This paper gives an overview of the didactic elements relevant to foster learning in virtual worlds. The specific requirements of learning in virtual worlds are investigated in detail using the C3-model of didactic components. Following this model, the specifications of virtual worlds are illustrated with regard to the components “content”, “communication” and “construction”. The use of virtual worlds is often connected with the hope for stronger immersion, which is encouraged by the possibility of three-dimensionality and the representation of the learner by a virtual representative (“avatars”). However, learning-/teaching processes are not automatically improved by the use of virtual worlds. The possibilities offered by virtual worlds can only be honoured when a dedicated didactical concept is implemented. This means a complex composition process which has to take into consideration the specific features of virtual worlds.