Team Slayer (Playlist)
- "Straight up Team Slayer games on varied maps. Work with your team to outkill your opponents."
- —In-game description for Halo 3's ranked Team Slayer playlist
Typically, eight players are divided into two teams of four each (although three on three matches are possible if two parties of three are present). The game modes in this playlist are team-based Slayer games. In the early days of Halo 3 matchmaking, Shotty Snipers was especially prevalent, but was eventually made rarer due to player complaints, and ultimately removed altogether along with its counterpart Team Snipers (which now has its own playlist).
Any players on the winning team gain experience and may advance their level, while those on the losing team do not gain experience and will usually level down. Due to this fact, partying up with skilled teammates makes this one of the easiest ways to improve your Trueskill rank. Partying with a better player can backfire, however, if the other team is much too skilled for people on your team to compete with, then one only one or two of your teammates will be able to hold their own against similarly ranked players to them. This results in the other players on your team usually performing poorly against more skilled foes, and your team will most likely lose.
 Maps Played in Halo 3
Note: All maps have equal chance of being selected.
- High Ground
- Snowbound (HC) - Shotgun and Spartan Laser removed. Sniper moved to lower caves.
- Boundless - Snowbound variant with shield doors removed.
- The Pit
- Pit Stop - The Pit variant with inaccessible spawn hives.
- Foundry - Part of the Heroic Map Pack.
- Smashed - Symmetrical Foundry variant for Slayer and CTF.
- Standoff - Part of the Heroic Map Pack.
- Blackout - Part of the Legendary Map Pack.
- Ghost Town - Part of the Legendary Map Pack.
- Assembly - Part of the Mythic Map Pack.
- Orbital - Part of the Mythic Map Pack.
- Sandbox - Part of the Mythic Map Pack.
- Pantheon - Community Sandbox variant by JoeSki73
- Vindictive - Symmetrical Sandbox ground level map variant.
- Tundra - Symmetrical Sandbox crypt level map variant.
- Wastelands - Symmetrical Sandbox ground level map variant.
- Reminiscent - Community Sandbox variant by Mini Waz.
- Citadel - Available on the Halo 3: Mythic disk.
- Heretic - Available on the Halo 3: Mythic disk.
 Maps played in Halo: Reach
- Anchor 9
- Sword Base
- The Cage
 Gametypes played in Team Slayer
 Halo 3
- Team Slayer (73.6%) - First team to 50 kills wins. 12 minute match time limit.
- Team BRs (26.4%) - First team to 50 kills wins. Players spawn with Battle Rifles and Assault Rifle secondary weapons. 12 minute match time limit.
 Halo: Reach
- Team Slayer - First team to 50 kills wins. 12 minute match time limit.
- Slayer Pro - First team to 50 kills wins. Players only have Sprint, and choose between a DMR and Needle Rifle. 12 minute match time limit.
- Slayer DMRs - First team to 50 kills wins. Players have DMRs as primary weapon. 12 minute match time limit.
- Elite Slayer - First team to 50 kills wins. Players spawn as Elites with Elite load outs. 12 minute match time limit.