Outtrigger for the Sega Dreamcast is based directly on the 1999 Japanese arcade game of the same name, though numerous additions and enhancements have been included for this console port. Players join the ranks of Interforce, an international anti-terrorist organization that tends to shoot first and ask questions later. Though designed primarily as a fast-paced first-person shooter, the game also allows for a third-person perspective on the carnage. Players blast their way through the 3D-rendered arenas, using a wide variety of weapons and collecting health packs and power-ups along the way.
The action takes place across the dozen arenas available in the arcade version of the game as well as in additional maps created exclusively for this Dreamcast version. Gamers choose to play as one of four Interforce operatives, each of which can be customized in terms of both appearance and weapon selection. Outtrigger supports several modes of multiplayer gaming, including split-screen battles and online play with up to four players competing in the same session. Chat rooms are available for online players and the game employs a special service to help match equally skilled players based on their past performances.