Halo 1 and 2 4 player Coop

Halo: Reach on Steam

Halo 3, four player co-op - 2007 : r/halo

Halo: The Master Chief Collection – 4 Player Co-op in Halo 1 and 2 “Is Further Down the List” of Priorities for 343 Industries

Best Halo games

Co-Optimus - FAQ - Halo 4 Co-Op FAQ

Halo 2 - Wikipedia

4-Player Co-op Glitch, Halo Alpha

Halo 4: Splitscreen Multiplayer Gameplay - How to Unlock Not Some Recruit Anymore Achievement

The state of split-screen gaming, fall 2016 - The Verge

Halo: Infinite has 2-player split-screen and 4-player online co-op

Halo Infinite Campaign Co-Op, Forge Beta, And More Arrive In November - Game Informer

Image 4 - Halo 3 - 4 Player Splitscreen Co-Op Campaign Mod for Halo 3 - Mod DB

4-Player Co-op Glitch, Halo Alpha