This challenge is generally based upon, related to, or simulates a game or some portion of one.

In addition to (or instead of) this tag, you might want to use one of the following more specific ones:

For specific types of games, you can also use , , .

This tag can be used on KotHs, but should be reserved for those which are based on real-world games (as all KotHs are, in a sense, games).