Protection from Evil Spell
D&D Description of the Protection from Evil Spell : This spell wards a creature from attacks by evil creatures, from mental control, and from summoned creatures. It creates a magical barrier around the subject at a distance of 1 foot. The barrier moves with the subject and has three major effects.
First, the subject gains a +2 deflection bonus to AC and a +2 resistance bonus on saves. Both these bonuses apply against attacks made or effects created by evil creatures.
Deeper info on this Dungeons & Dragons Protection from Evil Spell