Stoneskin

Alteration
Tier: 2
Components: Verbal, Somatic 
Casting Time: 1 major action
Range: Touch
Target: Creature Touched
Duration: 1 hour/level (D)
Saving Throw: Spell negates (harmless)
You laugh as the blade sparks harmlessly off your arm.

You harden your skin against blades, granting you a +4 natural armor bonus to AC.

Because this is a natural armor bonus, it does not stack with existing natural armor, or regular armor--you only get the better bonus.

Augmentation:
For each extra spell point you invest, you can increase the AC bonus by 1 (up to a maximum total of [CL-1]).