On planet Gaia, every country is assigned a system. When a new country is born, so is a new system. The system receives a mentor to teach it how to do it's job properly.
Hey! Listen to me!
The system ensures that everything is functioning properly.
Sire! We have an emergency!
Inhabitants get assigned the right classes.
Not that class!
Dungeons are of the appropriate level.
I said to start with a low level one!
And everyone is happy.
Why!?! God! Why did you give me this class?
Except maybe in one country, where the system just does whatever it wants. The country is thrown into chaos and inhabitants have to figure out how to get things to work, when the system is doing everything wrong.