This article deals with some methodological issues regarding the relationship between medium (more specifically the question of transmediality) and use (more specifically the issue of interactivity) in the field of the fantastic. More specifically, it discusses some fundamental hypotheses on the way the interactive dimension of transmedial adaptations can either increase or diminish the fantastic effect. A special emphasis will be put on issues of time and narrative, on the one hand, and context and medium traditions, on the other hand.