Eldritch Evoker (Warlock Invocation)

[John Cribati]

So I have two ideas for this, but in principle it’s the same: allow a Warlock to change the damage type of Eldritch Blast. I have two options here, but they both have the same prerequisites, so I’ll be leaving that the same.

Eldritch Evoker:
Warlocks who are diligent in their study of the arcane arts are able to alter the properties of their Eldritch Blast.

Prerequisites: The Eldritch Blast cantrip, Proficiency in the Arcana skill

Spoiler: Option A

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Whenever you deal damage with Eldritch Blast, you may choose to have the cantrip deal acid, cold, fire, lightning, necrotic, poison, psychic, radiant, or thunder damage instead of force. If you do, roll an Arcana check (DC25), and if you fail, the creature takes half the damage. If you know a spell that deals the same type of damage as the type you wish to change to, the check is rolled with Advantage.

Spoiler: Option B

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Choose a damage type: acid, cold, fire, lightning, necrotic, poison, psychic, radiant, or thunder. Whenever you cast Eldritch Blast, you can choose to deal that type of damage instead of force damage.

At tenth level, and again at fifteenth level, you can choose an additional damage type.

If you have or obtain Expertise in Arcana, you can choose an additional damage type.

When you gain levels in Warlock and have the option to replace Your known invocations, you can instead change one or more of your Arcane Evoker options.

[JNAProductions]

Option B, all the way. Option A adds a lot of dice rolling for minimal effect, and makes the invocation really bad.

As an invocation, Option B looks fine.

[BerzerkerUnit]

At a glance both seem too fiddly.

Give it a prerequisite of Level 12 and let the warlock freely swap damage types. While that makes an interesting concept, by and large this is a self nerf unless the PC has MM knowledge of resistances, immunities, and vulnerabilities and in 99.9% of cases, Force would function just as well or better.

Spells that deal those damage types, particularly at cantrip level, often have riders like reduced speed for cold or no reaction for lightning. The less resisted types have no rider (Thunderclap, Acid splash) and the commonly resisted types have above average damage dice (poison spray, firebolt).

If you expanded this to maybe # of times = proficiency you can choose the damage type instead of force and provided a rider for each one, that would create a lot of interesting options.

Acid- A target hit by your eldritch blast takes half the damage of the first blast at the start of its next turn. (this encourages spreading the blasts out but is still an upgrade to single target)

Cold- A target damaged by your eldritch blast has its speed reduced by 20 feet until the beginning of your next turn.

Fire- A target damaged by your eldritch blast is lit ablaze and suffers 1d4 fire damage at the end of its turn until it or another creature uses an action to extinguish it.

Lightning- A target damaged by your eldritch blast cannot take reactions until the end of your next turn.

Thunder- A target damaged by your eldritch blast emits a loud crack audible up to 300 feet away and is pushed 10 feet.

Poison- A target damaged by your eldritch blast becomes the center of a toxic cloud until the beginning of your next turn. Creatures that start their turn or move within 5 feet of it must make a con save vs your spell DC or be blinded until the end of their next turn.

Psychic- A target damaged by your eldritch blast has its mind clouded and suffers a 1d4 penalty to attacks, checks, and saves until the beginning of your next turn.

Bludgeoning- A target damaged by your eldritch blast is crushed as if the victim of a rock slide and knocked prone.

Piercing- A target damaged by your eldritch blast is deeply wounded allowing its humours to mix in unnatural ways. It becomes poisoned until it regains at least 1 hit point.

Slashing- A target damaged by your eldritch blast is raked by conjured blades that destroy garments and slice sinews. It has disadvantage on attacks until the end of your next turn.

[JNAProductions]

Piercing- A target damaged by your eldritch blast is deeply wounded allowing its humours to mix in unnatural ways. It becomes poisoned until it regains at least 1 hit point.

That is either useless (Poison immune foes or the occasional regenerator) or way too good (Poisoned for the rest of the encounter, in all probability).