Das F-Prinzip is an architectural 3 D board game which encourages a playful examination of the letter F. This concept is based on a constellation of four equally formed F-shapes modelled on the walls of a rectangular room. The short lower bar of the F may serve as a partition. Purpose of the game is to explore the manifold, sheer endless possibilities of creating floor plans and three-dimensional constructions. As a connector between language, shape and function, Das F-Prinzip enhances spatial thinking.