This spell uses the 2e rule set.
A critical hit only removes a single skin.
Stoneskin – Dwarf
Priest Spell Compendium Volume 3 page 605
Sphere: Elemental Earth
Components: V, S, M
Casting Time: 1
Area of Effect: 1 creature
Saving Throw: None
When this spell is cast, the affected creature gains a virtual immunity to any attack by cut, blow, projectile, or the like. Even a sword of sharpness cannot affect a creature protected by stoneskin, nor can a rock hurled by a giant, a snake’s strike, etc. However, magical attacks from such spells as fireball, magic missile, lightning bolt, and so forth have their normal effects. The spell’s effects are not cumulative with multiple castings.
The spell blocks 1d4 attacks, plus one attack per two levels of experience the caster has achieved. This limit applies regardless of attack rolls and regardless of whether the attack was physical or magical. For example, a stoneskin spell cast by a 9th-level wizard would protect against from five to eight attacks. An attacking griffon would reduce the protection by three each round; four magic missiles would count as four attacks in addition to inflicting their normal damage.
The material components of the spell are granite and diamond dust sprinkled on the recipient’s skin.
Notes: Very rare spell granted by some dwarven deities, identical to the 4th-level wizard spell of the same name.