The material below is Open Game Content and originates in a 3rd party source here
School conjuration (creation) [force]; Level sorcerer/wizard 1, summoner 1, witch 1
Casting Time 1 standard action
Components V, S, F (a piece of cured leather)
Target creature touched
Duration 1 hour/level (D)
Saving Throw Will negates (harmless); Spell Resistance no
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.