Xiangqi under Asian Xiangqi Federation rules

What this preset is

This is ordinary xiangqi played to the rules of the Asian Xiangqi Federation, the code used for international play. Nothing about the board or the pieces is unusual: nine files by ten ranks of intersections, a river across the middle, a three by three palace at each end, sixteen pieces a side, red to move first.

The one thing worth reading carefully is how repeated positions are judged. That section is below and it is the only place this preset differs from the casual one.

The pieces

General

One point orthogonally, never leaving the palace. The two generals may never stand on the same file with nothing between them, and any move that would create that position is illegal.

Advisor

One point diagonally, never leaving the palace.

Elephant

Exactly two points diagonally, blocked if the midpoint is occupied, and never across the river.

Horse

One point orthogonally then one diagonally outward, blocked if the orthogonal point it passes through is occupied by any piece.

Chariot

Any distance along a rank or file, through empty points, capturing the first enemy piece in its path.

Cannon

Moves like a chariot over empty points. Captures only by jumping exactly one intervening piece of either colour, the screen, and taking the first enemy piece beyond it.

Soldier

One point forward. After crossing the river, also one point sideways. Never backward, never diagonally, never promoted.

Repetition: perpetual check and perpetual chase

A player who is losing has an obvious temptation: find a sequence that forces the opponent to answer the same way over and over, and repeat it forever. In many games that earns a draw. Under federation rules it does not. The player doing the forcing is the one required to change.

Perpetual check is the simple case. If one player checks the enemy general repeatedly, driving the same position back again and again, that player must vary the moves. If the checking side will not stop, the game is scored as a loss for the side giving the checks. The reasoning is that a check is a threat the opponent has no choice about answering, so an endless series of them removes the opponent’s ability to play at all. The player creating that situation is treated as the one responsible for it.

Perpetual chase is the harder case, and the one that gives xiangqi its reputation for intricate rules. A chase is a repeated threat to capture a particular enemy piece: not a check, but a threat the opponent must keep answering by moving the piece away. Done once, that is normal play. Done forever, purely to repeat the position, it is the same abuse as perpetual check wearing a disguise.

This preset enforces the clearest form of it. When one player, and only that player, repeatedly chases an enemy piece that has no defender, the chaser must break off. If the chaser keeps going, the chaser loses. Two conditions matter and both must hold. The chase must be one-sided: if both players are chasing each other, neither is at fault and the repetition is simply a draw. And the piece chased must be undefended, because chasing a piece that is protected is not a genuine threat to win material and so is not a threat the opponent is compelled to answer.

The full federation code covers more cases than these two, and a human referee applies it with judgement. This preset implements the two that decide almost every real game: perpetual check, and the one-sided chase of an undefended piece. Any other repeated position is handled by the no-progress limit below.

Winning

• Checkmate. The enemy general is attacked and there is no legal move that ends the attack.
• Stalemate. The opponent has no legal move at all, in check or not. This is a win for you, not a draw.
• Perpetual check. Your opponent checks endlessly rather than varying, and loses for it.
• Perpetual chase. Your opponent repeatedly chases an undefended piece of yours, one-sidedly, and will not stop.
• Resignation, or your opponent’s clock running out in a timed game.

Drawing

• By agreement between the two players.
• By insufficient attacking material, when neither side can force a mate with what is left.
• By the no-progress limit: 120 half-moves, that is sixty moves each, with no capture at all.
• By a mutual repetition, where both sides are equally responsible, so that neither is judged the aggressor.

Note that plain threefold repetition is not itself a draw in this preset. A repeated position is examined to see whether one side is forcing it. If neither is, the game will run into the no-progress limit and be drawn there. If one side is, that side is penalised.

Sources

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

• Asian Xiangqi Federation, tournament rules

  The code this preset follows. It settles the two judgements described above: that perpetual check loses for the checker, and that a one-sided chase of an undefended piece loses for the chaser.