srd
SRD
Prerequisite: Base attack bonus +1.
Benefit: With a light weapon, rapier, whip, or spiked chain made for a creature of your size category, you may use your Dexterity modifier instead of your Strength modifier on attack rolls. If you carry a shield, its armor check penalty applies to your attack rolls.
Special: A fighter may select Weapon Finesse as one of his fighter bonus feats.
Natural weapons are always considered light weapons.
Open Game Content from the System Reference Document 3.5, used under the Open Game License 1.0a.