Standard shogi

The set-up

Nine files by nine ranks. Files are numbered 1 to 9 from sente’s right, ranks lettered a to i running away from sente. Each side has twenty men: a king, two golds, two silvers, two knights, two lances, a rook, a bishop and nine pawns.

Sente fills his back rank from file 9 to file 1 with lance, knight, silver, gold, king, gold, silver, knight, lance — L 9i, N 8i, S 7i, G 6i, K 5i, G 4i, S 3i, N 2i, L 1i. The bishop stands on 8h and the rook on 2h. Rank g is nine pawns. Gote’s army is the same shape turned around: K 5a, R 8b, B 2b, golds on 6a and 4a, silvers on 7a and 3a, knights on 8a and 2a, lances on 9a and 1a, pawns across rank c. Sente moves first.

Moving and capturing

• King: one square in any of the eight directions.
• Rook: any distance along a rank or file, not jumping.
• Bishop: any distance along a diagonal, not jumping.
• Gold: one square orthogonally in any direction, or one square diagonally forward. Never diagonally backwards.
• Silver: one square straight forward, or one square on any of the four diagonals.
• Knight: a leap of two forward and one to the side, to either of two squares, jumping anything in between. Forward only — no sideways move, no way back.
• Lance: any distance straight forward along its file, not jumping.
• Pawn: one square straight forward, capturing the same way.

A man captures by moving onto the enemy man’s square. You may not capture your own men, may not leave your king in check, and may not pass. There is no castling move and no capture in passing.

Hand and drops

A captured man changes sides. He goes to the capturer’s hand and may afterwards be dropped, in place of a move, onto any empty square, facing his new owner and unpromoted. A promoted man captured reverts: a dragon taken is a rook in hand.

Three restrictions apply. You may not drop a pawn onto a file where you already have an unpromoted pawn — nifu; a promoted pawn of yours on that file does not count. You may not drop a man where he could never move again, which bars a pawn or a lance on the last rank and a knight on either of the last two. And you may not deliver checkmate with a dropped pawn — uchifuzume. A dropped pawn may give check; it simply may not be the mating move.

Promotion

The far three ranks are the promotion zone: ranks a, b and c for sente, ranks g, h and i for gote. Promotion is offered on any move that enters the zone, moves within it, or leaves it, and it is your choice. It becomes compulsory only when the man would otherwise have no legal move from where he lands.

Pawn, lance, knight and silver all promote to a man that moves exactly like a gold. The rook promotes to a dragon: rook’s lines plus one square diagonally. The bishop promotes to a horse: bishop’s diagonals plus one square orthogonally. Gold and king do not promote. A man dropped into the zone does not promote on arrival.

Winning, drawing and impasse

Checkmate wins. A player with no legal move loses; there is no stalemate draw. In practice most games end in resignation, because a lost position stays lost when captured men keep coming back.

Sennichite: a position repeated four times, with the same men on the board, the same men in both hands and the same side to move, is drawn — unless one side gave check on every move of the cycle, in which case that side loses.

Jishogi: if both kings have entered the enemy camp and neither can be mated, the game is scored. Rook and bishop count five each, promoted or not; every other man counts one; kings are not counted; men in hand count as if on the board. A side below twenty-four points loses, and if both reach twenty-four the game is drawn. There is no fifty-move rule.

Sources

Everything on this page is written from scratch. These are the works it leans on, and what each one settles.

• Nihon Shogi Renmei (Japan Shogi Association) tournament rules

  The rule set this variant implements, point for point: the scope of optional and compulsory promotion, the three drop restrictions, repetition with and without perpetual check, and the twenty-four point impasse count.