Do any of the newer D&D editions' books (most likely the DM Guide) have guidelines for granting experience for exceptional role-playing?
I once played with a professional DM (there's a job I want) who did that. I wasn't sure if that was common or if there were guidelines for such a thing.
Best Answer
While I think it's awesome to award experience for in-character behavior, it's also very hard to quantify role playing into experience (how much gets you 100exp?)
On top of that, in DnD, exp translates very observably to combat prowess - so it also makes sense to give other types of benefits.
Good role playing should give good role-playing benefits. If the character keeps in touch with their mother have their mother notice and do something when they've been imprisoned by the Necromancer for a week. If the player helps an old lady cross a river make her turn out to be the Godess Hera, who blesses them. If the character is a bigot and flips off a Dwarf in a tavern, have other bigots in the tavern for them to relate to, and turn them into contacts... etc