The principle: maps showing different stacks of 4 pieces of wood, the child tries to reproduce what he sees on the map (the red piece in blue, rabbit on the side ...) with 4 levels difficulties. This helps to master the notions of space in front, behind, in front, side, top, bottom ... My daughter started to play a little before two years, and within months she mastered green cards and now the oranges. She claims often to play there, and she is very proud when she arrives to replicate the model. Besides the rabbit is cute, she takes to play with her dolls. And even adults can play with the blue cards!