You have mastered the ability to cast spells while wearing armor.
Benefit: As a swift action, reduce the arcane spell failure chance due to the armor you are wearing by 20% for any spells you cast this round. This bonus replaces, and does not stack with, the bonus granted by Arcane Armor Training.
Pathfinder RPG Core Rulebook. Copyright 2009, Paizo Publishing, LLC; Author: Jason Bulmahn, based on material by Jonathan Tweet, Monte Cook, and Skip Williams.