Doom (1993)

Doom is a first-person shooter presented with 3D graphics. 5D graphics. The enemies and objects are 2D sprites rendered at fixed angles, known as billboarding. In the single-player campaign mode, the player controls an unnamed space marine—later unofficially termed "Doomguy"—through military bases on the moons of Mars and in hell.

To finish a level, the player must traverse through labyrinthine areas to reach a marked exit room. Levels are grouped into named episodes, with the final level of each focusing on a boss fight.

Doom is divided into three episodes, each containing eight main levels: "Knee-Deep in the Dead", "The Shores of Hell", and "Inferno". A fourth episode, "Thy Flesh Consumed", was added in an expanded version, The Ultimate Doom, released two years after Doom. The campaign contains very few plot elements, with a minimal story presented mostly through the instruction manual and text descriptions between episodes.

In the future, an unnamed marine is posted to a dead-end assignment on Mars after assaulting a superior officer who ordered his unit to fire on civilians. The Union Aerospace Corporation, which operates radioactive waste facilities there, allows the military to conduct secret teleportation experiments that turn deadly. A base on Phobos urgently requests military support, while Deimos disappears entirely, and the marine joins a combat force to secure Phobos. He secures the perimeter as ordered while the entire response team is wiped out. With no way off the moon, and armed with only a pistol, he enters the base intent on revenge.

Id Software released Wolfenstein 3D in May 1992. Later called the "grandfather of 3D shooters", it established the genre's popularity and its reputation for fast action and technological advancement. When most of the studio began work on additional episodes for Wolfenstein, id co-founder and lead programmer John Carmack instead began technical research on a new game. Following the release of Wolfenstein 3D: Spear of Destiny in September 1992, the team began to plan their next game.

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 proposed a new game in the Commander Keen series, but the team decided that the Keen platforming gameplay was a poor fit for Carmack's fast-paced 3D engines. Additionally, the other co-founders, designer John Romero and lead artist Adrian Carmack (no relation to John Carmack) wanted to create something in a darker style than the Keen games.

Upon its release in December 1993, Doom became an "overnight phenomenon". It was an immediate financial success for id, making a profit within a day after release. Although the company estimated that only 1% of shareware downloaders bought the full game, this was enough to generate initial daily revenue of US$100,000, selling in one day what Wolfenstein had sold in one month. By May 1994, Wilbur said that the game had sold over 65,000 copies, and estimated that the shareware version had been distributed over 1 million times. In 1995, Wilbur estimated the first-year sales as 140,000, while in 2002 Petersen said it had sold around 200,000 copies in its first year.

By late 1995, Doom was estimated to be installed on more computers worldwide than Microsoft's new operating system, Windows 95. According to Wilbur, by June 1996 it had been downloaded 20 million times. 74 million in revenue in the United States. This led PC Data to declare it the country's 4th-best-selling computer game since 1993.

Doom has been termed "inarguably the most important" first-person shooter, as well as the "father" of the genre. Although not the first in the genre, it was the game with the greatest impact. Dan Pinchbeck in Doom: Scarydarkfast (2013) noted the direct influence of Doom's design choices on those of first-person and third-person shooter games two decades later, as influenced by the games released in the intervening years.

Doom, and to a lesser extent Wolfenstein 3D, has been characterized as "mark[ing] a turning point" in the perception of video games in popular culture, with Doom and first-person shooters in general becoming the predominant perception of video games in media. Historians such as Tristan Donovan in Replay: The History of Video Games (2010) have termed it as causing a "paradigm shift", prompting the rise in popularity of 3D games, first-person shooters, licensed technology between developers, and support for game modifications. It helped spark the rise of both online multiplayer games and player-driven content generation, and popularized the business model of online distribution. In their book Dungeons & Dreamers: A Story of how Computer Games Created a Global Community in 2014, Brad King and John Borland claimed that Doom was one of the first widespread instances 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 proclaimed Doom the most influential game of all time in 2004, and in 2023 said its development was one of the most well-documented in the history of video games.