Ice Age Chess
In this game, empty squares (those not occupied by pieces) are filled with ice cubes. These ice cubes block the path of pieces until they are captured. However, every 20 moves, a new Ice Age refills empty squares with a whole new set of ice cubes! If the ice cubes completely surround a piece at this time, it is "frozen" and removed from the board (and replaced by none other than another ice cube). If a king is either frozen or checkmated, the game ends. If both kings freeze, it is a draw. This game brings a completely different way to strategize and emphasizes the value of time. Have fun!
Play it online: http://play.chessvariants.org/erf/IceAgeCh.html