Shogi Rules

Board and setup

• The board has 9×9 = 81 squares, all the same colour.
• Each player starts with 20 pieces: 1 king, 2 gold, 2 silver, 2 knights, 2 lances, 1 rook, 1 bishop and 9 pawns.
• Pieces are wedge-shaped; the point shows which way the piece faces and who owns it.
• Sente (Black) moves first.

Promotion (Nari)

• Each player's promotion zone is the last three ranks on the opponent's side.
• Any piece except the king and gold may promote when it moves into, within or out of that zone.
• A promoted piece is flipped over (red characters). Promotion cannot be undone.
• A pawn or lance reaching the last rank, or a knight reaching the last two ranks, must promote.

Drops (Uchi)

• A captured piece is not removed from play; it goes to the capturing player's hand.
• Instead of moving, a player may drop a piece from hand onto any empty square.
• Dropped pieces land unpromoted; even inside the promotion zone they can only promote on a later move.
• A pawn or lance cannot be dropped on the last rank, nor a knight on the last two ranks.

Illegal moves

• Nifu (二歩): you may not have two unpromoted pawns in the same file.
• Uchifuzume (打ち歩詰め): you may not checkmate by dropping a pawn. Checkmating by moving a pawn on the board is allowed.
• You may not make a move that leaves your own king in check.

End of the game

• A checkmated player loses. A player with no legal moves also loses (there is no stalemate).
• Sennichite (千日手): if the same position occurs four times the game is a draw; a player causing it with perpetual check loses.
• Jishōgi: if both kings enter the opposite promotion zones and cannot be mated, the result is decided by counting pieces.

How our game applies the rules

Our game automatically prevents moves that leave your king in check, as well as nifu and uchifuzume, and only highlights legal squares. Sennichite and jishōgi are not yet adjudicated automatically.