Weapon (greatsword), 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 10 necrotic damage if it isn't a construct or an undead. You also gain 10 temporary hit points.
Proficiency with a greatsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.
Notes: Damage: Necrotic, Bonus: Temporary Hit Points, Healing, Damage, Combat, Heavy, Two-Handed
The "20 on the attack roll" is adding the proficiency and strMod? or is it only in crit hits, natural 20 ?
The wording says "roll a 20", I would assume this means without the modifier.