Quoted:
Unless the casino has a sign or plaque( the casinos in Reno have plaques, at least Eldorado, Silver Lagacy, and Atlantis do on all of the entrances I have ever been through) that states firearms prohibited.There not the easiest to find either.
As seen in post up above:
"A public building that has a sign posted at each public entrance indicating that no firearms are allowed in the building."
You are mixing up the two....
A public building is a government building (owned by the public). A casino is a private building. The casino can post whatever they want... but a violation of their house rules will likely result in being asked to leave and would be an extremely far stretch to even get a trespass charge. Now, once they ask you to leave, refusing or returning at a later time will be a Trespass issue.