Chess.com - 4 Player Chess

"A long time ago in a kingdom far, far away… In Chessdom realm, the old king died and forgot to say who will be the new ruler of Chessdom. He had four sons: Red, Blue, Yellow, and Green prince, who were challenging for the throne after the death of their old king. They gathered their armies of chess pieces and went to the battlefield of chessboard. And their battle began..."