There is a list of things you are not allowed to do without a license if there is money involved. The problem is the grey area of whether the entry fee for the con and for the game is counted to mean that there is money involved.
No, none of the participants get any of the money, but that's beside the point. The entry fee could still count, and that's the grey area, an area that won't be properly classified until there is a court case most likely and we'd rather Conquest wasn't the first court case.
There exists the possibility that it might be all properly legal if we drop all prizes from the event in total, including both trophies and certificates. Jim and Liz are currently talking to people from the relevant department at the moment, and they'll let us know once they know.