BEIJING— Tencent Holdings Ltd. says it will verify the identities of all its videogame players to sharply restrict online play time for youths in China, including limiting children 12 and under to one hour of play daily.

A verification system will check players’ identities and ages against police databases, and will be in place for 10 mobile games by the end of this year, Shenzhen-based Tencent said Monday. It plans to expand the system to all titles by 2019.

The restrictions are the most comprehensive play limits ever imposed here, and come as China’s authoritarian government tightens its oversight of videogames, which have been attacked by state media for their addictive quality and sometimes violent content.

“This action is pioneering—to do the ID verification,” said Chenyu Cui, a senior research analyst at IHS Markit.

China has more than 600 million gamers and Tencent’s verification system could involve checking hundreds of millions of people.