Shield of Absorption (5e Equipment)

Armor (shield), common (requires attunement)

While this shield is attuned and wielded, you can activate it as a reaction whenever you take a specific type of damage. You have resistance to the triggering damage type until the start of your next turn, including the damage that triggered your reaction. After it is activated, the shield is no longer attuned, and becomes nonmagical.
The DM chooses the damage type, or determines it randomly from the options below.