Ironically, little is known about the Doom Trooper, the main character of one of the most widely known computer game series ever: Doom. Most know him by little things, such as the sound of his voice when he's injured, his many facial expressions, and the blood that gradually covers his face as he's wounded. They also know his iconic green suit, as seen in the Doom title screen and on the bodies of Space Marines scattered about the various levels.
Transferred to a radioactive waste facility on Mars after assaulting a superior officer, the Doom Trooper spends his days watching movies until, one day, disaster strikes. Monsters spring from the inter-space gateways used for teleportation between Mars's moons, and begin wreaking havoc in the bases there. Being part of the sparse military force on the planet, the Doom Trooper is sent to defend what he can.
The series has been accused of inspiring many violent acts over the past decade since the release of its first installment, Doom, in 1993. The game sold successfully, however, and a sequel was released only the following year. After a long ten-year wait, an acclaimed third installment, Doom 3, was released, featuring a re-telling of the original story.
The Doom Trooper appears outside of the Doom series on rare occasions, including Quake III Arena and Duke Nukem 3D.