Heh, I'm still playing this as well. Good ol' game.
I used to have this manual with some of the best builds ever created for NWN. They're all power builds though and no RP - so if role playing is what you enjoy, don't look there.
me self prefers RP builds than powergaming. Those powergaming always forgot they started at level 1 instead of 40 right out. Actually, there be no such power-builds, only a build which is better at certain condition, not for all conditions. Regardless, if u maxed u'r level, everyone came relatively same.
Suppose we have a Mage / Sorcerer with Premonition up. A Ranger somewhere shoots an arrow at him, and hits (i.e. damage gets absorbed by Premonition).
Where does the arrow go? Does it just clatter onto the ground? Does it get absorbed as well (and disappear)? Does it vanish in a blaze of sparks? Can someone else pick it up and use it?
Well, in that case, RP-wise, the arrow never hit the wizard in the first place. It just past through. Hitting air.
The arrow's "damage gets absorbed by the magic" is the game's simulation of what happened when the wizard simply evade it.
Premonition is a divination spell, it allows the caster to divine where he would get hit by a physical blow, and accordingly, evade that location. Thus, when the blow actually happened, he already get out of the danger.
This is like if u're standing on a rail, and a train come to u. U predict that within the next 15 secs the train will be in u'r location, and u'll get hit. So, to avoid getting hit, u simply move out of the rail within that 15 secs.
In game, powerful weapon (with more than +5 enchantment) is so difficult to prevent either because it can interferes directly with the magic flow used for the divination thus disrupting the spell, undetected by the magic, or simply by-pass the premonition attempts.