A perfect companion to our best-selling LEGO Crazy Action Contraptions, this all-new book will blow the mind of anyone who enjoyed playing Mouse Trap or setting off a row of dominoes. To turn bricks from kids' own LEGO collection into ball-moving machines, all they need is LEGO Chain Reactions- along with the cardstock ramps and other punch-out parts, plastic LEGO balls, and 33 essential, hard-to-find LEGO pieces packed inside.