Khmer chess rules: how to play Ouk Chaktrang

01 · The six Cambodian chess pieces

Each side has sixteen men: one Khun, one Neang, two Koul, two Seh, two Tuk and eight Trey. The Trey start on the third rank, not the second. The diagrams show each piece's normal moves.

Khun — the king

ខុន

One square in any direction — the chess king, minus castling. Once per game it may also leap; see 03.

Neang — the lady

នាង

One square diagonally, and that is all. There is no queen in this game — she is the weakest of the officers.

Koul — the general

គោល

One square straight forward, or one square on any diagonal. Never sideways, never straight back.

Seh — the horse

សេះ

The chess knight, unchanged — the one piece that reads the same in both games.

Tuk — the boat

ទូក

Straight lines, any distance, no jumping — the chess rook, and the strongest thing you own.

Trey — the fish

ត្រី

StepCapture

One step forward, captures diagonally. They start on rank 3, not rank 2 — that extra rank changes every opening.

02 · The counting rule

Once a side is reduced to three men or fewer, that side may claim the count and says a number aloud on each of their own moves. If the limit is reached before checkmate, the game is a draw.

Counting the board

The counting side starts at one and has sixty-four moves. Reaching the number draws — the stronger side does not get a move at it.

Counting the pieces

Once the counting side has only its Khun and no unturned Trey remains anywhere, the count starts from the number of men on the board plus one. The limit comes from what the stronger side still has. Use the first matching row below.

03 · First-move privileges and promotion

The Khun's one leap

From its home square the Khun may jump once like a Seh, onto the next rank only, and never to capture. You lose the right the moment it has been checked — or the moment any piece is taken, by either player.

The Neang's two-square opening

On her first move only, the Neang may go two squares straight forward — the one time in the game she leaves the diagonal. It ends with the first capture too.

The Trey turns over on rank six

Reaching the sixth rank, the fish is flipped over and plays as a Neang for the rest of the game. It is still a Trey, and the two must be told apart.

Differences from international chess

There is no castling, no en passant and no queen. The Neang moves one square diagonally. The fish turn over on the sixth rank, and endgame counting can settle a game as a draw before checkmate.

Practise the rules in the app

Start against the Novice bot, or use the app's explanations of every piece and rule in Khmer and English. The six bots work offline without an account. To play Khmer chess online with a friend, create a free account, open a room and share its room code.

Download Ouk Chaktrang or read the Khmer chess app FAQ.