Weapon Finesse
(Player's Handbook v.3.5, page 102, DnD 3.5)
[General, Fighter Bonus Feat]
You are especially skilled at using weapons that can BENEFIT: as much from Dexterity as from Strength.
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 (see page 38). Natural weapons are always considered light weapons.