As example windmill situation.
You can talk out bunch of goblins from attacking you. They all run away and you... gain nothing from it (other than avoiding combat).
"Now that sucks!" first thing most gamers would think right after. Reload. And proceed differently with killing every goblin.
So my first playthrough I did talk my way out of the fight. Now in my second playthrough I decided to kill all for XP. There is actually a 3rd scenario that can occur:
and that is (i'm not sure if it's because I almost immediately delivered a blow to their leader or if it's because I did it with Lae'zel and he wet himself quickly) that he will quickly beg for mercy at the beginning of the fight. You actually have the option to kill him but even though he dies, the rest of the fight stops because the rest of the goblins scram. You lose out on a bunch of XP in that situation as well since I only killed him and 1 other from a pack of like.. I forgot like 8 or 10 strong.