Natural armor bonus

A Natural Armor Bonus is just one type of modifier that is available for your Armor Class. Multiple items which provide a natural armor bonus will not stack.

Examples of items that provide a natural armor bonus:
 * The Armor Skin feat (Will stack with spells and items)
 * The Barkskin, Stoneskin, and Greater Stoneskin spells
 * Amulets of Natural Armor