Which game is a chess variant, Ubongo or Ouk-Khmer?
Ouk-Khmer (Hill's version) 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. Pritchard gives the source as P. A. Hill. 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 authenticity of the game described by Pritchard remains doubtful.
Transcendental chess Transcendental chess is a chess variant invented in 1978 by Maxwell Lawrence. Chess960 (Fischer Random Chess) is similar but has fewer starting positions. In transcendental chess the beginning positions of the pieces on the back row are randomly determined, with the one restriction that the bishops be on opposite-colored squares. There are 8,294,400 such positions in total. In Chess960 there are 960 possible starting positions, but that is because the king must be located between the rooks and both sides must have the same starting position. In transcendental chess there is no such rule so the position of one side can be any of = 2880. There is no castling. On the first turn a player, instead of making a move, can transpose any of two pieces on the back row.