School enhancing / necromancy; Level necromancer 2
CASTING
Casting Time 1 standard action
EFFECT
Range personal
Target you
Duration 1 minute/level
Saving Throw none; Spell Resistance no
DESCRIPTION
Your blood becomes as hard as iron upon contact with air.
Each time you take at least 5 points of piercing or slashing damage, your armor gains a +1 enhancement bonus to your AC. An outfit of regular clothing counts as armor that grants no AC bonus for the purpose of this spell. This enhancement bonus stacks with itself, but not with an existing enhancement bonus, to a maximum enhancement bonus of +5. This spell has no effect while underwater or in environments that lack air.
Bone armor is just all-encompassing enough to gain this bonus, but is removed if the bone armour is dispelled or otherwise ends.