Jieqi rules

Jieqi is played on the familiar xiangqi board, but every piece except the General starts face down on its usual square. Nobody knows what a hidden piece is — not even its owner — until it moves.

Moving a hidden piece

• A hidden piece moves like the piece that normally stands on its square in xiangqi: a hidden piece in the corner moves like a Chariot, one on the soldiers' row like a Soldier…
• After it moves it turns over to its real piece (random among that side's 15) and moves as that piece from then on.
• Revealed advisors and elephants are no longer held back: the advisor leaves the palace, the elephant crosses the river, and both go anywhere on the board. They still move the same way: the advisor one step diagonally, the elephant two steps diagonally and still blocked at the eye. Only the general always stays in the palace.
• A captured hidden piece is turned over too, for both players to see.

Face-down pieces by square

• Board corner (Chariot square) — moves like a Chariot: straight along files and ranks, any distance.
• Horse square — moves like a Horse and can be blocked like one.
• Elephant square — moves like an elephant: two steps diagonally, blocked at the eye; while face down it cannot cross the river.
• Advisor square — can only step up to the centre of the palace; while face down it cannot leave the palace.
• Cannon square — moves like a Cannon and needs a screen to capture.
• Soldier row — only moves one step forward.

The most common mix-up: an advisor or elephant that looks stuck is still face down. Move it once so it flips; if it turns out to be an advisor or elephant, from then on it goes anywhere.

Tips for beginners

• The Chariot is the strongest piece, then the Cannon and the Horse: open pieces early to bring the strong ones into play.
• Opening a face-down piece on an Advisor square too early often turns up a Soldier that blocks the General — players usually open the Advisors last.
• The opponent's face-down pieces may be a Chariot or a Cannon too: don't leave a strong piece where one of theirs could capture it the moment it turns over.

Everything else as in xiangqi

• A turned-over Soldier that has crossed the river may move sideways, as in xiangqi.
• Check, checkmate, facing generals and having no legal move all lose.
• Threefold repetition or 60 moves without a capture is a draw; perpetual check or perpetual chase loses for the side doing it.
• Jieqi has its own Elo; jieqi games aren't reviewed by the engine because luck plays a part.