Arcane Armor

When you cast this spell your body is surrounded by arcane sigils which firm a set of ethereal plate armor protecting your body. Until the spell ends, your AC can't be less than 16 regardless of what kind of armor you are wearing.

At Higher Levels. When you cast this spell at higher levels, your AC increases by 1 for every two starting at third level. 3rd and 4th level, AC 17. 5th and 6th level, AC 18. 7th and 8th level, AC 19. 9th level, AC 20.