Your fantasy kingdom has an economy. Does it make sense?

You've built a world. It has a magic system, a political structure, and a map. But when your players ask "Why is there a thieves' guild in the capital?" you need the answer to hold up.

Run your world's premise through Yesbrainer. "A kingdom where magic is restricted to the aristocracy." The Economic lens shows black markets. The Social lens shows class resentment. The Political lens shows secret police. The Cultural lens shows underground folk traditions. The Ethical lens shows the philosophical justification the aristocracy tells itself.

Suddenly you don't have a setting. You have a world that feels real — because it follows the same logic as the real one.