level from the original game, five levels from the Ultimate Doom expansion, 23 levels from Doom II: Hell on Earth, and six new levels (for a total of 59 levels). The levels are split into two "episodes" (one for Ultimate Doom and one for Doom II). While the hardest difficulty was removed, the hard difficulty now adds monsters from Doom II into the original levels. In addition, a new harder type of enemy, the Nightmare Spectre, was added.
The game's engine is a significant improvement over the Jaguar version, adding colorized lighting, translucent walls/sprites, and animated skies. The audio was also replaced completely, including new sound effects and a darker, more atmospheric ambient soundtrack. The game also supports two-player link cable multiplayer (using the PlayStation Link Cable). While there is no game saving, this version introduces a new password system.
This version would later receive a sequel, titled Final Doom, comprised of levels from both Final Doom expansions and the Master Levels for Doom II expansion. While the gameplay and audio remains the same, support was added for mouse capability with the PlayStation Mouse. The sound effects and voice-overs were also re-used for Doom 64 (along with a similar ambient soundtrack from the same musician).
3DO Interactive Multiplayer
Retaining most of the limitations of the Jaguar version (adding the Spectre enemy back in), the 3DO version runs at a low framerate with a heavily-bordered screen. The screen size can be increased with a cheat code, but it severely limits the framerate (at times making it near-unplayable). There is no multiplayer support.
Unique to this version is a CD-quality arranged soundtrack, performed by an unknown band hired by ADI.
The source code for this port was released by its sole developer in late 2014.
Known as WinDoom or Doom95, developed for Windows, unveiled in 1995 and released in 1996, this port capitalized on the popularity of Doom and was used by Microsoft to showcase their new DirectX technology. It supports screen resolutions up to 640x480 and features a GUI launcher allowing easy selection of episode, map, difficulty, custom wads, and multiplayer settings.
Much of the additions from the PlayStation port's engine (such as colored lighting, translucency, and animated skies) were not included. It also runs at a low framerate (comparable to the 3DO version). Only the European and Japanese releases includes two-player link cable multiplayer (despite the back of the North American box stating that it's supported).
Game Boy Advance
Retaining most of the limitations of the Jaguar version, the GBA is known for its game censorship (to reduce its content rating down to 13+) changing all the red blood of enemies to green, having all enemy corpses disappear after a few seconds, and removing all gib effects.
All of the Jaguar version's levels are retained, though the game includes an episode selection screen that allows the player to start in a later set of levels. This version also adds between-level game saving with up to four save slots. The game also includes link multiplayer for up to four players (each with their own copy of the game and Link Cables) and eight exclusive maps for deathmatch play.
The Xbox port of Doom was developed by Vicarious Visions and was included (alongside Doom II) with both the collector's edition of the Xbox release of Doom 3 (on April 23, 2005) and the Xbox release of Doom 3: Resurrection of Evil (on October 5, 2005), both published by Activision. It is the first official source port based on the official release of the source code.
Along with some glitches, the Xbox version is known for its inclusion of split-screen multiplayer (with up to four players), controller-based cheat codes, and a hidden exclusive level ("Sewers", made in 1994 from the lead programmer for the Doom 3 port).
Likely based on the Xbox version above (without the glitches or extra content), the Xbox 360 version of Doom was developed by Nerve and published by Activision digitally for Xbox Live Arcade on September 27, 2006. It is the first official source port that is digitally distributed and the first to be nearly identical to the original game.
Some additions to this version include high definition rendering, surround sound support, achievements, online leaderboards, split-screen multiplayer, and online multiplayer (via Xbox Live) for up to four players.
Doom II also received an Xbox 360 release (itself featuring a new nine-level episode). Both versions were pulled from the marketplace in 2010 and were re-published by Bethesda in early 2012. Both versions are also backwards-compatible with the Xbox One and were offered as pre-order bonuses for the Xbox One version of the Doom re-boot.
Released in 2012 in a collection called "Doom Classic Complete" which features The Ultimate Doom, Doom 2, Master Levels for Doom 2. This collection also includes the previously exclusive No Rest for the Living bonus episode from the Xbox 360 release of Doom 2. This port features a stripped down version of idtech 5 for networking and other PSN specific code written during the development of RAGE.
iPhone / iPod Touch
An official iOS port of Doom, titled Classic Doom, was released by id Software in 2009. The port is based on the source port PrBoom which allows for OpenGL rendering.
The Linux port of Doom was created by Dave Taylor of id Software and released in 1994. The source code of this port was made available to the public in 1997 and is the basis for all subsequent source ports.
Unofficial Source Ports
On December 23 1997, Doom's source code was made available to the public. Thanks to the game's popularity, the active mod-making community, and the support of its fans, this release spawned many new versions of the game engine (known as "source ports") for modern computer platforms that are still active to this day.
While some, like Chocolate Doom, maintain the original game's compatibility and look-and-feel, most derived ports (such as Boom, ZDoom, and Zandronum) update the game's engine to add a variety of new features, including optimized online multiplayer, high resolution rendering, removal of the original engine's limitations, additional control options (including jumping, crouching, the ability to look up and down, and swimming), support for numerous scripting languages (including those that allow custom enemies and weapons), support for other id Tech 1 games (such as Heretic, Hexen, and Strife), and new special effects (such as slopes, colored lighting, and 3D floors).
In addition to desktop computer platforms, source ports have been created for a variety of homebrew-enabled consoles and handheld devices, including the Sega Dreamcast, Xbox, Nintendo DS, PlayStation Portable, PlayStation Vita, Nintendo Wii, and Nintendo 64, as well as all iOS and Android devices. Ports have also been made to browsers (most notably in Adobe Flash), Doom 3 (in a playable terminal), and embedded systems (such as ATM machines).
All source ports require a valid Doom data file (or IWAD) to run, which can only be found in PC versions of the game. A list of all standard source ports can be found here. A blog featuring esoteric things that can run Doom can be found here.
Minimum System Requirements
- 386sx IBM compatible computer
- MS-DOS v3.3 or higher
- VGA (320x200x256) graphics
- 4mb RAM
- Hard Drive - 4.8 MB (Shareware), 12 MB (Mail-order)
Original Release Versions
- Includes one of the three episodes
- Includes network and modem support
- All shareware features
- Includes all three episodes (three episodes each with eight levels and a secret level)
- Includes Plasma rifle
- Includes BFG 9000
- v0.2 - February 4, 1993 (alpha version)
- v0.4 - April 2, 1993 (alpha version)
- v0.5 - May 22, 1993 (alpha version)
- v1.0 - December 10, 1993 (uses v0.99 engine)
- v1.1 - December 16, 1993
- v1.2 - February 17, 1994 (introduced modem support and Nightmare mode)
- v1.3 - undocumented / never released
- v1.4 - June 1994 (Internet Beta version)
- v1.5 - July 8, 1994 (Internet Beta version)
- v1.6 - August 1994 (Internet Beta version)
- v1.666 - September 1994
- v1.7 - October 11, 1994
- v1.7a - November 8, 1994
- v1.8 - January 23, 1995
- v1.9 - February 1, 1995 (the final version)
Ultimate Doom, released April 1995, used a slightly modified version of the engine however the version number was not updated.
On December 23 1997 the Doom source code was released, this code has the version number 1.10
Referencing this new version, source port authors (e.g., ZDoom) often began their versions with 1.11
On October 4, 1993 an early beta version of the game was made available to journalists. While this version of the game is similar to the final version (unlike the earlier alpha versions) there are still several key differences, most notably the BFG9000 which fired 40 quick bursts of plasma gun ammo. This was changed due to the large number of sprites on screen causing the PC to slowdown. Also, this version has a scoring system. The player could gain score by killing enemies and collecting score giving items such as the Demonic Dagger. The scoring system and scoring items did not make it into the final version of the game.