Dvonner is a great Windows game that features tough AI opponent for the game of Dvonn, a fun and unique tile-stacking abstract board game invented by Kris Burn in 2001.From the official site: "DVONN is a stacking game. It is played on an elongated hexagonal board, with 23 white, 23 black and 3 red DVONN-pieces. In the beginning the board is empty. The players first place the DVONN-pieces on the board and next their own pieces. Then they start stacking pieces on top of each other. A single piece may be moved 1 space in any direction, a stack of two pieces may be moved two spaces, etc. A stack must always be moved as a whole and a move must always end on top of another piece or stack. If pieces or stacks lose contact with the DVONN pieces, they must be removed from the board. The game ends when no more moves can be made. The players put the stacks they control on top of each other and the one with the highest stack is the winner. Just like GIPF, DVONN picks up the tradition again of just a board with pieces on it. No fuzz; the game in itself is tricky enough. The higher a stack, the more valuable it is, but the less mobile it is, too. With that in mind: watch out for the red DVONN-pieces: they may be moved! The outcome of a game of DVONN can completely change right up to the very last move." If you are a fan of Gipf for One, another cool abstract game reviewed elsewhere on this site, you will probably also enjoy this fanmade PC version of one of today's most interesting series of abstract board games. Two thumbs up!