The copyright stuff I don't really understand..Duergar is the old Norse word for dwarves...
At the moment we are using Deep dwarf, Deep gnome, and dark elf. WotC lawyers have big big teeth people.Really big. And pointy.
This is basically the deal.Right now, we're still playing with a WotC-sanctioned game engine, but at the same time, we're formalizing our world lore. Regarding the names of creatures and things, there's no reason to change their names at this time. Some may be copyrighted, others not, but that doesn't matter now, as we're using the NWN engine.In terms of world lore issues though, for the foreseeable future the races are being termed as Honora has mentioned above.