Authorities are threatening gamblers with jail time for holding "high stakes" games during the Chinese New Year, a time when mahjong marathons with family is a holiday tradition.
According to China's Public Security Administration Punishments Law, those caught playing for high stakes face between a 10- to 15-day stint in jail and fined up to 3,000 yuan ($320), Nanjing Broadcast Company (NBC) reported on Wednesday.
The law does not state what is considered "high stakes."
Many Chinese were shocked by the news, as games of mahjong with family are common ways to pass the time during Spring Festival, the most important festival in China, which fell on January 28 this year.
But recent police busts may give a clue as to what is high stakes. Police in Longkaikou, Yunnan Province confiscated 20,000 yuan and detained 10 people Monday for gambling.
City governments in China have also set their own limits on what constitutes punishable gambling.
According to news site guancha.com, Shanghai put a 100-yuan cap on gambling while Sichuan Province defines high stakes as between 1,000 and 4,000 yuan.
But the law has seemingly not affected business in Macao, the nation's only haven for legal gambling.
Resorts Wynn Macau and Wynn Palace saw all of their 2,700 rooms booked for Spring Festival, reported casino.org, an international casino website.