What is "chaturaji"

Chaturaji (meaning "four kings", and also known as choupat, IAST , ) is a four player chess-like game. It was first described in detail c. 1030 by Al-Biruni in his India book. Originally, this was a game of chance: the pieces to be moved were decided by rolling two dice. A diceless variant of the game was still played in India at the close of the 19th century.