Really Bad Chess is an iOS game by Zach Gage that randomizes the distribution of pieces when the board is set up, so that you might start a game with 4 queens, 3 knights, and only 2 pawns in the back row. The result is that you get a completely new strategic game each time, but you still play with the familiar tactical rules of chess. What a great idea…I can’t tell if people who really love chess will love or hate this.
Update: See also Knightmare Chess:
Knightmare Chess is played with cards that change the default rules of chess. The cards might change how a piece moves, move opponent’s pieces, create special squares on the board or otherwise alter the game.
and Chess960 invented by Bobby Fischer:
It employs the same board and pieces as standard chess; however, the starting position of the pieces on the players’ home ranks is randomized. The random setup renders the prospect of obtaining an advantage through the memorization of opening lines impracticable, compelling players to rely on their talent and creativity.