Wolfenstein
Silas Warner, an American programmer and an employee of software company Muse Software, was a pioneer of early video game development, especially the stealth genre. He had access to computers in college, and when he worked for the IBM Mainframe architectures before joining Muse Software. The computer he used for game-development, P.L.A.T.O., was one of the firsts with multiple functioning terminals and an example of early computer networks. Warner developed, with P.L.A.T.O., a series of classic video games like his flight simulator and arcade shooter. Inspired by the arcade shooter video game "Berzerk" and the 1961 war film "Guns of Navarone", he developed "Castle Wolfenstein", a stealth-adventure video game in which the player controls an unnamed American prisoner of war as he steals German files containing secret war plans, while avoiding, disarming or at times killing hostile guards and trying to escape the fortified Nazi stronghold 'Castle Wolfenstein', set in World War II. The game was published in 1981 by Warner's company M.U.S.E. Inc. (Muse Software).
Development of Doom
Following the release of "Spear of Destiny" and the completion of the "ShadowCaster" engine, id Software discussed what their next title 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.'"