Fantasy and science fiction seem to be crucial genres for transmedia storytelling, with notable contemporary examples such as The Matrix, Star Wars, Doctor Who, Lost, and Heroes. What do fantasy and science fiction offer as a structural or thematic framework for constructing storyworlds that cross multiple media? If world building is a key concern of transmedia storytelling (Jenkins 2006), the nature of world creating in these genres is pivotal, and certainly much more evident than in crime, mystery stories, and even horror stories; in science fiction and fantasy, in fact, the creation of detailed settings seems to be a structural necessity.

My contribution focuses on science fiction writing from a semiotic and narratological point of view, with particular reference to studies on possible narrative worlds and on enunciation. First, I will briefly summarize some key aspects of the theory of possible worlds with regard to the science fiction genre; on this basis, I will tackle a definition of science fiction worlds before investigating more deeply their nature. Finally, I will explore the question of narrative transmission, both in regard to the first elements that allow access to the fictional world and, more generally, in relation to the enunciative modalities of the genre.