You have mastered the impenetrable fighting style.
Benefit(s): You gain a +2 bonus on initiative checks as long as you start combat with a dueling sword in your hand. As long as you wield only a single dueling sword in one hand (not using a shield, an off-hand weapon, armor spikes, unarmed strikes, or natural weapons), you gain a +2 shield bonus to your AC. If you wield the sword in two hands, this bonus drops to a +1 shield bonus to AC. Although the dueling sword deals slashing damage, you treat it as if it were also a piercing weapon when determining the effects of weapons used by a duelist or swashbuckler.
Pathfinder Roleplaying Game Adventurer’s Guide © 2017, Paizo Inc.; Authors: Benjamin Bruck, John Compton, Crystal Frasier, Tim Hitchcock, Jenny Jarzabski, Isabelle Lee, Joe Pasini, Jessica Price, David Schwartz, and Josh Vogt.