Ethereal Armor

You surround yourself in a ghostly, ethereal armor, made up of coalescing wisps of magic. While the spell is active, you gain a +3 to AC, and you cannot be targeted by the magic missile spell. 

At Higher Levels. When you cast this spell with a spell slot of 4th level or higher, you gain an additional +1 increase for each spell slot level above 3rd to a maximum total of +5. Additionally, you gain the ability to see into the ethereal plane while the spell is active.