← → ↑ ↓ = Directions
Z = A X = B
A = X S = Y
D = L C = R
enter ↵ = Start
space = Select
F8 = Load state
F5 = Save state
Only while game is active!
Doom, a science fiction/horror themed video game, has a background which is given in the game's instruction manual; the rest of the story is advanced with short messages displayed between each section of the game (called episodes), the action as the player character progresses through the levels, and some visual cues.
The player takes the role of an unnamed space marine (“Doomguy”) who has been punitively posted to Mars after assaulting his commanding officer, who ordered his unit to fire on civilians. The Martian space marine base acts as security for the Union Aerospace Corporation, a multi-planetary conglomerate, which is performing secret experiments with teleportation by creating gateways between the two moons of Mars, Phobos and Deimos.
Being a first-person shooter, Doom is experienced through the eyes of the main character. This character is not named throughout the game.
In order for the game to be completed, the marine must fight through Phobos, Deimos, and then Hell itself, each presented as an episode containing eight distinct levels, along with an optional ninth hidden level for each one.
The game does not use the Doom engine, but features a custom engine, known as the Reality engine, programmed by Randy Linden.