When does Gen Con Online registration open? May 07, 2021 19:00 Registration for Gen Con Online will be open on June 27, 2021. Related articles Will 4-Day badges sell out for Gen Con Indy? When is Gen Con opening badge and event registration for 2021? If Gen Con Indy badges sell out, will more become available? How many badges will be available for Gen Con Indy 2021 badge registration? If I bought a single day badge and 4-Day badges become available, will I be able to convert it?