Minishogi

The board and set-up

Five files by five ranks. Files are numbered 1 to 5 from sente’s right, ranks lettered a to e running away from sente, so rank e is sente’s back rank and rank a is gote’s.

Each side has six men: a king, a rook, a bishop, a gold general, a silver general and one pawn. Sente sets up along his back rank with the king on 5e, the gold on 4e, the silver on 3e, the bishop on 2e and the rook on 1e, and his single pawn on 5d, directly in front of the king. Gote’s array is the same shape rotated: king on 1a, gold on 2a, silver on 3a, bishop on 4a, rook on 5a, and his pawn on 1b, in front of his own king. Sente moves first.

How the men move

• 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, or one square diagonally forward. Never diagonally backwards.
• Silver: one square straight forward, or one square on any of the four diagonals.
• Pawn: one square straight forward, capturing the same way.

There are no knights and no lances in minishogi, so the two most awkward pieces of the full game are absent and the whole board is reachable by everything except the pawn.

Hand and drops

This is unchanged, and it is the reason minishogi is a real game rather than a toy. A captured man joins the capturer’s hand and changes side. In place of a move, you may drop a man from hand onto any empty square, unpromoted, facing you.

The restrictions are the full game’s. You may not drop a pawn onto a file that already holds one of your own unpromoted pawns — nifu, which since each side starts with a single pawn only bites once you have captured one. You may not drop a man where he could never move again, which here means a pawn on the furthest rank. And you may not deliver checkmate by dropping a pawn — uchifuzume; check is fine, mate is not.

On twenty-five squares a piece in hand is worth even more than usual, because there is nowhere on the board that is far from the enemy king. A rook in hand is very often mate in two.

Promotion

The promotion zone is the far rank alone — rank a for sente, rank e for gote. A move that enters that rank, moves along it, or leaves it may promote. Promotion is your choice, except that a pawn arriving on the last rank must promote, since it could not otherwise move again.

Pawn and silver promote to a gold’s move; the pawn becomes a tokin. The rook promotes to a dragon, adding one diagonal step to its lines. The bishop promotes to a horse, adding one orthogonal step to its diagonals. Gold and king do not promote. A man dropped onto the last rank does not promote by arriving — and a pawn may not be dropped there at all.

A one-rank zone is a real constraint. On the big board a rook that reaches the third rank from the end is already promoted; here it has to touch the very last rank. Getting a big man in and out of that rank safely is much of the middlegame.

Winning and drawing

Checkmate wins. A player with no legal move loses; there is no stalemate draw. Resignation is normal once mate is forced.

Sennichite applies on the fourth repetition: the same position, the same men in both hands and the same side to move, occurring four times, is a draw — except that a side which gave check on every move of the cycle loses. Perpetual check is no more an escape here than in the full game.

The twenty-four point impasse count of the big game can never decide anything here. A whole minishogi army — a rook and a bishop at five each, a gold, a silver and a pawn at one each — comes to thirteen points, so neither side could ever reach twenty-four, and the small-board rules say nothing further about impasse. In practice games on this board end by mate, by resignation or, rarely, by repetition.

Sources

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

• Japan Shogi Association small-board rules for minishogi

  The rule set this variant implements: a five-by-five board with king, rook, bishop, gold, silver and pawn a side, a promotion zone one rank deep, the full game’s drop restrictions including nifu and uchifuzume, and sennichite decided on the fourth repetition.