Adventures in Underdark
Game Rule Changes
Shield/Deflection bonuses no longer stack
All “enhancement/deflection/natural armor/class ability/resistance” bonuses from magic items and spells remain intact (with minor exceptions). “Morale/competence/luck/size” bonuses are now considered buff bonuses, and stack with all other bonuses, but not with each other. The notable exception to these rules is the spells Protection from Evil, Magic Circle, and Holy Aura, which provide resistance and deflection bonuses, but will now provide a buff bonus.
Eliminate “inherent” bonus to stats from books. Eliminate stat buffs from polymorph and size.
Off-Hand attacks are limited to 1