Nevada is an Open Carry state, so you can wear it holstered OWB. When you get to the casino, they will likely have a policy against carrying a firearm but it is not against the law. I have OC'd in the hard rock and it didn't take long before security approached me. They were polite and asked me to either put the gun in my car or hotel room if I was going to stay on the casino floor. That being said, you may not want to be inconvenienced if someone freaks out and calls metro pd for a "man with a gun" call.