This book constitutes the refereed proceedings of the First Joint International Conference on Interactive Digital Storytelling, ICIDS 2008, held in Erfurt, Germany, in November 2008.<BR>The 19 revised full papers, 5 revised short papers, and 5 poster papers presented together with 3 invited lectures and 8 demo papers were carefully reviewed and selected from 62 submission. The papers are organized in topical sections on future perspectives on interactive digital storytelling, interactive storytelling applications, virtual characters and agents, user experience and dramatic immersion, architectures for story generation, models for drama management and interacting with stories, as well as authoring and creation of interactive narrative.