“ <br />
The local band of 'nasties' (goblins / orcs / whatever) lives in relative peace with the local population.<br />
Along come the PCs and go through their usual heroic monster bashing routine, wiping out the nasties and pinching all their stuff, then continue on their way.<br />
Problem is, they don't kill ALL he nasties. The survivors want revenge and, after spending a few months recovering, start to take it in their own inimitable style (which is not unlike that of the PCs come to think of it).<br />
Next time the PCs are in the area they find themselves VERY unpopular with the townsfolk.”
“ After killing certain animals, if you drink their blood while performing a sort of ritual you will have visions and/or gain specific powers for an amount of time.”
“ In one region of a forest, all of the trees are identical, down to the leaves and the twigs. If the PCs carve something into one of the trees, it could mystically propigate until it covered all of the trees, or could vanish since it was not carved into the one true tree.”