Can a spell like Vampiric Touch drain life from a creature that is already at 0 HP?

Can a spell like Vampiric Touch drain life from a creature that is already at 0 HP?

I can’t really be sure if the “no negative HP” rule means that the damage taken when in 0 HP does not “count” for Vampiric Touch if it’s not “Massive Damage”.

Example: A character uses Vampiric Touch on another character at 0 HP (with advantage and it’s a critical). They roll for damage, which by chance, is not enough to be “Massive Damage” (the Max HP of the fallen creature). Does the caster heal himself, or is the effect wasted due to the “no negative HP” rule?

Does casting Inflict Wounds while concentrating on Vampiric Touch also siphon damage?

Vampiric Touch says,

The touch of your shadow-wreathed hand can siphon force from others to heal your wounds. Make a melee spell attack against a creature within your reach. On a hit, the target takes 3d6 necrotic damage, and you regain hit points equal to half the amount of necrotic damage dealt. Until the spell ends, you can make the attack again on each of your turns as an action.

Scenario:

  • Round 1 you cast vampiric touch and make a melee spell attack for 3d6 necrotic damage.

  • Round 2 while still concentrating on vampiric touch you cast Inflict Wounds as a 3rd level spell for 5d10 necrotic damage.

Being that Vampiric Touch is still functioning, you are making a melee spell attack, and it is dealing necrotic damage… Does the necrotic damage from Inflict Wounds siphon health?

(Obviously the 3d6 and 5d10 wouldn’t stack because of action economy, etc.)

I am sure that a player could find a better use of two 3rd level spell slots, but I have taken up a kind of awkward place as an arcane healer/tank for the group and every bit of preservation helps.

Does the warlock’s Gift of the Ever-Living Ones eldritch invocation change how the Vampiric Touch spell behaves?

The warlock’s Gift of the Ever-Living Ones (XGtE p. 57) eldritch invocation is described as follows:

Whenever you regain hit points while your familiar is within 100 feet of you, treat any dice rolled to determine the hit points you regain as having rolled their maximum value for you.

The description of the Vampiric Touch (PHB p. 285) spell states:

On a hit, the target takes 3d6 necrotic damage, and you regain hit points equal to half the amount of necrotic damage dealt.

How do these two interact? Do I roll for damage, and then gain 9 hit points?

Vampiric touch and 2- weapon fighting [on hold]

Once I have cast Vampiric touch I can make a melee spell attack. In the first round, the round I cast the spell my action is to ‘cast a spell’ and a I clearly can not use two-weapon fighting. However, in subsequent rounds my action is to make an attack. Does this attack allow me to use the two-weapon fighting rule and make an attack with a light weapon in my off hand as a bonus action?

Two-weapon fighting stipulates that you must make an attack with a weapon. So the crux of the question: is a melee spell attack with Vampiric touch equivalent to attacking with a weapon? I would consider a hand that can do 3d6 necrotic damage a weapon.

Is the homebrew weapon attack cantrip ‘Vampiric Assault’ balanced?

I have created some new cantrips which include making a weapon attack as there are only two official ones to choose from. I’ve tried to follow these principles based on Booming Blade and Green-Flame Blade:

  • Melee weapon attack only, 5 foot range
  • No unavoidable extra damage to the primary target at level 1
  • Damage no more than 2 targets
  • Spellcasting ability modifier doesn’t have to affect the spell at all
  • Only available on the Warlock, Sorcerer and Wizard spell lists

But with such a small amount of official content to compare them against, it’s hard to say if they’re balanced.

Is this spell balanced with Booming Blade and Green-Flame Blade?

Vampiric Assault

Necromancy cantrip

Casting Time: 1 action
Range: 5 feet
Components: V, M (a weapon)
Duration: 1 round

As part of the action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell’s range, otherwise the spell fails.

On a hit, the target suffers the attack’s normal effects, and if it takes any damage from the attack, you gain temporary hit points equal to your spellcasting ability modifier (minimum 1). The temporary hit points are lost at the end of your next turn.

At 5th level, the attack deals an extra 1d6 necrotic damage to the target. The damage roll increases by 1d6 at 11th level and 17th level.

If someone casts Vampiric Touch on a creature with necrotic absorption, does the caster take damage?

Leaving aside the question of if there’s any way in the manual for anyone to have necrotic absorption in 5e (which as far as I know isn’t the case), and given the text of Vampiric Touch as follows, would attacking a creature that heals from Vampiric Touch do damage to the caster? Vampiric Touch:

Make a melee spell attack against a creature within your reach. On a hit, the target takes 3d6 necrotic damage, and you regain hit points equal to half the amount of necrotic damage dealt. Until the spell ends, you can make the attack again on each of your turns as an action.

It has been brought to my attention that damage absorption is not actually a keyword. The following explanation is sourced from The Rise of Tiamat (aka Tyranny of Dragons) campaign, attached to the dragon masks.

Damage Absorption. […]whenever you are subjected to damage of that type, you take none of that damage and regain a number of hit points equal to half the damage dealt of that type.