Lightning Caltrops (Patreon)

Wondrous item, uncommon

These magic caltrops function like normal caltrops when scattered. When a creature takes lightning damage while standing on a space covered in these caltrops, that creature takes an extra 2d8 lightning damage. Once a creature in that space takes lightning damage in this way, or if the caltrops themselves are targeted by an effect that deals lightning damage, the caltrops become charged with electrical power. The caltrops remain charged for 1 minute or until a creature takes damage by stepping on them. Any creature that takes damage from stepping on the charged caltrops also takes an extra 2d8 lightning damage and can't take reactions until the start of its next turn. If a creature wearing metal armor steps on the charged caltrops and succeeds on the Dexterity saving throw, it still takes 1d8 lightning damage from the caltrops but does not end their charge.

If a set of lightning caltrops is scattered on the ground within 15 feet of another one, charging either set of caltrops also charges the other.

These damned things still make me mad. The whole mage assassin bit? Just an excuse to make more of these sadistic toys. And for what? A cheap "lightning never strikes the same place twice" joke? Downright evil.