Doom is a 1993 first-person shooter game made and sold by id Software for computers using MS-DOS. It is the first game in the Doom series. The player controls a space marine, who is later called Doomguy, fighting against large groups of undead humans and demons. The game starts on the moons of Mars and ends in hell. Players move through each level to find an exit or beat the final boss. It was one of the first games to use 3D graphics. Enemies and objects are 2D images, a method known as 2.5D graphics.
Doom was the third major game released by id Software, following Commander Keen (1990–1991) and Wolfenstein 3D (1992). In May 1992, id Software began creating a darker game centered on fighting demons using new 3D technology from John Carmack, the lead programmer. Designer Tom Hall first wrote a science fiction story, but most of it was removed. The final game focused more on action, designed by John Romero and Sandy Petersen. Id Software released Doom in three parts using the shareware model, giving the first part for free to promote the full game. A retail version with an extra part was released in 1995 by GT Interactive as The Ultimate Doom.
Doom was very successful, both in reviews and sales, 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 thought to have played it within two years of its release. It is called the "father" of first-person shooters and is seen as one of the most important games in that genre. Video game historians say it changed the direction and how people see video games, and helped start online gaming and communities. It inspired many similar games and clones, along with a strong modding community and the start of speedrunning as a hobby. Its high level of graphic violence caused controversy among various groups.
Doom has been adapted for many platforms, both officially and unofficially. It was 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). There are also films based on the game: Doom (2005) and Doom: Annihilation (2019).
Gameplay
Doom is a first-person shooter game that uses 3D graphics. Although the game world appears in 3D, movement is limited to a flat, two-dimensional (2D) plane, a method sometimes called 2.5D graphics. Enemies and objects are 2D images that always face the player, a technique known as billboarding. In the single-player campaign, the player controls an unnamed space marine, later called "Doomguy," as they explore military bases on Mars' moons and in hell. To complete a level, the player must navigate maze-like areas to reach an exit room. Levels are grouped into named episodes, with each ending in a battle against a boss.
During gameplay, the player fights enemies such as demons and possessed humans. Enemies often appear in large groups. Five difficulty settings change the number of enemies and the damage they cause, with enemies moving and attacking faster on the hardest setting. Enemies follow simple rules: they move toward the player if they see or hear them and attack by biting, clawing, or using magic like fireballs.
The player must manage supplies of ammunition, health, and armor. Weapons and supplies can be found in levels or collected from defeated enemies, including a pistol, shotgun, chainsaw, plasma rifle, and BFG 9000. Players also face hazards like toxic waste pits, lowering ceilings, and locked doors that require keys or switches. Power-ups include health or armor boosts, a map computer, temporary invisibility, a suit to protect against poison, invulnerability, or a powerful melee mode. Cheat codes let players unlock all weapons, walk through walls, or become invulnerable.
Two multiplayer modes are available over a network: cooperative, where two to four players team up to complete the campaign, and deathmatch, where two to four players compete to kill opponents as many times as possible. Multiplayer was originally only playable on local networks, but a four-player online mode became available one year after the game launched 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 in a later version called The Ultimate Doom, which was released two years after the original Doom. The game's story includes few plot details, with most information provided through the instruction manual and text descriptions between episodes.
In the future, a marine is sent to Mars for a difficult job after he disobeys a commander who ordered his unit to attack civilians. The Union Aerospace Corporation, which manages radioactive waste sites on Mars, allows the military to test secret teleportation technology that becomes dangerous. A base on Phobos urgently asks for military help, while Deimos vanishes completely. The marine joins a group to protect Phobos. He follows orders to secure the perimeter, but his entire team is destroyed. With no way to leave Phobos 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 evil forces in military and waste facilities on Phobos. The episode ends with the marine defeating two strong demons guarding a teleporter to the Deimos base. After the battle, the marine uses 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 that the moon is floating above a fiery place called hell and descends to the surface. In "Inferno," the marine fights through hell itself and destroys a powerful spider-like demon that planned the attack on the moons. When a portal to Earth opens, the marine enters and finds that Earth has been invaded. "Thy Flesh Consumed" shows the marine attacking the invaders on Earth, preparing the way for the next game, Doom II.
Development
Id Software released Wolfenstein 3D in May 1992. Later called the "grandfather of 3D shooters," it helped make the genre popular and known for fast action and new technology. When most of the studio began working on more episodes for Wolfenstein, id co-founder and lead programmer John Carmack instead started researching a new game. After releasing Wolfenstein 3D: Spear of Destiny in September 1992, the team began planning their next project. They were tired of Wolfenstein and wanted to create another 3D game using a new engine Carmack was developing. Co-founder and lead designer Tom Hall suggested a new game in the Commander Keen series, but the team decided that the Keen gameplay was not a good match for Carmack's fast-paced 3D engine. The other co-founders, designer John Romero and lead artist Adrian Carmack (no relation to John Carmack), wanted to create something with a darker style than the Keen games.
John Carmack imagined a game about using technology to fight demons, inspired by a Dungeons & Dragons campaign the team played. This campaign also influenced the design of Quake (1996) and Daikatana (2000). The team wanted to combine the styles of the movies Evil Dead II and Aliens. The game's working name was Green and Pissed, but Carmack renamed it Doom after a line from the 1986 movie The Color of Money: "What you got in there?" / "In here? Doom."
The team agreed to develop Doom, and work began in November 1992. The initial team had five members: 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," inspired by noises from a nearby dental office. They also decided to stop working with their previous publisher, Apogee Software, and self-publish Doom because they believed they could earn more money that way.
In November, Hall created a design document he called the "Doom Bible," which described the game's story, background, and goals. His plan was a science fiction horror story where scientists on the Moon open a portal to an alien invasion. Over time, the player discovers the aliens are demons, and hell slowly takes over the game's levels. John Carmack disliked the story and thought having a story was unnecessary, saying it was like having a story in a porn movie: "expected to be there, but not important." Instead, he wanted to focus on technology, moving away from Wolfenstein's level-based structure to create a fast, continuous world. Hall disagreed, but the rest of the team supported Carmack. Hall rewrote the "Doom Bible" to match Carmack's ideas, but the team later realized Carmack's vision was too advanced for the hardware available, forcing Hall to revise the document again.
In early 1993, id released a press statement about Hall's story of fighting demons "knee-deep in the dead." The press release highlighted the new 3D engine John Carmack had created and mentioned features like multiplayer, even though they were not yet designed. Early versions of the game followed the "Doom Bible," and a "pre-alpha" version of the first level included Hall's introductory scene. Initial versions also kept Wolfenstein's arcade-style scoring, but this was later removed because it clashed with Doom's tone. The studio tested other systems, like lives, inventory, and a complex interface, but eventually removed them.
Soon, the "Doom Bible" was rejected. John Romero wanted a game even "more brutal and fast" than Wolfenstein, leaving no room for Hall's character-driven story. The team also felt the story focused too much on realism and not enough on fun gameplay. They decided they did not need a design document at all. Some ideas remained, but the story was dropped, and most of the design was removed. By early 1993, Hall created levels that became part of an internal demo. However, Carmack and Romero disliked the military-style architecture in Hall's designs. Romero believed the flat, boxy levels did not show off the engine's capabilities and began creating his own, more abstract levels, which the team saw as an improvement.
Hall became upset with how little influence he had as the lead designer and how much he had to argue with Carmack over changes like flying enemies. He began spending less time at work. The other developers felt Hall was not aligned with the team's vision and became a problem. In July, the other founders of id fired Hall, who later worked for Apogee. He was replaced by Sandy Petersen in September, ten weeks before the game's release. Petersen later said Carmack and Romero wanted to hire other artists, but Kevin Cloud and Adrian Carmack disagreed, believing 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 with different goals: the team believed Petersen's designs were more technically varied, while Romero's were more visually interesting. In late 1993, a month before release, John Carmack added multiplayer. After coding the multiplayer feature, the team began playing 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 mostly written 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 separated the game's design from the engine, allowing changes to the design without altering the engine code. Carmack created this system so fans could easily modify the game, inspired by fan-made changes to Wolfenstein 3D. He also released a map editor to support this.
Unlike Wolfenstein, which had flat, boxy levels, the Doom engine allowed walls and floors at any angle or height but did not support vertical stacking. The lighting system adjusted the color palette of surfaces directly. Instead of using ray tracing to calculate how light traveled, the game determined the "light level" of a small area based on its brightness and changed the color palette of that area's textures to mimic darkness. This same system made distant surfaces appear darker than close ones.
Romero found new ways to use Carmack's lighting engine, such as strobe lights. He also programmed features like 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 portion of a level. Taylor, along with programming other features, added cheat codes for development and left them in the game for players.
Adrian Carmack was the lead artist for Doom.
Release
Id Software planned to release Doom for computers that used the DOS operating system. They created a system to distribute the game before its launch. Jay Wilbur, who was hired as CEO and the only member of the business team, planned how to market and distribute Doom. Id Software would earn the most money by selling copies directly to customers, up to 85% of the planned $40 price. To maximize sales, Wilbur focused on the shareware market, where people could try a free version of the game. He believed mainstream media would not be interested in Doom, so he 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 the total development cost 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 energized that he would sometimes faint. 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 online throughout the year. As excitement grew, id received many calls from people interested in the game or upset about the delayed release. At midnight on December 10, 1993, after 30 hours of testing, the team uploaded the first episode of Doom to the internet. Players began sharing the game widely, but the upload failed because too many users tried to access the FTP server at the University of Wisconsin–Madison. The network administrator had to increase the server’s capacity and then disconnect all users to free space. After 30 minutes, the upload completed, but 10,000 people tried to download the game at once, crashing the university’s network.
Soon after Doom’s release, university networks banned multiplayer games because too many players overwhelmed their systems. The next morning, John Carmack quickly released a patch to fix complaints about network congestion. Administrators still had to create rules to prevent networks from crashing due to the game’s popularity.
In 1995, id released an expanded version of Doom for retail stores, including a fourth episode of levels. This version, called The Ultimate Doom, was published by GT Interactive. Doom was later ported to many other platforms, including Linux, Windows, and various consoles. The first unofficial port to Linux was created 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. Microsoft CEO Bill Gates briefly considered buying id, but the company declined. Microsoft then created its own licensed version of Doom, led by Gabe Newell. A promotional video for Windows 95 showed Gates digitally inserted 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. Some of these platforms, such as the PlayStation 5 and Xbox Series X/S, received expanded versions of Doom and Doom II in 2024. The 2016 "IDKFA" arranged soundtrack by Andrew Hulshult was also included in some ports. Some versions of the game had fewer levels than others. For example, the 32X port, 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.
In 1997, the source code for Doom was released under a non-commercial license. In 1999, it was freely shared under the GNU General Public License. Because the source code was available, Doom was unofficially ported to many platforms, including smart thermostats, pianos, and other devices. This led to the creation of a popular meme asking, "Can it run Doom?" and "It runs Doom."
Reception
When Doom was released in December 1993, it quickly became very popular. The game helped id Software make money very fast, earning a profit within one day of its release. Even though the company estimated that only 1% of people who downloaded the free version of the game later bought the full version, this was enough to earn about 100,000 dollars each day. In one day, Doom sold as many copies as the game Wolfenstein had sold in one month. By May 1994, the company reported that Doom 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 had been sold in the first year. By 2002, another person from the company said about 200,000 copies had been 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 dollars in revenue. This made Doom the fourth-best-selling computer game in the United States since 1993. By September 1999, the Ultimate Doom version had sold over 780,000 copies, and all versions combined had sold 3.5 million copies by the end of 1999. In addition, about six million people had played the free version of Doom by 2002. Other sources estimated that between 10 and 20 million people had played Doom within 24 months of its release.
Doom received strong praise from reviewers when it was first released. In April 1994, PC Gamer UK named it the third-best computer game of all time, saying it helped establish the power of the PC for arcade-style games. In August 1994, PC Gamer US named it the best computer game of all time. Doom won awards such as Best Action Adventure at Cybermania ’94 and Game of the Year in 1993 from GamesRadar UK. Computer Gaming World and PC Gamer UK also named it Game of the Year the following year.
Reviewers praised the single-player gameplay, calling it exciting and technically impressive. Some said it was so addictive that people missed sleep and appointments to keep playing. Others praised the variety of enemies and weapons, and the level design. However, some reviewers said the gameplay was repetitive and lacked depth. Others criticized the simple shooting mechanics but praised the graphics, levels, and music. One review joked that if players could talk to the enemies, it might be more interesting, and this joke became popular in video game culture.
The multiplayer mode was also praised for being intense and exciting. Some reviewers called it the best multiplayer experience available on computers.
The 3D graphics and art style were widely praised. Reviewers said the graphics were excellent and more advanced than those in other games. They also praised the atmosphere, level design, lighting, and sound effects, which created a tense and scary experience. The music was also praised for matching the game’s dark and ominous tone.
When The Ultimate Doom was released in 1995, reviews were mixed. Some reviewers said it was only a collection of new levels and not worth buying for people who already owned the original game. Others praised the difficulty of the new levels and recommended it for new players.
Early versions of Doom on other platforms, such as the Jaguar and 32X, received high scores from reviewers, who compared them favorably to the original PC version. The 1995 PlayStation version was praised for including Doom II and extra levels, but the Super NES version had weaker graphics and controls. Later versions, such as the 3DO and Sega Saturn ports, received poor reviews for worse graphics, smaller screens, and lower quality.
Legacy
Doom has been called "inarguably the most important" first-person shooter game and the "father" of the genre. Although it was not the first game in the genre, it had the greatest impact. Dan Pinchbeck in Doom: Scarydarkfast (2013) wrote that Doom’s design choices directly influenced first-person and third-person shooter games two decades later, shaped by other games released in the years between.
Doom, and to a lesser extent Wolfenstein 3D, marked 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 "paradigm shift," leading to the rise of 3D games, first-person shooters, shared technology between developers, and support for game modifications. It helped start the popularity of online multiplayer games and player-created content, and it popularized the business model 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 examples of an "online collective virtual reality" and did more than any other game to create a modern world of "networked games and gamers." PC Gamer called Doom the most influential game of all time in 2004, and in 2023 said its development was one of the best-documented in video game history.
Doom has been used in scholarly research since its release, 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 selected for preservation by the Library of Congress. In 2015, The Strong National Museum of Play inducted Doom into its World Video Game Hall of Fame as part of its first group of games.
Doom has been ranked highly in lists of the best video games ever since its release. In 1995, Next Generation said it was "the most talked about PC game ever." The PC version was ranked the third best video game by Flux in 1995 and fifth best and third most innovative by Computer Gaming World in 1996. In 2000, GameSpot ranked Doom as the second-best game ever. The following year, it was voted the number one game of all time in a poll of over 100 game developers and journalists by GameSpy, and ranked 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 ranked among 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 it was "probably the most imitated game of all time." These games were often called "Doom clones," and "first-person shooter" became the name of 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 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 engine. Games like PowerSlave (1996) and Duke Nukem 3D (1996) used the 1995 Build engine, a 2.5D engine inspired by Doom created by Ken Silverman with input from John Carmack.
After finishing Doom, id Software began working on a sequel using the same engine, 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 a retail version of Doom and Doom II. Id chose to create the sequel as a set of episodes instead of a new game, allowing John Carmack and other programmers to start work on id’s next game, 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.
Doom II was followed by an expansion pack from id, 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 by id as the standalone game Final Doom (1996). Doom and Doom II were included in the id Anthology compilation (1996). The Doom franchise has continued since the 1990s in many forms, including Doom 3 (2004), Doom (2016), and Doom Eternal (2020), along with other spin-off games, novels, a comic book, board games, and two films: Doom (2005) and Doom: Annihilation (2019).
Doom was known for its high levels of graphic violence and satanic imagery, which caused controversy. The Doom version for the 32X was one of the first games to receive a Mature 17+ rating from the Entertainment Software Rating Board because of its violent content. Doom II was the first game to be given this rating. In Germany, shortly after its release, Doom was classified as "harmful to minors" by the Federal Department for Media Harmful to Young Persons and could not be sold to children or displayed where they could see it. This classification was removed in 2011.
Doom again sparked controversy in the United States when it was discovered that Eric Harris and Dylan Klebold, who committed the Columbine High School massacre on April 20, 1999, were avid players. Harris wrote in his journal that the attack would be "like playing Doom." A rumor spread that Harris created a custom Doom level resembling the school, but no such level existed. Doom was called a "mass murder simulator" by critic and Killology Research Group founder David Grossman.
In the earliest versions of Doom, the level E1M4: Command Control included a swastika-shaped structure as a tribute to Wolfenstein 3D. The sw