Bartholomew Black's Brooch of Shielding

While wearing this brooch, you have Resistance to Force damage, and you have Immunity to damage from the Magic Missile spell.

Once per long rest, as a Reaction you may activate this brooch until the start of your next turn. While activated, the brooch provides +3 to Armor Class against nonmagical attacks. 

Notes: Resistance: Force, Warding, Jewelry