Children in China will only be able to play online games for three hours in a typical week - an hour a day on Fridays, Saturdays and Sundays, between 8pm and 9pm.
This lone gaming hour will also be allowed on public holidays, The National Press and Publication Administration announced (thanks, BBC News).
These new curbs are the latest steps in the Chinese state's battle against online gaming, which has been dubbed "spiritual opium" for the country's youth.
Online gaming companies will have to enforce these time limits within their games, and inspections of developers by the Chinese government will be stepped up.
Previous rules had let under 18's play online games for 90 minutes each day of the week (down from three hours per day before that), with up to three hours on holidays.
The Chinese government has enforced these limits by using real-name identification to log and track the online gaming habits of children, backed up by a police database.
In July, Tencent launched facial recognition technology which could determine exactly who was playing, to stop children logging in using their parents' IDs.
"Anyone who refuses or fails the face verification will be treated as a minor," Tencent said, "and as outlined in the anti-addiction supervision of Tencent's game health system, and kicked offline."