You use shields not just for protection but also for offense. You gain the following benefits while you are wielding a shield:

• Shields you wield count as Melee Weapons for you that you are proficient with. They deal 1d6 bludgeoning damage and have the Heavy Property. If the shield has the spiked property, you may choose to deal piercing damage instead of bludgeoning with attacks made with that shield. If the shield has the bladed property, you may choose to deal slashing damage instead of bludgeoning with attacks made with that shield. 
• Shields you wield that have a magical bonus to defense also apply the same bonus to attack and damage rolls when you use that shield as a weapon.