18"x 18" x 1"
Ex Cross (or X+) is a prototype abstract strategy game. The following is an excerpt from Rosie Sharp's essay describing the game:
Players line up two-sided wooden game pieces, each embedded with the eponymous X on one side and + on the other, along the back row of a modified checkerboard. In three-movement turns, players navigate the board, trying to capture each other along diagonals for X and orthogonal for +. Each piece can, at any time in a turn, flip to alter its capacity to move. Malone used this game as an opportunity to discuss with his daughter, Julia, the opposing philosophies of Dr. Martin Luther King, Jr. and those of Malcolm X. As Malone sees it, each of these civil rights leaders was locked into a singular kind of movement, but ultimately an individual has better options when able to think flexibly.
Jump to 0:51 mark on video for Ex Cross Game Play