Battery Shield

Armor (shield), uncommon

This shield builds up a small electrostatic charge while worn. When a creature makes a melee attack against you using a metal weapon and the attack roll misses by 2 or less, that creature takes 1d4 lightning damage.

The shield rang out like a bell as it stopped the dwarf's hammer mid-swing. The wiry gnome behind the shield popped out a moment later, grinning ear to ear as they said, "Well, nows I've gotta charge ya with assaultin' a battery!"

In confusion, the dwarf replied through gritted teeth, "Don't you mean, assault and—"

Click.

And the shield sparked to life.