srd
SRD
Prerequisites: Dex 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: A fighter may select Greater Two-Weapon Fighting as one of his fighter bonus feats.
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.
Open Game Content from the System Reference Document 3.5, used under the Open Game License 1.0a.