Inspired by the traditional Chinese legend of Biyi (a one-winged bird), Biyi the game is an abstract strategy game for two players that combines the strategy of chess with the simplicity of checkers. It is unique in many ways, one of which being the fact that none of the playing pieces on the board are ever removed. Additionally, you must not only strategize in 2D, but also in 3D as you stack pieces atop one another in order to bypass your opponent's defenses. (boardgamegeek.com)