[Mark Sir Link]

A glitch has been discovered by Zippy (Jacob_Bald6225) in which you can add indoor levels to an overworld (or whatever gmap available) to bypass NPCs. It works using any of a servers gmap. If you simply save an non included level over the original filename, and proceed to enter that room, all NPCs vanish. However, while bringing up this glitch, I also pose a temporary fix. Simply use setshape for all NPCs from now on, and you will have no issues. Beware, though, of players sneaking through quests.

-EDIT:
basically, the NPCs scripts are inapplicable, so if a NOPK NPC is set up, you can PK. If weapons are disabled, they're still enabled. If your using an NPC to block things, they don't work unless setshape is active.