4-Player Chess Rules

The complete ruleset for team chess on 4chess. If you already know standard chess, you only need to learn the team-specific rules — everything else works exactly as you'd expect.

1. The board and pieces

4chess is played on a standard 8×8 chessboard with the usual 32 pieces — 16 White and 16 Black — arranged in the normal starting position. There are no extra pieces, special squares, or board modifications. Each piece moves and captures exactly as in classical chess: pawns, knights, bishops, rooks, queens, and kings all follow their familiar rules, including castling, en passant, and pawn promotion.

2. Teams

Four players are divided into two teams of two:

• White team: players W1 and W2, who jointly control all White pieces.
• Black team: players B1 and B2, who jointly control all Black pieces.

Teammates share a single army and a single King. On their turn, either teammate may move any piece of their colour.

3. Turn order

Turns proceed in a fixed, repeating order that alternates between teams: W1 → B1 → W2 → B2 → W1 → … Each player makes exactly one legal move on their turn. Teammates never move twice in a row; an opponent always moves between a team's two players.

4. Check and checkmate

When a King is under attack, it is in check and must be addressed immediately by the player whose turn it is. A teammate cannot respond to a check on another player's behalf — only the player to move can.

If a King is in check and the player to move has no legal way to escape, it is checkmate. The team whose King is checkmated loses, and the game ends instantly. Checkmating just one of the two enemy Kings is enough to win the game for your team.

5. Winning and losing

A team wins when any of the following happens to the opposing team:

• One of their Kings is checkmated.
• Their team resigns.
• Their shared clock runs out of time.

6. Draws

A game is drawn under the standard chess conditions:

• Stalemate: the player to move has no legal move but is not in check.
• Insufficient material: neither side has enough material to force checkmate.
• 50-move rule: no capture or pawn move has been made in the last 50 moves.

7. The team clock

Each team plays against a single shared clock. A team's clock runs only during that team's turns (either teammate). If a team's clock reaches zero, that team loses on time. Supported time controls are Bullet (3 min), Blitz (5 min), Rapid (10–15 min), and Freestyle (untimed).

8. Special team rule: friendly captures

Unlike standard chess, you may capture your own teammate's pieces when it benefits the team — for instance to open a line, sacrifice for tempo, or remove an obstructing piece. Use this sparingly and only with your partner's understanding.

9. Disconnections

If a player disconnects, the game pauses briefly to allow them to reconnect. If they cannot return, the match may be resolved in favour of the opposing team. Always try to finish the games you start out of respect for the other three players.

10. Fair play

Using chess engines, bots, or any external assistance is strictly forbidden in rated games. 4chess is built for honest, human competition. Accounts found cheating may have their ratings reset or be suspended.