Do Realms count as Planets?

Depends on how you define them in your stories. Going by the definition, it’s usually just a kingdom/nation. For some folks, a realm is more like another dimension, not a planet. Some may even use it to define regions/territories instead of nations. Some (myself included in this one lol), use realm interchangeably with ‘world’ or ‘planet’, sometimes dimensions too (like a pocket dimension).

So, it mostly just depends on how you want to interpret it, and if it works better for the cultures in that world.

For me, it always gives a more elegant, refined tone to describing a planet (Earth vs the Realm of Earth lol). So, I usually use it for worlds where I have a lot of very proper or aristocratic people/races. But, that’s just how I use it.

Anyway, hope this helps!