Greater Two-Weapon Fighting

Obsidian has mentioned the dual-wielding concept as well as it being a core DnD mechanic and a feature of the ranger class. This means greater two-weapon fighting is likely to be included in NWN2.

3.5 Greater two-weapon fighting
Type: General

Prerequisites: Dexterity 19, Improved two-weapon fighting, Two-weapon fighting, base attack bonus +11

Benefit: You get a third attack with your off-hand weapon, albeit at a –10 penalty.

Special: An 11th-level ranger who has chosen the two-weapon combat style is treated as having greater two-weapon fighting, even if he does not have the prerequisites for it, but only when he is wearing light or no armor.

NWN comparison

 * This feat did not exist in NWN.