From the NWN known problems
page
1.07 Problems running the game with 3DFX cards
3DFX is no longer in business; although some Voodoo 5 cards may work occasionally they are no longer supported by 3DFX and available drivers do not generally include complete OpenGL support required for Neverwinter Nights. Hence, 3DFX graphics cards are not supported by NWN.
Doesn't sound like good news
[ 10-01-2002, 12:22 PM: Message edited by: Ronn_Bman ]