You don’t take an armor check penalty or incur a arcane spell failure chance when wearing light armor or using a shield (including a tower shield). In addition, the maximum Dexterity bonus of light armor doesn’t apply to you. You can select this ability up to three times. The second time, it also applies to medium armor. The third time, it also applies to heavy armor.
Pathfinder Roleplaying Game Mythic Adventures © 2013, Paizo Publishing, LLC; Authors: Jason Bulmahn, Stephen Radney-MacFarland, Sean K Reynolds, Dennis Baker, Jesse Benner, Ben Bruck, Jim Groves, Tim Hitchcock, Tracy Hurley, Jonathan Keith, Jason Nelson, Tom Phillips, Ryan Macklin, F. Wesley Schneider, Amber Scott, Tork Shaw, Russ Taylor, and Ray Vallese.