If you’re accustomed to the age rating of games in the US, it’s easy to forget that this is a voluntary system rather than an official one. The new rating that China is introducing, on the other hand, is very much a mandatory system. All games will be rated in one of three categories for players 8 and up, players 12 and up, and players 16 and up, with each rating associated with a color (green, blue, and yellow respectively).
Games will be required to display the age rating on their website as well as what is described as “relevant material” (likely including but not limited to retail boxes). The idea is that this will be a step toward protecting minors, something that the regulatory agency has used as a justification for several policy changes this year. It’s not altogether without precedent, as Tencent had proposed a similar system prior to this decision, but the important fact to note is that it’s not just a good idea but actual law for Chinese games.