Chaturanga for four players probably originated in India about 1000 years ago, and is believed to be a development of 2-handed Chaturanga. At least until the end of the 19th century, a variant of 4-handed Chaturanga was played in several parts of India. In medieval times, the game was mostly played with dice (four-sided long dice), often with stakes involved.

The four players form two teams of two players. Red plays together with yellow, and green plays together with black. The king, rook, and knight move as in orthodox chess. Pawns, too, move as in orthodox chess, but have no initial double move. The boat jumps two squares diagonally.

The first team that has taken both opponents' kings wins the game. The medieval long dice determine which piece can be moved. To throw the dice, click on the left die. One can make two moves in a row, or choose to pass one or both moves. To pass a move one must press the yellow marking on the right side of the board. A tone is then heard. The long die has four sides, showing 2, 3, 4, and 5. Its values are as follows: 2 = boat, 3 = knight, 4 = rook, 5 = king or pawn. You must pass manually if you don't own the piece anymore.

A player can not move his pieces after his own king is captured (the program will pass his moves automatically). However, should the partner capture an enemy king, then the immobilized party can re-introduce a king, and become mobile again. When this happens, a king appears to the right of the board. The immobilized player can introduce this king on an empty square anywhere on the board. In this case he has no second move, so he must pass the second move. Note that a king that has been captured twice cannot be introduced again.

Pawns promote to any of the four types: rook, knight, boat, or king. Piece-type is determined by the promotion square. For Yellow, the a-, and h-files are boat-files, as the boats' initial squares are on these files. Hence, Yellow promotes to boats on a8 and h8, knights on b8 and g8, rooks on c8 and f8, and kings on d8 and f8.

It is possible to capture one's partners pieces. However, in this implementation, capture of the partner's king is prohibited (that would be unethical!). The engine will in most cases avoid capturing his partner's pieces.