This introduction lays out the case for approaching special effects from a transmedia standpoint, focusing on the unexpected roles they play in building and maintaining the storyworlds of fantastic media franchises and redefining traditional notions of media authorship, performance, and genre. Relevant scholarship on spectacle, film technology and narrative, and transmedia storytelling is reviewed, with an emphasis on the gap between studies of special effects and convergence culture, which this book seeks to fill. An extended discussion of preproduction practices in early cinema and Classical Hollywood provides an alternative framework for understanding special effects as designed imagery. Previews of the book’s chapters conclude the introduction.