An expansion for Tixel, which consists of 2 extra pieces for each player that enables Poka Yoke to be played. Expansion pieces are different from regular pieces in that they have the shape of Regatta pieces, so besides being hollow on one side they also have one rounded corner. The Poka Yoke expansion pieces are used to add piece promotion to the Tixel base game. Whenever you do a pickup of one of your pieces, it is promoted to a Poka Yoke expansion piece (with a maximum of 2 promotions for each player per game). -description from designer