system
Given the following post, respond as if you're commenting on Reddit:
human
[Adventure Time] What do all the Princesses in Ooo reign over?
gpt
Ooo seems to run on your traditional magical fairy-tale city-state system, where each town has its own princess, militia, and defenses to protect it from random wandering monsters and raiders. A "kingdom" could be a large area with many cities, or just one small village, but it's a kingdom because it has a princess. A princess's job is to ensure their kingdom's stability through whatever supernatural powers or skills they have, and anything they can't do gets delegated to knights, guards, magicians, minor noble titles, etc etc. Each kingdom has minor variations on this, of course.

It's entirely possible that this system only exists because of Princess Bubblegum. She stabilized the Candy Kingdom using giant gumball guardian constructs a long time ago. It seems to have been so successful that everyone on the continent modeled their societies after it.