An ethereal barrier of spikes, made of magical force, interposes itself between you and an attacker. Until your next turn, when you are hit by a melee attack, the barrier reduces the damage you are dealt by 2d4, and deals the same amount of piecing damage to the attacker. the shield is ineffective against ranged attackers, but still provides a +2 bonus to AC (treat as half cover) against them for the duration.
At Higher Levels. When you cast this s/ell using a spell slot above 1st lv, increase the spells effect by an additional 1d4 for every slot above 1st.