"I can go to (South) Korea," Zhu said, while chain-smoking outside Melco Crown Entertainment Ltd's City of Dreams casino in Macao. "It's even closer to Shandong."

While Singapore is Macao's biggest regional rival, South Korea may develop as manyas nine gaming-integrated resorts. That would make it a prime destination for Chinese gamblers after Macao, according to Bloomberg Intelligence analysts Margaret Huang and Tim Craighead.

South Korea does not allow smoking in the casino that only locals are authorized to attend, but permits smoking lounges. For the 16 casinos reserved exclusively for foreigners in the country, there are no smoking rules although some have voluntarily designated non-smoking areas, according to DS Kim, an analyst at JPMorgan Chase & Co.

Studies have shown smoking rates among casino-goers tend to match the broader population. That implies that in China, where there are more than 300 million smokers, at least one in every two male gamblers is likely to smoke－a clientele governments with even the strictest anti-tobacco laws are more willing to accommodate.

The Las Vegas Sands Corp-owned Marina Bay Sands casino, located at the base of an iconic building featuring the world's largest rooftop pool, allows smoking in specified areas.

These include private gaming salons, but not in hallways or on one of its levels designated as a non-smoking floor. On Singapore's Sentosa Island, the Resorts World casino, allows customers to light up in designated smoking areas.

Smoking rules in casinos in Australia, which pioneered laws requiring graphic warnings and plain cigarette packaging, vary across states. Only international VIP players are allowed to smoke in private gaming rooms at Echo Entertainment Group Ltd's casino in Sydney, while domestic high-rollers are also allowed to light up in its Queensland resorts' VIP rooms.

Philippine casinos, such as Bloomberry Resorts Corp's Solaire Manila, which opened in 2013, allows smoking in most areas, with smaller zones set aside for non-smokers.

China's government may not be as accommodating. Beijing's public smoking ban was applied to all indoor areas in June, an initiative that other cities may replicate, said Angela Pratt, who leads the World Health Organization's tobacco-control efforts in the country. The central government is canvassing public opinion on a proposal to ban indoor-smoking nationwide.