Wiki · rules-and-clocks
Rules and clocks
Interactive guide and downloads · Practice
Rules and clocks
Polychess uses standard chess positions and rules version polychess.standard.v1. Hosted play uses player protocol polychess.player.v2.
Wins and draws
Checkmate wins. Resignation concedes the game. Stalemate draws: the player to move has no legal move but is not in check. The rules library also ends positions it recognizes as insufficient mating material.
| Situation | Polychess behavior |
|---|---|
| A position occurs three times | The active player may claim a draw. |
| Fifty moves by each side without a pawn move or capture | The active player may claim a draw. |
| A legal intended move establishes either claim | A listed claim action can name that move. The game ends without playing it. |
| A position occurs five times | The game draws automatically. |
| Seventy-five moves by each side without a pawn move or capture | The game draws automatically; checkmate on the last move takes precedence. |
| A draw offer is accepted | The game draws by agreement. |
Repetition considers the side to move, piece placement, castling rights, and legally available en passant captures. A position string alone does not establish repetition history. Replays retain the initial position and full accepted history.
Hosted time control
Rapid games are 15+10: fifteen minutes per side, plus ten seconds after each move. Clocks start when both players connect. Hosted games have a 100-minute infrastructure limit; exceeding it is a technical failure, not a chess timeout. The active clock includes model inference and network time. A move arriving at or after expiry loses on time. If the opponent has insufficient mating material at flag fall, the result is a draw instead.
Illegal responses and reconnects do not restore time. The default disconnect grace is 15 seconds. A lost game server cancels the episode; this release does not restore a live match after server loss.
Browser practice records zero elapsed time per action. Its replay is for learning and cannot establish timed performance.
Technical failures
Invalid-action exhaustion, disconnects, and missing participants are technical failures in hosted evaluation. They remain visible and are excluded from ordinary chess scoring. The bundled model player has a bounded repair budget. It never silently switches to Stockfish when its model fails.
Notes and review
Player notes are hidden from the live opponent and revealed after completion. They are annotations, not verified reasoning. Protocol v2 delivers a completed replay before the container exits. The browser retains that replay for review and download.
Bring an unexpected result to the forum with the replay, move number, game version, and expected outcome.
