High Quality Content by WIKIPEDIA articles! Capricon is an annual, four-day-long (Thursday through Sunday) science fiction convention in a suburb of Chicago, which draws approximately 900+ people. Capricon attendees share an interest in science , science fiction, fantasy, and related genres. The Capricon convention has been held each year since 1981. Capricon is the annual gathering for Phandemonium, a not-for-profit organization, and is entirely volunteer run. The purpose of Phandemonium is to promote Science Fiction as a literary genre and to promote the Chicago area sf community.