Doom, a first-person shooter game by id Software, was released in December 1993 and is considered one of the most significant and influential video games in history. Development began in November 1992, with programmers John Carmack and John Romero, artists Adrian Carmack and Kevin Cloud, and designer Tom Hall. Late in development, Hall was replaced by Sandy Petersen and programmer Dave Taylor joined. The music and sound effects were created by Bobby Prince.
The Doom concept was proposed in late 1992, after the release of Wolfenstein 3D and its sequel Spear of Destiny. John Carmack was working on an improved 3D game engine from those games, and the team wanted to have their next game take advantage of his designs. Several ideas were proposed, including a new game in their Commander Keen series, but John proposed a game about using technology to fight demons inspired by the Dungeons & Dragons campaigns the team played. The initial months of development were spent building prototypes, while Hall created the Doom Bible, a design document for his vision of the game and its story; after id released a grandiose press release touting features that the team had not yet begun working on, the Doom Bible was rejected in favor of a plotless game with no design document at all.
Over the next six months, Hall designed levels based on real military bases, Romero built features, and artists Adrian Carmack and Cloud created textures and demons based on clay models they built. Hall's level designs, however, were deemed uninteresting and Romero began designing his own levels; Hall, increasingly frustrated with his limited influence, was fired in July. He was replaced by Petersen in September, and the team worked increasingly long hours until the game was completed in December 1993. Doom was self-published by id on December 10, 1993, and immediately downloaded by thousands of players.
Design
Concept In May 1992, id Software released Wolfenstein 3D. It is often referred to as the "grandfather" of first-person shooters, setting expectations for fast-paced action and new technology, and greatly increased the genre's popularity. Immediately following its release, most of the team began work on a set of new Wolfenstein episodes, Spear of Destiny. As the episodes used the same game engine as the original game, id co-founder and lead programmer John Carmack instead focused on technology research for the company's next game, just as he had experimented with creating a 3D game engine prior to the development of Wolfenstein 3D. Between May and Spear of Destinys release in September 1992, he created several experimental engines, including one for a racing game, before working on an enhanced version of the Wolfenstein engine to be licensed to Raven Software for their game ShadowCaster. For this engine, he developed several enhancements to the Wolfenstein engine, including sloped floors, textures on the floors and ceilings in addition to the walls, and fading visibility over a distance. The resulting engine was much slower than the Wolfenstein one, but was deemed acceptable for an adventure game like ShadowCaster.
Following the release of Spear of Destiny and the completion of the ShadowCaster engine, id Software discussed what their next game would be. They wanted to create another 3D game using Carmack's new engine as a starting point, but were largely tired of Wolfenstein. Lead designer Tom Hall was especially weary of it, and pushed for the team to make another game in the Commander Keen series; the team had created seven episodes in the series in 1990–91 as their first games, but the planned third set of episodes had been dropped in favor of Wolfenstein 3D. While Carmack was initially interested in the idea, the rest of the team was not. They collectively felt that the platforming gameplay of the series was a poor fit for Carmack's fast-paced 3D engines, and especially after the success of Wolfenstein were interested in pursuing more games of that type. Additionally, the other two co-founders of id were not interested in creating another Keen game: John Romero, the designer of Wolfenstein, was not interested in doing another "cutesy" game, and lead artist Adrian Carmack preferred to create art in a darker style than the Keen games. John Carmack soon lost interest in Keen idea as well, instead coming up with his own concept: a game about using technology to fight demons, inspired by the Dungeons & Dragons campaigns the team played, combining the styles of Evil Dead II and Aliens. The concept originally had a working title of "Green and Pissed", which was also the name of a concept Hall had proposed prior to Wolfenstein, but Carmack soon named the proposed game after a line in the film The Color of Money: "'What's in the case?' / 'In here? Doom.'"
The team agreed to pursue the Doom concept, and development began in November 1992. The initial development team was composed of five people: programmers John Carmack and John Romero, artists Adrian Carmack and Kevin Cloud, and designer Tom Hall. They moved offices to a dark office building, which they named "Suite 666", and drew inspiration from the noises coming from the dentist's office next door. They also cut ties with Apogee Software, who had given them the initial advance money for creating their first game, Commander Keen in Invasion of the Vorticons, and through which they had published the shareware versions of their games to date. While they had a good personal relationship with owner Scott Miller, they felt that they were outgrowing the publisher. Cloud, who was involved in id's business dealings, pushed for id to take over shareware publishing duties themselves after investigating and finding that Apogee was unable to reliably handle the volume of customers buying id's games through Apogee. He convinced the others that the increased sales revenue would make up for the problems of handling their own publishing. The two companies parted amicably, and Doom was set to be self-published.
Development
Early in development, rifts in the team began to appear. Hall, who despite having wanted to develop a different game remained the lead designer and creative director for the company, did not want Doom to have the same lack of plot as Wolfenstein 3D. At the end of November he delivered a design document, which he named the Doom Bible, that described the plot, backstory, and design goals for the project. His design was a science fiction horror concept wherein scientists on the Moon open a portal from which aliens emerge. Over a series of levels the player discovers that the aliens are demons; Hell also steadily infects the level design as the atmosphere becomes darker and more terrifying. While Romero initially liked the idea, John Carmack not only disliked it but dismissed the idea of having a story at all: "Story in a game is like story in a porn movie; it's expected to be there, but it's not that important." Rather than a deep story, John Carmack wanted to focus on the technological innovations, dropping the levels and episodes of Wolfenstein in favor of a fast, continuous world. Hall disliked the idea, but Romero sided with Carmack. Although John Carmack was the lead programmer rather than a designer, he was becoming seen in the company as the most important source of ideas; the company considered taking out key person insurance on Carmack but no one else.
Hall spent the next few weeks reworking the Doom Bible to work with Carmack's technological ideas, while the rest of the team planned how they could implement them. His adjusted vision for the plot had the player character assigned to a large military base on an alien planet, Tei Tenga. At the start of the game, as the first of four player character soldiers, named Buddy, played cards with the others, scientists on the base accidentally open a portal to Hell, through which demons poured through, killing the other soldiers. He envisioned a six episode structure with a storyline involving traveling to Hell and back through the gates which the demons used, and the destruction of the planet, for which the players would be sent to jail. Buddy was named after Hall's character in a Dungeons & Dragons campaign run by John Carmack that had featured a demonic invasion. Hall was forced to rework the Doom Bible again in December, however, after John Carmack and the rest of the team had decided that they were unable to create a single, seamless world with the hardware limitations of the time, which contradicted much of the new document.
At the start of 1993, id put out a press release by Hall, touting Buddy's story about fighting off demons while "knee-deep in the dead", trying to eliminate the demons and find out what caused them to appear. The press release proclaimed the new game features that John Carmack had created, as well as other features, including multiplayer gaming features, that had not yet been started on by the team or even designed. The company told Computer Gaming World that Doom would be "Wolfenstein times a million!" Early versions were built to match the Doom Bible; a "pre-alpha" version of the first level included the other characters at a table and movable rolling chairs based on ones at the id office. Initial versions also retained "arcade" elements present in Wolfenstein 3D, like score points and score items, but those were removed early in development as they felt unrealistic and not in keeping with the tone. Other elements, such as a complex user interface, an inventory system, a secondary shield protection, and lives were modified and slowly removed over the course of development.
Soon, however, the Doom Bible as a whole was rejected: Romero wanted a game even "more brutal and fast" than Wolfenstein, which did not leave room for the character-driven plot Hall had created. Additionally, the team did not feel that they needed a design document at all, as they had not created one for prior games; the Doom Bible was discarded altogether. Several ideas were retained, including starting off in a military base, as well as some locations, items, and monsters, but the story was dropped and most of the design was removed as the team felt it emphasized realism over entertaining gameplay. Some elements, such as weapons, a hub system of maps, and monorails later appeared in later Doom or id games. Work continued, and a demo was shown to Computer Gaming World in early 1993, who raved about it. John Carmack and Romero, however, disliked Hall's military base-inspired level design. Romero especially felt that while John Carmack had originally asked for realistic levels as they would make the engine run quickly, that Hall's level designs were uninspiring. He felt that the boxy, flat levels were too similar to Wolfensteins design, and did not show off everything the engine could do. He began to create his own, more abstract levels, beginning with a curving staircase into a large open area in what became the second level of the final game, which the rest of the team felt was much better.