A 'CASTE' OF REALISTIC CHARACTERS: Build role-playing possibilities on a social structure

The beggar on Glenview Bridge is a 14th level magic-user, laying low after a scuffle with the druids - who are turn hiding out disguised as cattle on a nearby farm.

A social system helps provide ideas for character background: What happened to him in those 16-19 years that a fighter spent before becoming a professional?

Or, more probably, is anything known about a town that could lead to inside information, the intrigue of politics and power, or simply who to talk to to get a regeneration spell?