What is Banqi?
Banqi, also called dark chess or half chess, is a game of chance and memory played with xiangqi pieces. All 32 pieces are shuffled and laid face down on the squares of a 4 by 8 board, half the size of a xiangqi board. Nobody knows where anything is.
On your turn you either turn a face-down piece over or move one of your own face-up pieces one square up, down, left or right. The very first piece turned over decides the colours: the player who flipped it plays that colour for the rest of the game. A piece you turn over may belong to your opponent, so every flip can help either side.
Captures follow a rank order instead of the xiangqi moves. A piece takes an enemy piece of equal or lower rank by stepping onto it, with two exceptions: the general can't take a soldier, and a soldier can take the general. The cannon is the odd one out: it captures only by jumping over exactly one piece, at any distance along a line. You win by capturing every enemy piece or leaving your opponent with no legal turn.
Rule changes
| Rule | Standard Xiangqi | Banqi |
|---|---|---|
| Board | Standard XiangqiThe full board: 9 by 10 points, with a river and two palaces. | BanqiHalf a board: 4 rows of 8 squares. Pieces stand on the squares, and there is no river or palace. |
| Starting position | Standard XiangqiBoth armies stand face up on their fixed starting points. | BanqiAll 32 pieces of both colours are shuffled and placed face down, one on every square. |
| Colours | Standard XiangqiRed and Black are chosen before the game, and Red moves first. | BanqiThe first player turns a piece over and plays its colour from then on; the other player takes the other colour. Turns simply alternate after that. |
| A turn | Standard XiangqiMove one of your pieces. | BanqiEither turn any face-down piece face up, whichever colour it turns out to be, or move one of your face-up pieces. |
| Moving | Standard XiangqiEach piece has its own move: chariots slide, horses leap, elephants and advisors move diagonally, and so on. | BanqiEvery piece, the cannon included, moves one square up, down, left or right onto an empty square. |
| Capturing | Standard XiangqiAny piece may capture any enemy piece it can reach. | BanqiA piece captures by stepping onto a face-up enemy piece of equal or lower rank. From high to low: general, advisor, elephant, chariot, horse, soldier. The general can't take a soldier, but a soldier can take the general. Face-down pieces can't be captured. |
| The cannon | Standard XiangqiMoves like a chariot and captures by jumping exactly one piece. | BanqiSteps one square like the others, and captures only by jumping exactly one piece, face up or face down, along a row or column at any distance. It can take any face-up enemy piece that way. Every piece except a soldier can take a cannon. |
| How to win | Standard XiangqiCheckmate the opposing general, or leave the opponent without a legal move. | BanqiCapture all of your opponent's pieces, or leave them with no legal turn. There is no check: the general is just the highest-ranked piece. |
| Draws | Standard XiangqiA position repeated a third time ends the game: a side keeping up a perpetual check or chase loses, otherwise it is a draw. | BanqiA position repeated a third time is a draw. So are 180 turns in a row without a flip or a capture; the result says which rule ended the game. |
History
Banqi takes its name, bànqí or half chess, from its board, which is half of a xiangqi board. It is also known as ànqí, dark chess, or blind chess, because the pieces start hidden. It needs nothing but an ordinary xiangqi set and is mostly played socially, for fun rather than in serious competition.
There is no single rulebook. The Taiwanese, Hong Kong and mainland Chinese versions rank the pieces differently or treat the cannon differently, and some house rules allow several captures in one turn. This table follows the Taiwanese version. Programs play the game under the name Chinese dark chess at the Computer Olympiad, and the two draw rules used here, threefold repetition and 180 turns without a flip or a capture, come from those tournaments.