Given a polyomino with cells, two players and alternately color the cells of the square tessellation of the plane. In the case of -achievement, player tries to achieve a copy of in his color and player tries to prevent from achieving a copy of . The handicap number denotes the minimum number of cells such that a winning strategy exists for player . For all polyominoes that form a square of square cells, the handicap number will be determined to be .
Keywords: polyominoes, achievement game, handicap number