Tromino Go (1969)

Tromino Go is played using two differently-colored sets of 15 trominoes, which are all three squares in an "L" shape. The trominoes are lettered A, B, and C. After the first four trominoes are played using a different set of rules, players have to play in the letter sequence (A, B, C, then back to A), and also play so that no trominoes with the same letter touch each other. When a piece is played it must touch at least one piece of the other color and must have at least two squares touching other pieces. The object is to completely surround one or more opposing pieces with your pieces and/or surrounded empty space. If all pieces are played without this happening players move pieces on the edge of the playing area using the same rules. If players play a series of games, the winner of a game scores a point each surrounded piece.