New mechanic idea

This idea is a bit half-baked. Maybe you can help me fill it out.

The idea is to have "Fame Points" (FP) and levels of fame. Similar to Renown, Fame would track how widely known your party is in the world. Would everyone spanning an entire continent know your name, or only in certain circles? Would even a few people from across the seas know of your deeds?

I'm not sure if these would come with any in-game mechanical benefit, but simply by tracking it, players would be motivated to optimize it. It might simply affect role-play. How easy is it to recruit help or get special do-gooder discounts. Depends on your fame. Recently my paladin tried to negotiate a "saving the city" discount on a magic spear. He only got a small one, because lots of people were fighting in the battle and might also want the spear. If his party was more famous, the shopkeeper would have said, "Certainly, for a member of the Vicit Venators."

Or, what in-game benefits might you give?

Charisma ASIs?

Bonus feats?

A small gold income representing fan club donations, a stipend from the Church for your order holy knights, taxes from the subjects of your fiefdoms, or allowance from your group patron

Sounds interesting. I might use this. Instead of increasing Charisma, I would have the number of fame points they gain whenever they gain them depend on their Charisma modifier (minimum 0), as we all know that generally-known history is far less than totally accurate.

On another finger, shopkeepers have a business to run. Full price without a Charisma check is always the case. I might lower the DC of the check, though, if they invoke that being famous will draw business.

If you grant fame points in different categories, that's basically faction renown. Your factions are Church and State, among others.

Shadowrun and Cyberpunk both have similar systems. You may find some useful stuff by looking into how those systems handled it.