HARRISBURG — A majority of states have banned smoking in most indoor places, but for the casino industry, this is an especially touchy subject. Casinos claim that an unusually high proportion of gamblers smoke, and in an increasingly competitive gambling industry, smokers have options.

Whether Pennsylvania bans smoking in most public places and workplaces — casinos included — appears headed toward acrimonious debate in the General Assembly this week. The struggle to pass the broadest ban will pit advocates for public health and lower insurance costs against business owners worried about a devastating hit to their bottom line.

Numerous amendments are being penned, including ones to excuse at least a portion of the gambling floors in Pennsylvania's slots parlors.

None of the five parlors has come out to support a smoking ban, and most are said by legislators to be lobbying for an exemption from bills that, as currently written, apply to everything from casinos to convention halls.

Some casino executives say people who like to gamble with a cigarette in hand will take their cash to casinos where smoking is allowed, like those in Atlantic City, N.J., New York and West Virginia.

That could put legislators in a Catch-22: A smoking ban may appeal to a majority of voters, but it could dampen the stream of state tax revenue from gambling that is expected to cut property taxes and pay for huge civic development projects.

"You can't have it both ways," said Sen. Vincent J. Fumo, D-Philadelphia.

A ban will be welcome in some quarters.

Charlotte Smyth, an avid gambler from Freeland in northeastern Pennsylvania who quit smoking two decades ago, is tired of breathing second-hand smoke while at the slots, and she's tired of smelling like smoke afterward.

Even the nonsmoking slots floor at Pocono Downs at Mohegan Sun, outside Wilkes-Barre, is no good, she said, because cigarette smoke creeps in from downstairs, where smoking is allowed.

A study released late last year challenges the casino industry's claims that the proportion of gamblers who smoke is much larger than that of general population. The study, by the University of Nevada, found that the percentage of gamblers in that state who smoke is similar to the rate for the overall population — about one in five.

One problem for commercial casinos may never go away: Indian casinos, a fast-growing industry, are not beholden to state smoking laws. Smoking is banned at the slots parlors at New York's racetracks, and track officials acknowledge they have a disadvantage compared with the state's expanding ranks of Indian casinos.

And at least in the short run, revenue figures from smoke-free casinos in Delaware and Ontario — both places with competition within a short driving distance — appear to underscore the hit that casinos will take from a smoking ban.