Plank is a public domain game that was included by Sid Sackson in A Gamut of Games. Players take turns laying "planks" and placing or moving markers on the resulting game board. Each plank has one red, one white and one blue field, which can only be occupied by markers of matching colors. The object of the game is to form a vertical or horizontal line of three markers, as in Tic-Tac-Toe.