Lucky Draft

Heroic Tier
Prerequisite: Halfling, artificer, Healing Infusion class feature
Benefit: Instead of gaining the normal benefit for ending the effect of your resistive formula or shielding elixir, an ally benefiting from either of these powers can end the effect as a free action when hit by a melee attack to force the target to reroll the attack roll.

Published in Dragon Magazine 387, page(s) 34.