The feature was launched on Tuesday for over 60 games owned by Tencent, the biggest player in the mobile game industry in China. Dubbed “Midnight Patrol,” it will occasionally ask adult players playing at night to verify their identity through a facial scan. The verification database is linked with the central public security system.

The measure enforces a government ban on gaming between 10pm and 8am, which was introduced for minors in 2019, along with other restrictions. The prohibition was meant to curb gaming addiction among children, which, the authorities argue, leads to health problems like short-sightedness and to harmful behavior in kids, like stealing money to top their accounts, and to downward sliding in school grades.

Other rules capped microtransactions, both for single purchase and in total per month, and limited the time minors can spend gaming each day. The government said the instruction was directed both at the gaming industry and at legal guardians.

Some teen gamers did what teens in all countries do about adult rules that they don’t like: they started finding loopholes to get around the ban. One of the tricks is to register an account in an adult’s name and use it. Tencent’s ‘Midnight Patrol’ is aimed against this kind of shenanigan and will eventually expand to other products marketed by the company, it said. Adults kicked out of a game at night due to a false negative scan can simply take another identity verification.

The statement also announced that adults now have an option to lock parental control settings of accounts of kids in their custody, so that any change requires facial recognition. This is supposed to make it harder for underage gamers to swipe their parents’ phones and get more privileges.

Tencent’s gaming division is a dominant player in China, estimated to hold nearly 55% of the market last year, according to Sixth Tone, a Chinese online magazine aimed at Western audiences. Its flagship game ‘Honor of Kings’ has been the highest-grossing mobile game worldwide for two years straight, with domestic players accounting for a great chunk of the base.

The new rules come as the Chinese tech sector is struggling with skepticism among international investors amid Beijing’s increased regulatory attention. The antitrust watchdog SAMR issued 22 fines this week against leading Big Tech corporations in China, including Tencent, over merger irregularities.

Last week, the Cyberspace Administration of China (CAC) ordered the app of Didi Global to be removed from digital stores shortly after launching an investigation into its security. The regulator cited Didi’s violations in its collection and handling of personal information as the reason.