Is it illegal to play mahjong in the chess room?

It is not illegal to play mahjong in the chess room.

According to the laws of China, mahjong is a traditional recreational activity. Playing mahjong itself is not illegal as long as it does not involve illegal activities such as gambling. According to People's Republic of China (PRC) Public Security Administration Punishment Law, only gambling activities in public places will be punished by law. As an entertainment place, chess room only provides mahjong games for people to entertain, and does not involve gambling, so it is not illegal to play mahjong in chess room.