Team SWAT
From Halopedia, the Halo wiki
Team SWAT is a Halo 2 unranked Matchmaking gametype. The player has no shields, and spawns with a headshot weapon. Common starting weapons are the Battle Rifle, Covenant Carbine, or the M6C Magnum. Players do not spawn with grenades, and there are usually no weapons or grenades found on the map.
The lack of shields significantly increases the speed of the game. Headshots are usually crucial, as they can take down a person in one round or burst, compared to shooting the body, where it can take up to two or three.
Team SWAT will be arriving as a Halo 3 gametype on March 20, 2008 at 12:00 p.m. PST.