How Tsume Shogi Works: The Rules and Conventions of Shogi Mate Problems

A tsume shogi (詰将棋) problem asks you to checkmate the lone enemy king. You play the attacker (Sente, the pieces pointing up the board) and must force mate. But tsume problems follow a few conventions that surprise newcomers — once you know them, the puzzles make sense.

Every attacking move must be a check

This is the defining rule: every move YOU make must give check (王手). There are no quiet preparing moves — if a move does not check the king, it cannot be part of the solution. So at each step you are looking only among checking moves for the one that leads to a forced mate.

The defender always plays the best defense

You do not control the defender (Gote, the king's side). The defender is assumed to play the move that escapes mate for as long as possible — the longest, best resistance. On TsumeDojo the defender's reply is played automatically. Your job is to find an attacking sequence that mates against the defender's BEST defense, not just against a careless one.

The defender holds all the remaining pieces

A common surprise: the defender's hand is often full of pieces (rooks, golds, pawns…). The convention is simple — every piece that is not on the board and not in the attacker's hand belongs to the defender's hand. That means the defender can drop a piece to block a distant check (an interposition, 合駒). Your mate has to work even against those drops, so always read whether the defender can interpose.

No pointless interpositions, and one unique mate

The defender will not throw in a pointless interposition (無駄合) that you simply capture with the mate unchanged — only meaningful defenses are played. And a well-made tsume has a single, unique shortest mating sequence (no alternate solutions, or 余詰). Every problem on TsumeDojo is verified by a solver to have exactly one shortest solution, so you can trust that there is one intended answer.

How to solve on TsumeDojo

Tap a piece (or a piece in your hand) and then tap its destination to play a checking move; the defender answers automatically. Keep checking until the king is mated. If you play a move that is not the intended one, the board shakes and rewinds so you can try again. Start with mate-in-1 to get the feel, then work up the move counts.