ខុន
KHUN · The king
One square in any direction — the chess king, minus castling. Once per game it may also leap; see 03.
Cambodian chess · since before the other one
Ouk Chaktrang
អុកចត្រង្គ
Cambodian chess, played on a phone. A descendant of chaturanga, older than the international game, still played across Cambodia today — and badly served by software. That is what this app is for.
Download on theApp StoreGet it onGoogle Play
Google Play Coming soon
- No account
needed - Khmer and
English - No ads, no
trackers - Plays
offline
ការលេង · How to play
Same board. Six characters you have not met.
If you play international chess you already know most of this. The three parts below are the ones that are actually different — and the ones the app follows Cambodian sources on, not engine convention.
01
How each piece moves
Six pieces
នាង
NEANG · The lady
One square diagonally, and that is all. There is no queen in this game — she is the weakest of the officers.
គោល
KOUL · The general
One square straight forward, or one square on any diagonal. Never sideways, never straight back.
សេះ
SEH · The horse
The chess knight, unchanged — the one piece that reads the same in both games.
ទូក
TUK · The boat
Straight lines, any distance, no jumping — the chess rook, and the strongest thing you own.
ត្រី
TREY · The fish
StepCapture
One step forward, captures diagonally. They start on rank 3, not rank 2 — that extra rank changes every opening.
02
The counting rule
ការរាប់A game that runs down to bare pieces is not left to peter out — it is settled by counting. 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. A winning position can slip away simply because you were slow.
First · ការរាប់ក្តារ
Counting the board
The ordinary case. 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.
Then · ការរាប់គ្រាប់
Counting the pieces
Once the counting side is down to its ខុន alone and no unturned ត្រី is left anywhere, the count starts instead from the number of men on the board plus one — and the limit comes from what the stronger side still has.
The limits · moves allowed
- ទូក ×28
- ទូក ×116
- គោល ×222
- សេះ ×232
- គោល ×144
The first line that matches is the one that applies; anything else is 64. Where sources disagree, the app follows the Cambodian statement of the rule.
03
First-move privileges
Not like chessOnce per game
The ខុន's one leap
The leapNormal step
From its home square the ខុន may jump once like a សេះ, 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.
First move only
នាង's two-square opening
The openingNormal step
On her first move only, the នាង may go two squares straight forward — the one time in the game she leaves the diagonal. It ends with the first capture too, so the two openings are really one decision.
Rank 6, not rank 8
ត្រី turns over
Rank 6
Reaching the sixth rank, the fish is flipped over — not replaced — and plays as a នាង for the rest of the game. It is still a ត្រី, and the rules book is emphatic about the two being told apart.
Also not here
No castling. No en passant. No queen. If a rule looks missing, it is missing on purpose.
អំពី · About the app
Built for the game, not for the store.
It works without an account
Playing the engine, solving the daily puzzle, keeping a streak, and using the board and clock all run on your device with no network and no sign-in. An account is only needed for online play, the leaderboard, a rating, and carrying your progress to another phone.
Khmer and English
The whole app is bilingual, and Khmer is not an afterthought bolted onto an English layout — it is set in a Khmer typeface throughout and never falls back to a Latin one.
No advertising trackers, no real-money gaming
There is no advertising SDK and no third-party analytics SDK in the app. The in-game coin (កាក់) has no monetary value, cannot be bought, cannot be cashed out, and cannot be wagered against another player. See the privacy policy for exactly what is collected and why.
Where the rules are disputed
Where the rules are disputed, this app follows Cambodian sources over the engine conventions used by international chess software. Where a Cambodian statement of a rule and a computer implementation disagree, the Cambodian one wins.
Who makes it
Ouk Chaktrang is built and published by Yean Seyha. For anything at all — a bug, a rules disagreement, a deletion request — write to support@yeanseyha.dev.