(Pardon me for pretty much repeating something I posted in the Fans of GenCon FB group - is there some policy, written or otherwise, about that?)
I see in the Policies & Show Information page, under "On-site Badge Registration," it says:
"On-site Badge Registration will not be available at Gen Con 2018 this year. For additional information about the various badge types and associated costs, please visit the Badge Registration kiosks onsite or check out our Registration page."
I read this as, badges must be purchased online; nobody can walk into the Convention Center, put down their money (or credit card info), and get a badge on the spot. Of course, nothing (other than all of the badges being sold out) stops someone from ordering one online during GenCon, except that I think it takes 24 hours for them to be processed.
However, if this is true, then why does it mention "Badge Registration kiosks"?