The game consists of a 3 x 3 wooden board, a rubber band and a stack of cards depicting positions of the rubber band (the 3 x 3 "fields" on the board are actually little poles over which the rubber band can be stretched). There are various game variants described in the rules. The basic mechanism is to execute one or two out of three permitted moves. To understand these it is important to note how many corners the pattern of the rubber band has (i.e. triangular, rectangular, etc.). The number of corners can be increased by one, decreased by one or stay the same, with one corner being moved to a new position. The player using least moves to reach the positions on his/her cards is the winner.