Index of Spells by Theme Group - Armor, Natural

Grants +2 (or higher) enhancement to natural armor.

Barkskin toughens a creatures skin. The effect grants a +2 enhancement bonus to the creatures existing natural armor bonus. This enhancement bonus increases by 1 for every three caster levels above 3rd, to a maximum of +5 at caster level 12th.

The enhancement bonus provided by barkskin stacks with the targets natural armor bonus, but not with other enhancement bonuses to natural armor. A creature without natural armor has an effective natural armor bonus of +0.

You gain combat bonuses.

You become a virtual fighting machine stronger, tougher, faster, and more skilled in combat. Your mind-set changes so that you relish combat and you can't cast spells, even from magic items.

You gain a +4 enhancement bonus to Strength, Dexterity, and Constitution, a +4 natural armor bonus to AC, a +5 competence bonus on Fortitude saves, and proficiency with all simple and martial weapons. Your base attack bonus equals your character level (which may give you multiple attacks).

You lose your spellcasting ability, including your ability to use spell activation or spell completion magic items, just as if the spells were no longer on your class list.