Stoneskin

Stoneskin (Thaumaturgy) [Earth]
Level: Mage 4, Earth 5, Ranger 4
Mana: 35. Persistant. Base Success: 100%.
Turns your skin as hard as rock, automatically and completely negating 1d4+(caster level/2) blows from any weapon of less than +5 enchantment. Critical hits damage you, but only as much as a normal hit would usually.