In most of the country lighting a cigarette in public is getting harder and harder especially in California where I am from. In Las Vegas if you are a smoker you can do it just about anywhere even in a restaurant where they have smoking and non smoking sections. You can smoke in the casinos although a some have non smoking sections which are usually small and in the back of the casinos. One of the few places you cannot smoke in public is at the airport except in designated areas which are usually glass boxes in the terminals. I don’t smoke and have never really been bothered by it in Las Vegas, but if it does bother you i might suggest the larger casinos on the strip that have high ceilings and good air conditioning. Older casinos and downtown casinos generally have lower ceilings so I wouldn’t suggest them if you are sensitive to smoke. Most hotels offer non smoking rooms and will give you that option when you book, if not ask.