Leopold said:
So far the character that I've been playing single player with is a Fight. 3/Sorc. 3, and it's working nicely.
I've hired both an NPC Rogue and and NPC Cleric, and what I saw of them in action made we want to play each of those classes big time. You have to see a Cleric turning undead zombies -- you will want to convert to their religion on the spot!
As someone else pointed out, the single player game is a 30 pt. buy campaign, which makes some multiclassing a little tough but not impossible. IIRC someone who's running a server is free to set up a pt. buy at whatever value they desire, so not all games are necessarily going to be 30 pt. games.
I'd call it about 95% 3rd edition. There are some small liberties taken based on the limitations of computer gaming as a medium, but I haven't seen a single thing that's pissed me off because it's a small departure from 3e. For example, there's no Whirlwind Attack feat -- I'd guess because Whirlwind Attack and Cleave are so similar, but the first time you see your character Cleave through a horde of goblins, trust me you'll howl with glee. Power Attack is preset to 5 pts., but this makes a tremendous amount of sense because of the realtime nature of the game -- there's simply no time to enter a custom value for a Power Attack. To compensate they've added a Greater Power Attack feat that's a 10 pt. attack, so you have additional flexibility as a mid-level fighter.
I think some very hardcore 3e fans will complain mightily about these small changes. IMO they don't really have an understanding of how computer gaming works as a medium. If you played BG, BG2, or IWD you know that those games weren't 100% 2nd ed. rules, but they were really close, close enough that the familiarity with the rules system made you happy. I swear to you, NWN is the same way with 3e. Run to your store and pick up a copy -- if you enjoyed BG and IWD, you will love this game.