CreamCloud0
Hero
Players getting bonus exp for being lucky is the more preferable option in my books than rewarding them for purposefully dragging encounters out as was mentioned as a flaw of the 'longer battles>>more exp' method in previous posts.Note that could have the unintended side-effect of causing the xp value of any given combat to in part be determined by sheer luck of the dice, regardless of any planning (or not) done by the players/PCs.
If that's an intended result, however, all is good.
but yes, idealy it would be for rewarding for players for fighting smarter than just being lucky.
I don't know if it was clear in my first post but going over the encounter's 'par' wouldn't cut into the exp given, just bonuses for being more efficient.