How to Play
Learn the rules and pieces of Ouk Chaktrang — Cambodian chess.
🏛️ What is Ouk Chaktrang?
អុកចត្រង្គ (Ouk Chaktrang) is the traditional chess of Cambodia, played for over a thousand years. It shares common roots with international chess but has its own distinct pieces, moves, and character. Two players compete on an 8×8 board, each commanding 16 pieces, with the goal of trapping the opponent's King.
🎯 Objective
Your goal is to checkmate the opponent's ស្ដេច (Sdech — King). A King is in check when it is under attack, and in checkmate when it is in check with no legal escape.
🧩 The Pieces
Each side has 16 pieces: 1 Sdech · 1 Met · 2 Tuuks · 2 Kouls · 2 Ses · 8 Trey. Ivory = White · Dark = Black.
ស្ដេច Sdech (King) ×1
One square in any direction — orthogonally or diagonally. Cannot move into check.
⚠ No castling. Losing the Sdech means losing the game.
មេត្រី Met (Minister) ×1
Exactly one square diagonally in any direction. Very short range — the weakest piece.
⚠ Promoted Treys also become Met, so you can have several in one game.
ទូក Tuuk (Boat / Rook) ×2
Slides any number of squares horizontally or vertically. Blocked by any piece in its path. Same as the international chess Rook.
គោល Koul (Bishop) ×2
One square diagonally in any direction, OR one square straight forward. A short-range diagonal piece with an extra forward step.
⚠ The forward step gives it slightly more range than a pure Bishop.
សេះ Ses (Horse / Knight) ×2
L-shape: two squares in one direction then one perpendicular — identical to the international chess Knight. Jumps over all other pieces.
⚠ The only piece that can leap over others!
ត្រី Trey (Fish / Pawn) ×8
Moves one square forward. Captures one square diagonally forward. No double-push. Promotes to Met upon reaching the last two ranks of the opponent's side.
📋 Starting Position
White on ranks 1–2 · Black on ranks 7–8.
| # | a | b | c | d | e | f | g | h |
|---|---|---|---|---|---|---|---|---|
| 8 | ||||||||
| 7 | ||||||||
| 2 | ||||||||
| 1 |
Sdech on e · Met on d · Tuuks on corners · Kouls next · Ses innermost
📜 Special Rules
- ♟
Trey Promotion
When a ត្រី reaches the last two ranks of the opponent's side (ranks 7–8 for White · ranks 1–2 for Black), it automatically becomes a មេត្រី (Met). Unlike international chess, you cannot promote to any other piece type.
- 🚫
No Castling
There is no castling in Ouk Chaktrang. The Sdech must move on its own.
- 🚫
No Double Pawn Push · No En Passant
Trey always moves exactly one square forward. There is no two-square opening push and therefore no en passant capture.
- ⏱
Clocks
Every game uses a time control (Bullet · Blitz · Rapid · Classical). Running out of time is an immediate loss. If increment is set, it is added to your clock after each move you complete.
🎮 How to Play Online
- 1
From the Home page tap Play Now (vs a real player) or Play vs AI. Pick a time control and tap Find Game or Start Game.
- 2
White always moves first. Your pieces are at the bottom of the board; the opponent's are at the top. The board flips when you play Black.
- 3
Tap or click one of your pieces to select it. Legal destination squares light up with a dot (empty square) or a ring (capturable enemy piece).
- 4
Tap or click a highlighted square to move your piece there. Tap the selected piece again to deselect without moving.
- 5
Once you move, the opponent's clock starts. Watch both clocks — running out of time is an immediate loss.
- 6
If your Sdech is in check you must get it out of check immediately. You cannot make any other move.
- 7
The game ends on checkmate, timeout, resignation, stalemate (draw), 50-move rule (draw), threefold repetition (draw), or mutual draw agreement via the Controls panel.