The game has a plastic version of a cornucopia (horn) into which various objects are placed. There are 6 different objects: a wooden marble, a wooden cylinder, a wooden block, a bell, a metal marble and a piece of cloth. There is also a set of 40 cards which have photos of different mixes of the objects and also a '?' allowing for your own object.
4 cards are turned over and one player secretly chooses one of the cards and fills the horn with the objects shown in that picture. The horn is closed and the next player shakes it and tries to guess which card has been used by the sounds that are made.
The game is intended to develop the ability to pick out different sounds. The original 2001 prototype made by Reinhold Wittig (titled Das Füllhorn) had an African animal horn which was filled.