By swearing to never use a weapon other than a longsword, you can achieve things normally limited to the most highly trained swordsmen.
Prerequisite: Proficient in longsword, Weapon Focus (longsword), base attack bonus +4.
Special: If you ever use a melee or ranged weapon other than a longsword in combat, you lose the benefits of this feat until you receive an atonement spell. You may still use spells that act as weapons (such as flame blade and spiritual weapon) without affecting your oath.
Pathfinder 26: The Sixfold Trial
Pathfinder 26: The Sixfold Trial. Copyright 2009, Paizo Publishing, LLC; Author: Richard Pett