Stacker is an "Amusement with prizes" (AWP) style game manufactured by LAI Games. The aim is to align rows of moving blocks on top of each other by pressing a button, when a player gets to the top row he/she/it wins a prize. There is also a "minor prize" which costs significantly less than the price per play; the sole purpose of this is to get people addicted to playing the game and give the impression that it is possible to win a major prize; however it can be very hard, and according to an operator's manual for the game, the approximate win per play ratio can be set as high as 1 in 800.