This abstract strategy game has sold over one million units worldwide, recognized for its straightforward yet challenging gameplay. Players take turns placing pieces to form a line of four sharing any single attribute—height, color, shape, or solidity. The unique twist requires opponents to select which piece you place each turn, adding strategic depth. The set includes solid wooden components with a natural finish, designed for durability and display. It received the Mensa Select award for its educational value and craftsmanship.