Some shields reduce magical attacks.

There is known to be a shield that has power in battle as an item.

SHIELDS

  Leather Shield
        buy = 90
        sell = 45
        def = 4
        classes = Hero, Soldier, Pilgrim, Merchant, Sage
    Small Shield
        sell = 45
        def = 4
        classes = Hero, Soldier, Pilgrim, Merchant
    Scale Shield
        buy = 180
        sell = 135
        def = 7
        classes = Hero, Soldier, Pilgrim, Merchant, Sage
    Large Shield
        buy = 400
        sell = 200
        def = 10
        classes = Hero, Soldier, Merchant, Pilgrim, Sage
    Iron Shield
        buy = 650
        sell = 478
        def = 12
        classes = Hero, Soldier, Merchant, Pilgrim
    Magic Barrier
        sell = 1
        def = 15
        classes = Wizard, GoofOff, Sage, Pilgrim
        info = While not an actual shield,  this barrier can protect those that can't use shields.
    Zenithian Shield
        def = 19
        classes = Hero
        info = Part of the Zenithian equipment set.
    Dragon Shield
        buy = 7100
        sell = 3525
        def = 30
        classes = Hero, Soldier
    Silve rShield
        buy = 8800
        sell = 6600
        def = 35
        classes = Hero, Soldier, Pilgrim, Sage
    Shield of Strength
        sell = 9750
        def = 40
        classes = Hero, Soldier, Merchant, Pilgrim
        info = A shield with the power of Healmore built in.
    Shield of Heros
        def = 45
        classes = Hero
        info = A shield that once belonged to the great hero,  Erdrick.
    Aeolus Shield
        sell = 3525
        def = 50
        classes = Hero, Soldier
    Metal Babble Shield
        def = 60
        classes = Hero, Soldier, Pilgrim, Merchant, Sage
        info = The best shield in the world.