3rd edition D&D rules that the game uses have been implemented very well. The multitude of selectable skills and feats makes for very varied characters, and leveling up is not simply a routine, but an important event where you decide which additional skills and feats your characters would benefit from. "Annals of Halgren", the pre-made party I played with had a sorcerer that could finally use a crossbow! After Neverwinter Nights this might seem nothing special, but for anyone used to previous AD&D Infinity Engine games, this means much more - a totally different approach to tactics at the very least. Mages are not simply fragile porcelain that needs to be at the back of the party all the time, but can hold their own in battle. Ask my armour-clad sorcerer if you don't believe me.