This article looks at the impact of video games on transmedia fantasy worlds using The Witcher as a primary example. While Hollywood-centred franchises tends to follow a “mothership” model of transmedia, with one dominant platform surrounded by ancillary texts, The Witcher demonstrates an alternate model in which the video game series plays just as central a role as the TV adaptation. The article introduces the concept of “dual industrial core” transmedia to describe this type of franchise and explains its implications for fantastic storyworlds. Whereas mothership transmedia attempts to offer high levels of completeness and consistency, particularly in relation to the storyworld’s mythos and topos, dual industrial core transmedia favours gr...