During the Passover seder, three pieces of matzah are used. As the fourth part of the Seder, the leader breaks the middle piece in half; the largest piece is set aside to be served as the afikomen (from the Greek word for dessert). In most houses, either the leader hides the afikomen and the kids have to find it, or the kids steal the afikomen and ransom it. In either case, the kids are given ‘gifts’ (often gelt, chocolate coins) for finding or returning it.
Until the afikomen is returned, the Seder cannot be concluded, as it’s the last thing to be eaten (after regular desserts even). This tradition, instituted in the Middle Ages, was devised to help keep the kids engaged and entertained during a long meal with a lot of interruptions for education. Read On