According to industry analyst Daniel Ahmad, whose company Niko Partners sometimes works with Tencent, “It will essentially detect if the person playing the game after midnight is doing so for a long time or spending a certain amount of money in the game, and it will tick a box in Tencent’s backend and prompt the user to verify their identity through facial recognition, either through that database or through a database they’ve already used.”
The company claims that they do not store the scans that they use. Instead, it sounds like it tries to match the gamer to China’s own state facial recognition system. Prior to this, Tencent has been verifying the age of users through China’s national ID system, but apparently some gamers have been crafty enough to get around the system by using their parents’ accounts.
For those concerned about privacy, it seems that users can opt not to have their faces scanned. For example, if a player is detected playing games after curfew, they will be prompted for a facial scan. They can refuse to do so if they wish, but then the system will simply assume they’re a minor and boot them off.