Earth: Real world, Fantastic Earth, Archaic Earth, Alternate history, Future Earth, Dying Earth, Lost lands

Parent: (not to be marked in most cases)
* Sol star system

Related:
* Luna
* Extraterrestrial - including planets, the interstellar/-planetary space, and such.
* Parallel world - in case it's within the same "universe" as Earth

Contrast:
* Constructed universe

Since nothing in the game flags tell where the game takes place (not even hinting on it, except with historical games), this is to identify cases which definitely are set on Earth, even if the more specific location is fictional.

This is in relation to the "real world", so this does NOT apply to cases where the planet or world is called Earth but has no relation (world map is randomly generated) to the real thing.

However, fictional locations on Earth do count.