Casting Time 1 standard action
An invisible but tangible field of force surrounds the subject of a mage armor spell, providing a +4 armor bonus to AC.
Unlike mundane armor, mage armor entails no armor check penalty, arcane spell failure chance, or speed reduction. Since mage armor is made of force, incorporeal creatures can’t bypass it the way they do normal armor.
Pathfinder RPG Core Rulebook. © 2009, Paizo Publishing, LLC; Author: Jason Bulmahn, based on material by Jonathan Tweet, Monte Cook, and Skip Williams.