Doom is a 1993 first-person shooter game created and released by id Software for the MS-DOS computer system. It is the first game in the Doom series. Players take the role of a space marine, later known as Doomguy, who battles large groups of undead humans and demons. The game begins on the moons of Mars and ends in hell, with players moving through levels to find exits or defeat bosses. Doom was one of the first video games to use 3D graphics, though some enemies and objects were made using 2D images, a method called 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 began working on a new game focused on fighting demons, using a 3D game engine developed by lead programmer John Carmack. Initially, the game had a science fiction story written by designer Tom Hall, but this was removed later. The final version focused on action and was designed by John Romero and Sandy Petersen. Doom was released as three episodes using the shareware model, with the first episode given away for free. A retail version with an extra episode, called The Ultimate Doom, was released in 1995 by GT Interactive.
Doom was very successful and is considered one of the most important and 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 it changed how people viewed video games and helped create online gaming and communities. Doom inspired many similar games, led to a strong modding scene, and helped start speedrunning as a hobby. Its graphic violence caused controversy among many groups. 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 looks 3D, movement is limited to a 2D plane, a technique called 2.5D graphics. Enemies and objects appear as flat images that always face the player, known as billboarding. In the single-player campaign, the player controls an unnamed space marine, later called "Doomguy," as they explore military bases on the moons of Mars and in hell. To complete a level, the player must navigate through complex, maze-like areas to reach an exit room. Levels are divided into named episodes, with the final level of each featuring a boss fight.
While moving through levels, the player fights various enemies, including demons and possessed humans. Enemies often appear in large groups. Five difficulty levels change the number of enemies and the damage they cause. On the hardest difficulty, enemies move and attack faster. Enemies behave simply: 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 of ammunition, health, and armor. Weapons and ammunition can be found throughout levels or collected from defeated enemies, including a pistol, shotgun, chainsaw, plasma rifle, and the BFG 9000. Players also face obstacles like toxic waste pits, lowering ceilings, and locked doors that require keys or switches to open. Power-ups include health or armor boosts, a mapping computer, partial invisibility, a radiation suit to protect against toxic waste, invulnerability, or a super-strong melee state. Cheat codes allow players to unlock all weapons, walk through walls, or become invulnerable.
Two multiplayer modes are available over a network: cooperative, where two to four players work together to complete the campaign, and deathmatch, where two to four players compete to kill opponents as many times as possible. Multiplayer was initially only playable on local networks, but a four-player online mode became available one year after release through the DWANGO service.
Plot
The game Doom has 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 has few details, with most of the plot explained through the instruction manual and text descriptions between episodes.
In the future, a marine is sent to a remote location on Mars after disobeying orders to attack civilians. The Union Aerospace Corporation, which manages radioactive waste sites there, allows the military to test secret teleportation technology that becomes dangerous. A base on Phobos urgently asks for help, while Deimos vanishes completely. The marine joins a combat group to protect Phobos. He follows orders to secure the perimeter, but the 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 possessed humans in military and waste facilities on Phobos. The episode ends when he defeats two powerful Barons of Hell guarding a teleporter to the Deimos base. After the battle, he 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, ending with the defeat of a large cyberdemon. From a high point, he sees the moon floating above hell and descends to the surface. In "Inferno," the marine fights through hell itself and destroys a cybernetic spider-demon that planned the invasion of the moons. When a portal to Earth opens, the marine enters and finds Earth has been invaded. "Thy Flesh Consumed" shows the marine attacking Earth's invaders, preparing the way for Doom II.
Development
In May 1992, Id Software released Wolfenstein 3D. This game became known as the "grandfather of 3D shooters" because it helped make this type of game very popular. It was famous for fast action and using new technology. After releasing Wolfenstein 3D: Spear of Destiny in September 1992, the team began planning their next game. They were tired of Wolfenstein and wanted to create another 3D game using a new engine John Carmack was developing.
Tom Hall, a co-founder and lead designer, suggested a new game in the Commander Keen series. However, the team decided that the Keen games’ style was not a good match for Carmack’s fast-paced 3D engine. John Romero and Adrian Carmack, another co-founder and lead artist, wanted to create something with a darker style than the Keen games.
John Carmack had an idea for a game about using technology to fight demons. This idea came from a Dungeons & Dragons campaign the team played. The same campaign also influenced the design of Quake (1996) and Daikatana (2000). The team wanted to mix the styles of the movies Evil Dead II and Aliens. The game’s working title was Green and Pissed, but Carmack changed it to Doom after hearing a line from the 1986 movie The Color of Money.
The team agreed to develop Doom. Work began in November 1992 with 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." It described a science fiction horror story about scientists on the Moon opening a portal to an alien invasion. John Carmack disliked the story and believed games did not need detailed stories. He wanted to focus on technology instead. Hall had to change the design document several times to match Carmack’s ideas.
In early 1993, the team released a press statement about Doom. It described a game where players fight demons while "knee-deep in the dead." The press release also mentioned new features like multiplayer, which had not yet been created. Early versions of the game followed the "Doom Bible" but later changed to match the game’s tone. The team tested other systems, like lives and inventory, but removed them.
Soon, the team rejected the "Doom Bible" as a whole. John Romero wanted a game even faster and more brutal than Wolfenstein, which left little room for Hall’s story. The team also believed the story made the game too realistic and not fun enough. Most of the design was removed, and Hall created levels for an internal demo. However, Carmack and Romero disliked Hall’s level designs and replaced them with their own.
Hall felt upset because his ideas were not being used and spent less time working. The other developers believed Hall was not following the team’s vision and fired him in July 1993. He later worked for Apogee Software. Sandy Petersen replaced Hall in September 1993, ten weeks before the game was released. Petersen and Romero designed the rest of Doom’s levels. Petersen’s designs were more technically interesting, while Romero’s were more visually interesting.
In late 1993, John Carmack added multiplayer to the game. After coding multiplayer, the team played four-player games, which Romero called "deathmatch," and Cloud named killing other players "fragging." This mode was inspired by fighting games like Street Fighter II.
Doom was mostly written in the C programming language, with some parts in assembly language. The developers used NeXT computers with the NeXTSTEP operating system. Level and graphical data was stored in WAD files, which stood for "Where's All the Data?" This system allowed fans to modify the game easily.
Unlike Wolfenstein, which had flat, boxy levels, Doom allowed walls and floors at any angle or height. However, it did not support vertical stacking of areas. The game used a lighting system that changed the color of surfaces based on brightness. It did not use complex calculations like ray tracing. Instead, it adjusted colors to make faraway surfaces look darker.
John Romero used the lighting system creatively, like with strobe lights. He also added features like switches and moving platforms. When complex levels caused problems, Carmack used a method called binary space partitioning to improve performance. Dave Taylor, a third programmer, added cheat codes for development and left them in the game for players.
Adrian Carmack was the lead artist.
Release
Id Software planned to publish Doom for computers that used DOS and created a distribution system before the game's release. Jay Wilbur, who was hired as CEO and the only member of the business team, planned how to market and distribute Doom. Since Id Software would earn more money by selling copies directly to customers—up to 85% of the planned $40 price—he focused on using the shareware market as much as possible. He believed that mainstream newspapers were not interested in the game and only bought one ad in any 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 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 praise, but also shared updates about the game’s development with the public through the early internet. As the game became more popular, Id received many calls from people who were interested in Doom or upset that it was delayed. At midnight on December 10, 1993, after working for 30 hours straight, the team uploaded the first episode of Doom to the internet, allowing players to share it. The team 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, causing the university’s network to crash.
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 fix 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 a larger version of Doom for the retail market with a fourth episode of levels, which was published by GT Interactive as The Ultimate Doom. Doom was also adapted for many other platforms, not made by Id Software. The first version of Doom for Linux was created in 1994 by Id programmer Dave Taylor, but it was not officially supported. 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 made its own version of Doom for Windows, led by Gabe Newell. A promotional video for Windows 95 showed Gates digitally added into the game.
Other official versions 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 versions included additional content, such as The Ultimate Doom and Doom II, which were released alongside the 2024 ports for PlayStation 5 and Xbox Series X/S. A 2016 soundtrack by Andrew Hulshult was also included in some versions. Some of these ports became popular even years after the original release. Not all versions had the same content, such as the 32X version, which 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 adapted for many platforms. These adaptations included unusual devices like smart thermostats, pianos, and even the game itself, leading to the long-running meme: “Can it run Doom?” and “It runs Doom.”
Reception
When Doom was released in December 1993, it quickly became very popular. The game made money for its creators, id, very fast. The company estimated that only 1% of people who downloaded the free version of the game bought the full version, but this was enough to earn about $100,000 each day. In one day, Doom sold as many copies as the game Wolfenstein had 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 had been sold in the first year. In 2002, another person 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. In April 1998, a report said the free version of Doom had sold 1.36 million copies in the United States and earned $8.74 million in revenue. This made Doom the fourth-best-selling computer game in the country since 1993. By September 1999, the game Ultimate Doom had sold over 780,000 copies, and all versions combined had sold 3.5 million copies by the end of 1999. By 2002, about 6 million people had played the free version of the game. Other sources estimated that 10 to 20 million people had played Doom within 24 months of its release.
Doom received high praise from reviewers. In April 1994, PC Gamer UK named it the third-best computer game of all time, saying it helped establish the PC as a strong platform for arcade-style games. PC Gamer US named it the best computer game of all time in August 1994. It 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. One magazine called it "a skull-banging, palm-sweating, blood-pounding game," while another described it as "a technically superb and thrilling 3D adventure." A reviewer said the game was so addictive that they missed sleep and appointments to keep playing. PC Zone called it the best arcade game ever, and Computer Gaming World praised the variety of monsters and weapons. Computer Gaming World also said the game was a "virtuoso performance." Some reviewers noted that the gameplay lacked complexity, calling it repetitive, while others praised the level design and fast pace. Edge praised the graphics and levels but criticized the simple shooting gameplay. A review comment—"If only you could talk to these creatures, then perhaps you could try and make friends with them"—became a joke in video game culture.
Reviewers also praised the multiplayer gameplay. 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 best arcade game.
The 3D graphics and art style received strong praise. Computer Gaming World called the graphics remarkable, and Edge said they set a new standard for 3D graphics. Other magazines praised the atmosphere, level design, lighting, and sound effects, saying they created a "claustrophobic" and "nightmarish experience." Computer Gaming World and The Mercury News also praised the music for being "ominous" and fitting the game’s setting.
When Ultimate Doom was released in 1995, reviews were mixed. PC Zone gave it a score of 90/100 for new players but only 20/100 for those who had already played the original game, calling it a "level pack" with few new features. Joystick said it had limited content and recommended it only for major fans or new players. Fusion and GameSpot praised the difficulty of new levels, with GameSpot focusing on introducing the game to new players.
Early versions of Doom received reviews similar to the original PC version. The Jaguar version was praised by VideoGames, GamePro, and Computer and Video Games, who compared it favorably to the PC version. The 32X version was also praised, though reviewers noted worse graphics and a shorter game. 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 1990s ports, such as the 3DO and Sega Saturn versions, received poor reviews for worse graphics, smaller screens, and lower quality.
Legacy
Doom is widely considered the most important first-person shooter game and is often called the "father" of the genre. Though not the first game in this category, it had the greatest influence on future games. In 2013, Dan Pinchbeck wrote that Doom's design choices directly influenced first-person and third-person shooter games even 20 years later, as seen in games released in the years following Doom.
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 image of video games in media. Historians like Tristan Donovan have called Doom a "paradigm shift," meaning it changed the way people thought about video games. It helped increase the popularity of 3D games, first-person shooters, and technology sharing between game developers. It also helped create online multiplayer games and player-made content. In 2014, Brad King and John Borland wrote that Doom was one of the first games to create a shared online experience, helping build a modern world of connected 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.
Scholars have used Doom in research about machine learning, game design, and the effects of video games on behavior. In 2026, Australian researchers used 200,000 human brain cells to train an organic computer to play Doom. In 2007, Doom was listed among the top 10 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 been ranked highly in lists of the best video games since its release. In 1995, it was called "the most talked about PC game ever." In 1995, it was ranked the third best game by Flux and fifth best by Computer Gaming World. In 2000, GameSpot ranked it the second-best game ever. In 2001, over 100 game developers and journalists voted Doom the best game of all time. It has also been ranked among the best games by many other sources, including GamesMaster, Hyper, The Independent, and 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 called "Doom clones," and the term "first-person shooter" became the genre's name 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, shared its game engine with other companies, leading to games like Heretic (1994), Hexen: Beyond Heretic (1995), and Strife: Quest for the Sigil (1996). A game called Chex Quest (1996) was made by Ralston Foods to promote cereal sales. Other games, like LucasArts' Star Wars: Dark Forces (1995), were inspired by Doom, though some were made by studying its code. Games like PowerSlave (1996) and Duke Nukem 3D (1996) used a different engine called the Build engine, which was inspired by Doom.
After finishing Doom, id Software worked on a sequel called Doom II, which was released in October 1994. Doom II became the top-selling software product in the United States in 1994, selling over 1.2 million copies in a year. A collection of new levels for Doom II, called Master Levels for Doom II (1995), included 21 official levels and over 3,000 levels made by players. Final Doom (1996) was a standalone game that combined two sets of player-made levels. Doom and Doom II were later included in the id Anthology (1996). The Doom franchise has continued with games like Doom 3 (2004), Doom (2016), and Doom Eternal (2020), as well as novels, comics, board games, and films.
Doom was known for its graphic violence and satanic imagery, which caused controversy. Doom for the 32X was the first game to get a Mature 17+ rating from the Entertainment Software Rating Board. In Germany, Doom was banned from being sold to children and displayed in places where children could see it until 2011.
Doom became controversial again in the United States when it was discovered that Eric Harris and Dylan Klebold, the shooters in the Columbine High School massacre in 1999, were fans of the game. Harris wrote in his journal that the attack would be "like playing Doom." A rumor spread that Harris made a custom Doom level resembling his school, but no such level existed. Critics called Doom a "mass murder simulator."
In early versions of Doom, a level called E1M4: Command Control had a swastika-shaped structure as a tribute to Wolfenstein 3D. This was later removed at the request of a military veteran.
Doom's popularity and innovations created a lasting community. The deathmatch mode, which allowed players to compete in multiplayer battles, was a major factor in its success. Doom was the first game to use the term "deathmatch" and introduced many players to fast-paced multiplayer combat.
Another key feature of Doom was its WAD files, which let players create new levels and modify the game. John Carmack and other developers supported modding, even though some employees worried about legal and commercial issues.