Game Rules

Hidden identities

Kings begin visible. Each side’s other pieces are shuffled into hidden identities. Until a hidden piece moves, it looks and moves like the piece normally starting on that square. Its first move reveals its true identity to both players. Checks, checkmate, and draws follow chess rules.

Capturing a hidden piece

When a hidden piece is captured, only the capturing player learns what it was. That private knowledge is part of the game.

Special moves

Castling: The king can castle with the piece that looks like a rook in its original corner, even if that piece is secretly another type. Neither piece may have moved, the path must be clear, and the king cannot start, pass through, or land in check. The corner piece reveals its true identity during castling.

En passant is possible only after a real pawn moves two squares; if the moving piece was hidden, it must reveal as a pawn. The capture must be made on the opponent’s next move.

Promotion: A pawn that reaches the last rank must be promoted to a queen, rook, bishop, or knight. If a hidden piece reveals as a pawn only after landing there, you choose the promotion then.

Pawn revealed on the back rank

A hidden piece can reveal as a pawn on its own back rank, for example during castling. From the back rank, it can move only one square forward. After reaching the usual pawn starting rank (rank 2 for White or rank 7 for Black), its next forward move may be one or two squares if the path is clear. After that, it moves one square forward at a time.

Online clocks and results

In online games, the server controls clocks and records the result. Rated games change both players’ ratings. Automatic matchmaking first looks for a person, then may seat a clearly marked Bot.