3e SRD:Improved Two-Weapon Fighting
From D&D Wiki
|This material is published under the OGL|
Improved Two-Weapon Fighting [General]
Prerequisite: Two-Weapon Fighting, Ambidexterity, base attack bonus +9 or higher.
Benefit: In addition to the standard single extra attack the character gets with an off-hand weapon, the character gets a second attack with the off-hand weapon, albeit at a -5 penalty.
Normal: Without this feat, the character can only get a single extra attack with an off-hand weapon.
Special: A ranger who meets only the base attack bonus prereqs can gain this feat, but can only use it when wearing light armor or no armor.