Doom is a 1993 first-person shooter game created and released by id Software for MS-DOS. It is the first game in the Doom series. Players take the role of a space marine, later called Doomguy, who fights through large groups of undead humans and demons. The game starts on the moons of Mars and ends in hell, with players moving through each level to find an exit or defeat a boss. Doom was one of the first games to use 3D graphics, though enemies and objects were made from 2D images, a method sometimes called 2.5D graphics.
Doom was the third major game made by id Software, following Commander Keen (1990–1991) and Wolfenstein 3D (1992). In May 1992, id began working on a new game focused on fighting demons, using a 3D engine developed by John Carmack, the lead programmer. Tom Hall first wrote a science fiction story for the game, but most of it was removed. The final game had an action-focused design by John Romero and Sandy Petersen. Id released Doom as three episodes using the shareware model, giving the first episode for free. A retail version with an extra episode was released in 1995 by GT Interactive as The Ultimate Doom.
Doom was very successful and is considered one of the best and most influential video games ever made. It sold about 3.5 million copies by 1999, and up to 20 million people are estimated to have played it within two years of its release. It is called the "father" of first-person shooters and is seen as a key game in the genre. Historians say Doom changed how people viewed video games and helped create online gaming and communities. It inspired many similar games, led to a strong modding community, and started the practice of speedrunning. The game’s graphic violence caused controversy. Doom has been released on many platforms, both officially and unofficially, and has been followed by several games in the series, including Doom II (1994), Doom 64 (1997), Doom 3 (2004), Doom (2016), Doom Eternal (2020), and Doom: The Dark Ages (2025). It also inspired films such as Doom (2005) and Doom: Annihilation (2019).
Gameplay
Doom is a first-person shooter game that uses 3D graphics. Although the environment is shown in a 3D perspective, movement happens in a 2D plane, a technique sometimes called 2.5D graphics. Enemies and objects are 2D images, known as sprites, displayed at fixed angles, a method called billboarding. In the single-player campaign, the player controls an unnamed space marine, later called "Doomguy," who travels through military bases on Mars' moons and in hell. To complete a level, the player must move through maze-like areas to reach a marked exit room. Levels are divided into episodes, with the final level of each focusing on a boss fight.
As the player moves through levels, they must fight enemies such as demons and undead humans. Enemies often appear in large groups. Five difficulty levels change how many enemies are present and how much damage they deal. On the hardest difficulty, enemies move and attack faster. Enemies act in simple ways: they move toward the player if they see or hear them and attack by biting, clawing, or using magic abilities like fireballs.
The player must manage supplies like bullets, health, and armor while navigating levels. Weapons and ammunition can be found throughout levels or collected from defeated enemies, including a pistol, shotgun, chainsaw, plasma rifle, and the BFG 9000. The player also encounters hazards such as toxic waste pits, ceilings that drop and crush objects, and locked doors requiring a keycard or a switch. Power-ups include health or armor, a mapping computer, partial invisibility, a radiation suit to protect against toxic waste, invincibility, or a powerful melee mode. Cheat codes let players use all weapons, walk through walls, or be invincible.
Two multiplayer modes are available over a network: cooperative mode, where 2-4 players work together to finish the campaign, and deathmatch mode, where 2-4 players compete to kill each other as much as possible. Multiplayer was originally only playable on local networks, but an online mode for four players was added a year after release through the DWANGO service.
Plot
The game Doom is divided into three episodes, each with eight main levels: "Knee-Deep in the Dead," "The Shores of Hell," and "Inferno." A fourth episode, "Thy Flesh Consumed," was added later in an expanded version called The Ultimate Doom, which was released two years after the original Doom. The story includes few plot details, with most of the narrative explained through the instruction manual and text descriptions between episodes.
In the future, an unnamed marine is sent to a boring job on Mars after arguing with a leader who ordered his unit to attack civilians. The Union Aerospace Corporation, which manages radioactive waste facilities on Mars, allows the military to conduct secret teleportation experiments that become dangerous. A base on Phobos urgently asks for military help, while Deimos vanishes completely. The marine joins a combat force to protect Phobos. He secures the perimeter as ordered, but the entire response team is destroyed. With no way to leave the moon and only a pistol for protection, he enters the base to seek revenge.
In "Knee-Deep in the Dead," the marine fights demons and humans controlled by demons in military and waste facilities on Phobos. The episode ends with the marine defeating two powerful Barons of Hell guarding a teleporter to the Deimos base. After the battle, the marine enters the teleporter but is knocked unconscious by enemies and wakes up with only a pistol. In "The Shores of Hell," the marine battles through corrupted research facilities on Deimos, eventually defeating a large cyberdemon. From a high place, he sees the moon floating above hell and uses a rope to descend to the surface. In "Inferno," the marine fights through hell itself and destroys a cybernetic spider-demon responsible for invading the moons. When a portal to Earth opens, the marine enters and finds Earth has been attacked. "Thy Flesh Consumed" shows the marine attacking Earth invaders, setting up the story for Doom II.
Development
In May 1992, Id Software released Wolfenstein 3D, a video game that became known as the "grandfather of 3D shooters." It helped popularize the genre and set a standard for fast action and advanced technology. After releasing Wolfenstein 3D: Spear of Destiny in September 1992, the team at Id Software began planning their next project. They were tired of working on Wolfenstein and wanted to create a new 3D game using a new engine being developed by John Carmack, one of the company’s co-founders and lead programmers.
Tom Hall, another co-founder and lead designer, suggested making a new game in the Commander Keen series, but the team decided that the side-scrolling gameplay of Commander Keen did not match the fast-paced 3D technology they were developing. John Romero, another co-founder and lead artist Adrian Carmack (no relation to John Carmack), wanted to create a game with a darker style than Commander Keen.
John Carmack proposed a game about using technology to fight demons, inspired by a Dungeons & Dragons campaign the team played. This idea also influenced later games like Quake (1996) and Daikatana (2000). The team wanted to combine the styles of the movies Evil Dead II and Aliens. The game’s working title was Green and Pissed, but Carmack renamed it Doom after a line from the 1986 film The Color of Money: “What you got in there?” / “In here? Doom.”
In November 1992, the team agreed to develop Doom. The initial team included five people: programmers John Carmack and John Romero, artists Adrian Carmack and Kevin Cloud, and designer Tom Hall. They moved to a dark office building they called “Suite 666” and were inspired by sounds from a nearby dental office. They also decided to stop working with their previous publisher, Apogee Software, and self-publish Doom to make more money.
In November 1992, Tom Hall created a design document he called the “Doom Bible,” which described the game’s plot, backstory, and goals. His plan was a science fiction horror story where scientists on the Moon open a portal to an alien invasion. John Carmack disliked the story and believed games did not need detailed plots. Instead, he focused on technological innovation and wanted to create a continuous, fast-paced world. Hall revised the design document to match Carmack’s ideas, but the team later realized that Carmack’s vision was too advanced for the hardware available at the time, forcing Hall to revise the document again.
In early 1993, Id Software released a press statement about Doom, describing a story where players fight demons while “knee-deep in the dead.” The press release highlighted new features in Carmack’s 3D engine, such as multiplayer, which had not yet been designed. Early versions of the game followed the Doom Bible, including Hall’s introductory scene. However, the team later removed elements like arcade-style scoring, which clashed with Doom’s tone. They also tested and removed other systems, such as lives, inventory, and a complex user interface.
Eventually, the team rejected the Doom Bible as a whole. John Romero wanted a game even “more brutal and fast” than Wolfenstein, which did not include the character-driven story Hall had created. The team believed the story made the game too realistic and not fun enough. Most of the design was removed, but some ideas remained. By early 1993, Hall created levels that became part of an internal demo, but Carmack and Romero disliked the military-style architecture of Hall’s designs. Romero created his own, more abstract levels, which the team preferred.
Hall became frustrated with the team’s rejection of his ideas and the lack of progress on gameplay improvements, such as flying enemies. He spent less time at work, and the other developers believed he was not aligned with the team’s vision. In July 1993, Hall was fired and joined Apogee Software. He was replaced by Sandy Petersen in September 1993, ten weeks before the game’s release. Petersen later said that Carmack and Romero wanted to hire more artists, but Adrian Carmack and Kevin Cloud argued that a designer was needed to create a cohesive gameplay experience. The team also added a third programmer, Dave Taylor.
Petersen and Romero designed the rest of Doom’s levels. The team believed Petersen’s designs were more technically varied, while Romero’s were more visually interesting. In late 1993, John Carmack added multiplayer to the game. After coding the multiplayer feature, the team played four-player games, which Romero called “deathmatch,” and Cloud named the act of killing other players “fragging.” Romero said the deathmatch mode was inspired by fighting games like Street Fighter II, Fatal Fury, and Art of Fighting.
Doom was written mostly in the C programming language, with some parts in assembly language. The developers used NeXT computers running the NeXTSTEP operating system. Level and graphical data was stored in WAD files, short for “Where’s All the Data?” This system allowed changes to the game’s design without altering the engine code. Carmack created this system so fans could easily modify the game, inspired by the fan modifications of Wolfenstein 3D.
Unlike Wolfenstein, which had flat, right-angled levels, the Doom engine allowed walls and floors to be at any angle or height, but it did not support vertical stacking of areas. The lighting system adjusted the color palette of surfaces directly, rather than using complex calculations like ray tracing. It estimated the “light level” of a small area based on its brightness and changed the surface textures to look darker. This same system made distant surfaces appear darker than close ones.
John Romero used Carmack’s lighting engine to create effects like strobe lights. He also programmed features such as switches, movable stairs, and platforms. When Romero’s complex level designs caused problems with the engine, Carmack used binary space partitioning to quickly select the visible parts of a level. Taylor added cheat codes to help with development, and these codes remained in the final game.
Adrian Carmack was the lead artist on the project.
Release
Id Software planned to release the game Doom for computers that used the DOS operating system. They created a system to distribute the game before its release. Jay Wilbur, who was hired as the CEO and the only member of the business team, was responsible for planning how to market and distribute Doom. Id Software would earn more money by selling copies directly to customers—up to 85% of the planned $40 price—so Wilbur focused on using the shareware market. He believed that mainstream media would not be interested in the game and only bought one ad in a gaming magazine. Instead, he allowed software retailers to sell the first episode of Doom at any price, hoping this would encourage customers to buy the full game directly from Id. In 2004, John Carmack estimated that the total cost to develop Doom was less than $1 million.
The team originally planned to release Doom in the third quarter of 1993 but needed more time. By December 1993, the team worked nonstop, with some employees sleeping at the office. Taylor said the intense work made him feel so excited that he sometimes passed out. Id gave only one press preview to Computer Gaming World in June, which received positive feedback. They also shared updates about the game’s development with the public through the early internet. As anticipation grew, Id received many calls from people interested in the game or upset about the delayed release. At midnight on December 10, 1993, after working 30 hours straight, the team uploaded the first episode of Doom to the internet. They could not connect to the FTP server at the University of Wisconsin–Madison because too many users were already online. The network administrator had to increase the number of connections and then remove all users to make space. When the upload finished 30 minutes later, 10,000 people tried to download the game at once, which crashed the university’s network.
Soon after Doom was released, university networks began blocking Doom multiplayer games because too many players overwhelmed their systems. The next morning, John Carmack quickly released a patch to address complaints about network congestion. Administrators still had to create rules to prevent their networks from crashing due to the high demand.
In 1995, Id created an expanded version of Doom with a fourth episode of levels, which was published by GT Interactive as The Ultimate Doom. Doom was also ported to many other platforms, not directly by Id Software. The first unofficial port to Linux was made by Id programmer Dave Taylor in 1994. Microsoft tried to hire Id to port Doom to Windows in 1995 to promote Windows as a gaming platform, and Microsoft CEO Bill Gates briefly considered buying the company. When Id refused, Microsoft created its own licensed version of the game, led by Gabe Newell. One promotional video for Windows 95 showed Gates digitally added into the game.
Official ports of Doom were released for the 32X and Atari Jaguar in 1994, Super NES and PlayStation in 1995, 3DO in 1996, Sega Saturn in 1997, Acorn Risc PC in 1998, Game Boy Advance in 2001, Xbox 360 in 2006, iOS in 2009, and Nintendo Switch, Xbox One, PlayStation 4, and Android in 2019. The last platforms (excluding Android) received an expanded version of Doom alongside Doom II in 2024, along with ports for the PlayStation 5 and Xbox Series X/S. The 2016 "IDKFA" arranged soundtrack by Andrew Hulshult was also included. Some of these versions became bestsellers even many years after the initial release. Not all ports had the same content. For example, the 32X version, created by John Carmack, included only two-thirds of the game’s levels to meet the console’s launch date, while the PlayStation version included The Ultimate Doom and Doom II.
The source code for Doom was released under a non-commercial license in 1997 and later made freely available under the GNU General Public License in 1999. Because the source code was shared, Doom was unofficially ported to many other platforms. These ports included unusual devices like smart thermostats, pianos, and even Doom itself. This led to the creation of a popular meme: "Can it run Doom?" and "It runs Doom."
Reception
In December 1993, the game Doom became a big success very quickly. It made money on the first day it was released. The company estimated that only 1% of people who downloaded the free version bought the full game, but this was enough to earn $100,000 each day. Doom sold as many copies in one day as another game, Wolfenstein, sold in one month. By May 1994, the company said the game had sold over 65,000 copies, and the free version had been shared more than 1 million times. In 1995, the company estimated that 140,000 copies were sold in the first year. In 2002, another person said about 200,000 copies were sold in the first year.
By late 1995, Doom was estimated to be installed on more computers worldwide than Microsoft’s new operating system, Windows 95. By June 1996, the game had been downloaded 20 million times. By April 1998, the free version of Doom had sold 1.36 million copies in the United States and earned $8.74 million. This made it the fourth-best-selling computer game in the country since 1993. By September 1999, the Ultimate Doom version had sold over 780,000 copies, and all versions combined sold 3.5 million copies by the end of 1999. By 2002, about six million people had played the free version. Other sources estimated that 10 to 20 million people played Doom within 24 months of its release.
Doom received many positive reviews. In April 1994, PC Gamer UK named it the third-best computer game of all time, saying it helped make the PC a popular choice for arcade-style games. PC Gamer US named it the best computer game of all time that same year. It won the Best Action Adventure award at Cybermania ’94. GamesRadar UK named Doom Game of the Year in 1993, and Computer Gaming World and PC Gamer UK did the same the following year.
Reviewers said the single-player mode was very good. One magazine called it “a skull-banging, palm-sweating, blood-pounding game,” while another said it was “a technically superb and thrilling 3D adventure.” A reviewer from White Wolf said the game was addictive, causing them to miss sleep and appointments. PC Zone called it the best arcade game ever, and other magazines praised the variety of monsters and weapons. Computer Gaming World said it was “a virtuoso performance.” Some reviewers noted the gameplay was simple, calling it repetitive or lacking depth. Others praised the graphics, levels, and music, but one review joked that “if only you could talk to these creatures, then perhaps you could try and make friends with them,” which became a popular joke.
The multiplayer mode was also praised. Computer Gaming World called it “the most intense gaming experience available,” and Dragon called it “the biggest adrenaline rush available on computers.” PC Zone named it the best multiplayer game and the best arcade game.
The 3D graphics and art style were highly praised. Computer Gaming World called the graphics remarkable, and Edge said the game “made serious advances in what people will expect of 3D graphics in the future.” Many magazines said the level design, lighting, and sound effects created a “claustrophobic” and “nightmarish experience.” Computer Gaming World and The Mercury News also praised the music.
The Ultimate Doom received mixed reviews in 1995. PC Zone gave it a score of 90/100 for new players but 20/100 for those who had already played the original game, saying it was just a collection of new levels. Joystick said it had limited new content and recommended it only for major fans. Fusion and GameSpot praised the difficulty of the new levels, with GameSpot saying it was good for introducing the game to new players.
The first versions of Doom for other systems received reviews similar to the original PC version. The Jaguar version was praised by several magazines, and the 32X version was also highly rated, though its graphics were worse and the game shorter. The 1995 ports had mixed reviews. The PlayStation version was praised for including Doom II and extra levels, while the Super NES version had weaker graphics and unresponsive controls. Later versions in the 1990s received worse reviews. The 3DO version was criticized for worse graphics and smaller screen size, and the Sega Saturn version was also poorly reviewed for its low-quality graphics.
Legacy
Doom is often called the most important first-person shooter game and is known as the "father" of the genre. Though not the first game in this category, it had the greatest impact on the development of video games. In 2013, Dan Pinchbeck wrote in Doom: Scarydarkfast that the design choices in Doom directly influenced first-person and third-person shooter games two decades later, even after other games were released in between.
Doom, along with Wolfenstein 3D to a lesser extent, is described as a turning point in how video games were viewed in popular culture. Doom and first-person shooters became the most common way video games were represented in media. Historians like Tristan Donovan in Replay: The History of Video Games (2010) said Doom caused a major change in the video game industry, leading to the rise of 3D games, first-person shooters, shared technology between developers, and support for game modifications. It also helped create online multiplayer games and player-created content, and popularized the idea of selling games online. In Dungeons & Dreamers: A Story of How Computer Games Created a Global Community (2014), Brad King and John Borland said Doom was one of the first widely shared examples of an "online collective virtual reality" and helped build the modern world of networked games and players. In 2004, PC Gamer named Doom the most influential game of all time, and in 2023, it was called one of the best-documented game developments in history.
Since its release, Doom has been used in scholarly research, including studies on machine learning, video game design, and the effects of video games on aggression, memory, and attention. In 2026, Australian researchers trained 200,000 human brain cells as an organic computer to play Doom. In 2007, Doom was listed among the ten "game canon" video games chosen for preservation by the Library of Congress. In 2015, The Strong National Museum of Play added Doom to its World Video Game Hall of Fame.
Doom has remained highly ranked in lists of the best video games ever made. In 1995, Next Generation called it "the most talked about PC game ever." The PC version was ranked third best by Flux in 1995 and fifth best and third most innovative by Computer Gaming World in 1996. In 2000, GameSpot ranked it as the second-best game ever. In 2001, it was named the top game of all time in a poll of over 100 developers and journalists by GameSpy, and sixth best by Game Informer. GameTrailers called it the most "breakthrough PC game" in 2009, and Game Informer again ranked it sixth best that same year. Doom has also been included in lists of the best games of all time by GamesMaster, Hyper, The Independent, Entertainment Weekly, GamesTM, Jeuxvideo.com, Gamereactor, Time, Polygon, and The Times, among others, as recently as 2023.
The success of Doom led to many new first-person shooter games. In 1998, PC Gamer said Doom was "probably the most imitated game of all time." These games were often called "Doom clones," and the term "first-person shooter" became the name for the genre after a few years. At the time, Doom was described as a "first-person perspective adventure" and "atmospheric 3-D action game."
Doom clones ranged from games that closely copied Doom to more creative versions of the genre. Id Software, the company that made Doom, licensed the Doom engine to other companies, leading to games like Heretic (1994), Hexen: Beyond Heretic (1995), and Strife: Quest for the Sigil (1996). A Doom-based game called Chex Quest was released in 1996 by Ralston Foods as a promotion to sell cereal. Other games, like Star Wars: Dark Forces (1995) by LucasArts, were inspired by Doom, though some were rumored to be built by reverse-engineering the game's code. Games like PowerSlave (1996) and Duke Nukem 3D (1996) used the 1995 Build engine, a 2.5D engine inspired by Doom.
After completing Doom, id Software worked on a sequel called Doom II, which was released on October 10, 1994, ten months after the first game. GT Interactive had approached id before Doom's release with plans to sell Doom and Doom II in stores. Id chose to make the sequel as a set of episodes rather than a new game, allowing John Carmack and other programmers to start work on Quake. Doom II was the highest-selling software product in the United States in 1994 and sold over 1.2 million copies within a year.
Following Doom II, id released Master Levels for Doom II (1995), which included 21 commissioned levels and over 3,000 user-created levels for Doom and Doom II. Two sets of Doom II levels by amateur map-making teams were released together as the standalone game Final Doom (1996). Doom and Doom II were included in the id Anthology compilation (1996). The Doom franchise continued after the 1990s with games like Doom 3 (2004), Doom (2016), and Doom Eternal (2020), along with other spin-offs, novels, a comic book, board games, and films: Doom (2005) and Doom: Annihilation (2019).
Doom was known for its graphic violence and satanic imagery, which caused controversy. The 32X version of Doom was one of the first games to receive a Mature 17+ rating from the Entertainment Software Rating Board because of its violent content. In Germany, Doom was classified as "harmful to minors" by the Federal Department for Media Harmful to Young Persons shortly after