Desdemona

Black and White alternate putting disks on empty squares from an initial opening position. Each disk must be placed so that it sandwiches one or more enemy disks between itself and another friendly disk, with no empty squares in-between.

The sandwiched enemy disks are flipped, changing color:

+ When a player flips an enemy stone, it becomes gray. If a player flips a gray stone, it becomes one of his own stones.
If one player can't move, he must pass his turn.

The game ends when neither side can move. The winner is the player with most pieces of his color. Gray disks are not accounted.

—description from the designer