Creatures other than you see a wavering field of energy around you. If a creature hits you with an attack or spell, the damage is reduced by 1d8 and the attacker takes that much psychic damage. Once a creature has taken the damage or the duration has passed the spell ends.

At Higher Levels: When you cast this spell using a spell slot of 2nd level or higher, both the damage reduction and the psychic damage increase by 1d8 for each level above 1st.