Necrotic Spells
Here is a list of foundational damage spells that Necromancers can use to flesh out their library, pun intended and not just be bound to raising the dead.
Dying Gasp
Level 2 Necromancy (Warlock, Wizard)
Casting Time: Action
Range: Self
Components: V
Duration: Instantaneous
You gently exhale a sweeping cloud of mist that sweeps over creatures in a 20-foot Cone originating from you. Creatures in the Cone make a Constitution saving throw or else take 4d8 Necrotic damage and become unable to regain Hit Points for 1 minute. On a pass, they take half as much damage only.
Using a Higher-Level Spell Slot. The damage increases by 1d8 for each slot level above 2.
Skull Blast
Level 2 Necromancy (Warlock, Wizard)
Casting Time: Action
Range: 60 feet
Components: V, S, M (A shrunken head)
Duration: Instantaneous
You create a flaming, green skull and launch it at a creature within range. Make a ranged spell attack against the target. On a hit, you deal 3d8 Necrotic damage and an explosion of flames appears. The target and each creature within 5 feet of it must succeed a Dexterity saving throw or take 2d6 Fire damage.
Using a Higher-Level Spell Slot. The Fire damage increases by 1d6 for each spell slot level above 2.
Night’s Cloak
Level 3 Necromancy (Warlock, Wizard)
Casting Time: Action
Range: Self
Components: V, S, M (a black cloth)
Duration: Concentration, up to 10 minutes
For the duration you cloak yourself in shadows made of wailing ghouls. You gain a +1 bonus to AC. This bonus increases to +2 while you are entirely within Dim Light or Darkness.
As part of casting this spell, or as a Magic action on a subsequent turn, you can enshroud yourself in the cloak, gaining 3d8 + your Spellcasting ability modifier Temporary Hit Points, that last until the spell ends. While these Temporary Hit Points persist, when a creature you can see attacks you with a melee weapon attack, it takes 2d8 Necrotic damage. A creature can take this damage only once per turn.
Using a Higher-Level Spell Slot. The Temporary Hit Points increase by 1d8 for each spell slot level above 3.
Heart Attack
Level 4 Necromancy (Warlock, Wizard)
Casting Time: Action
Range: 30 feet
Components: V, S, M (a wooden heart)
Duration: Concentration, up to 1 minute
You grip a creature’s heart with necrotic energy. You force a creature in range that you can see to succeed a Constitution saving throw or take 4d10 Necrotic damage and suffer from Disadvantage on Strength and Constitution saving throws for the duration. At the end of each of the target’s turns, they make a Constitution saving throw, which does not suffer Disadvantage due to the spell. Of a failure, the target takes 2d10 Necrotic damage. On a success, the spell ends. Creatures without hearts are immune to the effects of this spell.
Soul Haze
Level 4 Necromancy (Warlock, Wizard)
Casting Time: Action
Range: Self
Components: V, S
Duration: Instantaneous
You reave the nearby life force from nearby creatures, dragging it into you. Each creature of your choice in a 20-foot Emanation, originating from you, must make a Constitution saving throw. On a failed save a target takes 6d6 Necrotic damage. On a pass, creatures take half as much damage.
You gain 2d6 Temporary Hit Points for each creature that failed this saving throw, up to a maximum of 10d6.
Using a Higher-Level Spell Slot. The damage and maximum Temporary Hit Points increase by 1d6 for each spell slot level above 4.
Spite Soul
Level 6, Evocation (Cleric, Warlock)
Casting Time: Action
Range: 30 feet
Components: V, S, M (a cursed gemstone worth 5000+ GP, which the spell consumes)
Duration: Instantaneous
You attempt to purge a creature’s soul of purity. One creature you can see within range must succeed a Charisma saving throw or take 10d8+10 Necrotic damage. Evil creatures make this saving throw with Advantage.
If a Good Humanoid is reduced to zero Hit Points by this spell, they instantly reincarnate in a random harmless location on the plane that you are on, losing their memories and using a commoner’s stat block. Their alignment is changed to Evil. Only the Wish or a form of Divine Intervention can reverse this effect.
Necrotic Plague
Level 9 Necromancy (Warlock, Wizard)
Casting Time: Action
Range: 120 feet
Components: V, S, M (a black diamond worth 20,000+ GP, which the spell consumes)
Duration: Instantaneous
You force creatures of your choice within range to make a Constitution saving throw. On a failed save they take 20d10 Necrotic damage, or half as much on a success.
A humanoid killed by this spell rises at the start of your next turn as a zombie that is permanently under your command, following your verbal orders to the best of its ability. Humanoids killed by these zombies also rise as zombies, which are likewise under your command and able to convert others.