The game consists of 12 different pieces constructed of right angled blocks so each piece is made of 5 "squares". (Think Tetris pieces, but 5 squares instead of 4.)
An old version of the game had only 10 pieces; the completely straight 5 square and the 5 square "plus sign" were not included. Both versions also have a bunch of "filler" pieces of 1 or 2 squares.
The gameboard is constructed with a movable divider so one can take sets of 4 up to the whole set of 12 pieces and form them into a 5 block by X rectangle. (Where X = the number of wood blocks in your set.)
The two player puzzle game mode is accomplished by dividing the board into two sections, each player chooses five blocks and are also given 4 small "filler" blocks of 1 and 2 squares. The first one to fit all their blocks perfectly into their half of the rectangle board, wins.
