Sword of Life Stealing (Rapier) 2014
Weapon, rare, (requires attunement)
When you attack a creature with this magic weapon and roll a 20 on the attack roll, that target takes an extra 3d6 necrotic damage, provided that the target isn't a construct or an undead. You gain temporary hit points equal to the extra damage dealt.
Properties
Finesse
When making an attack with a finesse weapon, you use your choice of your Strength or Dexterity modifier for the attack and damage rolls. You must use the same modifier for both rolls.
Other versions
Source: System Reference Document 5.1 (Wizards of the Coast) · License: Creative Commons Attribution 4.0 / OPEN GAME LICENSE Version 1.0a details