In Blokus, players (up to 4 players in a game) take turns placing their playing pieces (tetris pieces, pentominoes, and other shapes) on the board. The rules are simple; you have to place your piece so it touches another of your pieces on a corner only. Your goal is to lay as many pieces as you can, and at the same time, block your opponents from playing their own pieces. If you play carefully and cleverly, you can trap your opponents with your playing pieces and prevent them from playing theirs.