When I read some of the GenCon rules it said no weapons, which makes sense. It further went on to say their projecting police officers would not be allowed to have their firearms. Hope that is a joke, I don’t know a single cop who would work an event without a firearm, not to mention, there should be armed security.
It says off-duty
police, military, etc. are not allowed to bring firearms.
That sounds like the people who wrote the policy take for granted that on-duty security will be armed.
They also explicitly say that, while misleading uniforms are not allowed as costumes, active-duty military can wear their real uniforms.
You can find the policy under Attend > Attendess FAQ > Policies & Show Info
Weapons and items that appear to be weapons are not allowed at Gen Con. Self defense, recreational and utility items such as knifes, tasers, pepper spray, BB guns, cap guns, air-soft weapons, paintball guns, water guns, martial arts weaponry, including wooden practice weapons, etc., are not welcome, even if it is lawful to own and carry them in other public places. Off-duty security, law enforcement and military personnel are not allowed to bring their weapons to Gen Con. Items resembling futuristic weapons, fantasy weapons, and non-projectile boffer weapons may be allowed provided they are not handled in a careless, threatening, or destructive manner against persons or property.