From Halopedia, the Halo wiki
Halo Chess is a gametype variant falling under Insane in Halo: Reach. Like other variants of Insane, Chess has its own unique gameplay mechanics.
To create a map capable of playing chess a single hill marker must be placed in Forge with the label BOARD_CENTER. A full chess board with NPCs for chess pieces will then be automatically generated when playing on the map variant under the Halo Chess gametype. Currently the BOARD_CENTER label is only available with Halo Chess chosen in the Forge lobby and while editing Forge World, Tempest, or Anchor 9.
White Team uses the Noble Team character models, but with white primary color, while Black Team uses the different Sangheili classes in their Campaign color schemes. The characters replace the piece that they are most similar to, and in some cases have a different weapon to better fit that role.
- Pawns - S-B312s with MA37s / Minors with Plasma Repeaters
- Rooks - Jun-A266s with SRS99s / Rangers with Focus Rifles
- Knights - Emile-A239s with M45s / Spec-Ops with Energy Swords
- Bishops - Unknown female Spartans with M319s / Zealots with Concussion Rifles
- Queen - Kat-B320 with an M41 SSR MAV/AW / Ultra with a Plasma Launcher
- King - Carter-A259 with a white Noble Team flag / General with a black flag
Glitches and bugs
Because Chess was created by altering the game's coding, there are a number of small glitches and bugs, though most of them do not affect gameplay.
- While there is a Check function, there is no Checkmate, and when in Check a player is not forced to move his/her King, therefore players must either play with honor rules or play to kill the King. This is one of the main reasons it will not appear in Matchmaking.
- Once a player has taken control of a unit, that character will become all white with a silver visor if they are playing as Spartans, or an inversion of the player's primary colour if they are playing as Sangheili, and will remain that way for the duration of the game. This makes the Sangheili very difficult to tell apart at a glance once they are all the same color.
- During mid-game some pieces may gain (and later lose) a "good" standard of active camouflage which can become confusing if either of the players were not keeping track of the board.
- When in control of a Spartan, they will have the arms of an armorless Sangheili in first-person.
- All Spartans have female voices, regardless of the character.
- As it would seem that Jorge was unable to be used in this game mode, most likely because of his size and/or use of an M247, the Bishops are instead represented by all white female Spartans wearing fully default armor, except for an Air Assault helmet and a silver visor. It is unknown who they are supposed to be, if anyone.
- The Chess game type was alluded to a year earlier in a Bungie April Fool's ViDoc, Zugzwang Evolved.