The Hong Kong protests are being played out on Grand Theft Auto (GTA) V online.
Axar.az reports citing BBC.
Players in Hong Kong realised they could dress up as protesters after a new update for the game was released earlier this month.
They spread the word on LIHKG - which has been called the Hong Kong version of social news site Reddit - and started organising violent expeditions.
Mainland players responded by showing up dressed as riot police with water cannon trucks.
Hong Kong-based news site Abacus was one of the first to report the development.
The Hong Kong protests started in June over a controversial extradition bill, and have now evolved into broader anti-government demonstrations.
GTA V is set in the fictional city of Los Santos, which is based on Los Angeles.
But that has not stopped gamers in mainland China and Hong Kong from using it as a battleground.