Weapon (longsword), 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 longsword 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, Versatile
Do the temp hp stack for each hit? Do you receive them only when you hit nat 20 or any time you hit?
Temp HP never stacks. If you have multiple sources of temp HP, you can choose which one to use (which generally means "take the highest"), but they don't keep adding up.
Since the temp HP is equal to the extra necrotic damage dealt, and it's called "longsword of life stealing", I believe the HP are supposed to be drawn from the target and transferred to you. On that interpretation, since the sword does zero bonus damage on any round that you don't roll a natural 20, the temp HP in that case would also be zero. So even if temp HP stacked (which they don't), there would be no effect except on a natural 20.
And even on a natural 20, you wouldn't bother with the 10 temp HP from your longsword of life stealing if you currently have more than 10 temporary HP from another source (for example, Tomb of Levistus or Heroes' Feast)..
I'm trying to calculate my carry weight? Does anyone have an idea how much this sword weighs?
4 pounds
How much does one of these sell for?
Longsword is 3lb