This game is one of a series of 2 player strategy games by Lakeside from the 1970's, also including Blockade, Trespass, and Isolation. In Overboard, the 'Slide to Survive' game, the board is a 7x7 grid of squares with slots between them to create a grid of 6x6 or 36 playing positions. There are 36 pieces, 18 red, 18 white, which are placed on the intersections between the squares they have little knobs which hold them in the slots. On his turn, a player uses one of his pieces to push a row of his opponent's pieces off the board, a la Kuba. The winner is the last player with pieces on the board. - BoardGameGeek