4 player co-op

Drop feet first into a new way to play Halo with the cooperative campaign mode, Firefight. Form a squad of your friends over System Link or Xbox LIVE and put your skills to the ultimate test against the invading Covenant war machine for glory, high scores, and achievements. Do battle in multiple environments, on foot or in vehicles, and against increasingly difficult waves of Covenant attackers while Halo 3's skull modifiers progressively activate to up the ante.
After the Firefight, relive and review every last kill you earned and see how your high scores and stats stack up against your friends' and the community overall using Bungie.net's persistent online stats and Firefight leaderboards.

/unlocked. thought u were perma-banned

i love the firefight mode on ODST

have u ever modded cod 5 co-ops its jokes

XD