Arcane Armor Training
You have learned how to cast spells while wearing armor.
Prerequisites: Light Armor Proficiency, caster level 3rd.
Benefit: As a swift action, reduce the arcane spell failure chance due to the armor you are wearing by 10% for any spells you cast this round.
Endzeitgeist Says: Generally, a primary caster can provide better magical protection than armor with only 10% arcane spell failure can grant. If you do not absolutely wish to play an arcane caster with armor, this may not be the best choice. If that is your concept, though, go for it. It can be efficient.