Doom 3 is a science fiction horror video game developed by id Software and published by Activision. The game is a reboot of the Doom franchise, disregarding the storylines of the previous Doom video games. Doom 3 is set in 2145 on Mars, where a military-industrial conglomerate has set up a scientific research facility to develop fields such as teleportation, biological research and advanced weapons design. However, the teleportation experiments inadvertently open a gateway to Hell, resulting in a catastrophic invasion by demons. The player, an anonymous space marine, must fight through the base and find a way to stop demons from Hell attacking Earth.
Doom 3 features an award-winning game engine, id Tech 4, which has since been licensed out to other developers, and later released under the GNU General Public License in November 2011.