Reversi (Othello)

Rules: players take turns placing discs on an 8x8 board. A move must bracket at least one line of your opponent's discs between the new disc and another of yours - all bracketed discs get flipped to your color. If you have no legal move, your turn is skipped. The game ends when neither player can move; whoever has more discs wins. Legal moves are highlighted with small circles. See Reversi on Wikipedia.