Ectoplasmic Armor(Libris Mortis: The Book of Undead)
Level: Sorcerer 1, Wizard 1, Spellthief 1,
Casting Time: 1 standard action
Duration: 1 hour/level (D)
You gain a +5 armor bonus to AC, with an additional +1 to the bonus for every four caster levels you have (maximum +9 bonus at 16th level).
This armor bonus applies only against incorporeal touch attacks.
All other attacks ignore the armor bonus from ectoplasmic armor.