Ouk Chaktrong || Four techniques to kill your opponent || Cambodian Chess

Ouk-Khmer (also known as Cambodian Chess) is a chess variant which D. B. Pritchard claimed was played in Cambodia although its actual origins appear to be unknown. It combines elements of makruk and xiangqi. Similar to xiangqi, it is played on the intersections of an 8×8 monotone board (Instead of 8x9). Contrary to Pritchard's claim, the actual variety of chess played in Cambodia today, known as "Ok" or "Ouk Chatrang" is nearly identical to Makruk.
The movement of the pieces as below:
Boat: Analogous to the rook in Western chess, the boat slides any number of spaces in the orthogonal directions (i.e. left, right, up, down).
King: As in Western chess, the king steps one space in any direction.
Horse: As with the knight in Western chess, the horse leaps one orthogonal and then one diagonal in any direction.
Elephant: The elephant moves as a king but cannot capture in the three backward directions.
Official: Like the queen, the official steps one space diagonally but can only capture in the two forward directions.
Fish: Analogous to the pawn in Western chess, the fish steps one space orthogonally forwards until crossing the center line of the board, at which point it promotes and may move as a king. And "the Fishes are irregular disks marked differently on either side so pieces which have crossed the center line and have been flipped can be distinguished."