To set up different games, simply re-arrange the blocks in the game set. The big square block is always placed in the upper left hand corner; the other 11 blocks can be arranged around the big square block in 12 different ways. Then, you simply slide the big square from the upper left to the lower right without lifting, turning or removing any of the other blocks! The easiest puzzle requires 43 moves, the most difficult 263! What a way to encourage creative thinking and problem solving, while developing spatial relations skills! Listed in 1999 Games 100. Solutions available by mail. Handcrafted oak game set with 12 hardwood oak blocks measures 7-3/4"x9". For 1 player.