In their 34-page opinion, the justices found in favor of civil actions against violators of the ban, but ruled that that Clark County District Judge Doug Herndon properly found criminal enforcement unconstitutional. They rejected arguments from the state attorney general's office appealing that finding.
Several Las Vegas businesses appealed civil penalty, which call for fines of up to $100, arguing the law violates equal protection guarantees because it exempts gambling areas in large casinos—those with nonrestricted gaming licenses—as well as stand-along taverns and strip clubs.
They argued "no rational reason exists" to allow smoking in one place but not another based solely on what type of gaming license the business holds.
A five-member majority rejected those arguments, saying the exemptions are proper because minors are prohibited from gambling areas in large casinos.
Justice Michael Cherry agreed that criminal provisions were unconstitutional, but dissented with the majority, saying exemptions for big casinos make it unconstitutional.
Justice Ron Parraguirre recused himself from the case.
Nonrestricted license holders can have 16 or more slot machines and table games. Restricted licenses holders are limited to 15 or fewer slot machines.
The court said gambling is the "primary business" of nonrestricted properties, and that their other operations and services—such as restaurants where the ban is enforceable—are "incidental" to gambling.
"Restricted gaming licenses, however, offer gaming only incidentally to their other primary business, which makes it much more difficult, if not impossible, to provide an exclusion from the smoking ban for the gaming areas," Chief Justice James Hardesty wrote for the majority.
Justices Michael Douglas, Nancy Saitta and Kris Pickering concurred, as did Mark Gibbons, who in a separate statement said the ruling doesn't preclude anyone from challenging the law given specific circumstances.
"I make no conclusion as to whether the (statute) provides sufficient guidance as to what an aggrieved party's obligation is in the event a patron chooses to smoke in the aggrieved party's establishment," Gibbons said.
In his dissent, Cherry said the majority's reasoning for allowing smoking in casino areas but not others businesses "misses the mark."
The majority, he said, "ignores the reality that the dangers of secondhand smoke are the same whether the smoking is in a nonrestricted or restricted gaming licensee's business."
"To me, the exclusion for nonrestricted licensees that allows smoking only in the gaming areas is spurious at best, as the secondhand smoke is not confined within those boundaries merely because the actual smoking occurs only there."
The court also rejected the Nevada Tavern Owners Association's arguments that the ban constituted an illegal "taking of property"—indoor airspace—and that requiring the posting of no smoking signs was an invasion of property.