Bladeproof skin

(Unearthed Arcana, page 92, DnD 3.5)

[Spelltouched]

Your skin has a degree of protection from even the sharpest edge.

Prerequisite

Exposure to stoneskin or iron body spell

Benefit

You gain damage reduction 3/bludgeoning. Your skin imposes an armor check penalty of -2 (which stacks with the armor check penalty from armor and shield).