You’ve learned how to kill with speed and grace, rather than with pure strength.
Prerequisites: Dexterity 13, Weapon Finesse.
Benefit: When wielding a finessable weapon you can add your Dexterity modifier instead of your Strength modifier to that weapon’s damage. The weapon must be one appropriate for your size.
In addition you can treat any light or one-handed slashing weapon as a light or one-handed piercing melee weapon for all feats and class abilities that require such a weapon (such as a swashbuckler’s or a duelist’s precise strike).
Special: A tiny or smaller creature may not take this feat.