Expanded Cantrip Invocations
Ever got tired of warlocks relying on Eldritch Blast as their only damage dealing cantrip? The following invocations are designed to give other warlock cantrips the same treatment as Eldritch Blast, allowing each of them to do something unique, and hopefully stand as interesting alternatives to Eldritch Blast.
Even with these invocations, Eldritch Blast stands as the most potent cantrip for dealing damage with the help of the Agonizing Blast invocation. This is by design - if you purely care about dealing damage, Eldritch Blast should still be your go-to cantrip, while the remaining cantrips offer other benefits.
Poison Spray
The following invocations are designed to make poison spray a high damage crowd controlling tool:
Enfeebling Poison
Prerequisite: Poison Spray cantrip
Whenever a creature fails its save against your Poison Spray, it becomes poisoned until the end of your next turn.
Cloud of Poison
Prerequisite: Poison Spray cantrip
When you cast Poison Spray, you can choose two creatures within range that are within 5 feet of each other. Both creatures are affected by the spell.
Chill Touch
With the following invocations, Chill Touch becomes its own necromancer-like playstyle without becoming too much of a headache for the GM.
Essence Drain
Prerequisite: Chill Touch cantrip
When you deal damage to a creature with Chill Touch, you gain temporary hit points equal to half the amount of damage you dealt. These temporary hit points last for 1 minute.
Corpse Puppet
Prerequisite: 5th level, Chill Touch cantrip
If a beast or humanoid that is small or medium dies while the spectral hand from your Chill Touch cantrip clings to it, you can use your reaction to animate it, causing it to stand up immediately with 1 hit point. The creature uses zombie statistics. It remains animate for 1 hour, after which it collapses and dies.
In combat, the zombie's turn is immediately after yours, and it obeys your mental commands. You can only raise a maximum of one zombie at once this way, plus a number of additional zombies at higher levels: two zombies at 11th level, and three zombies at 17th level.
Infestation
This cantrip needs a significant buff to be able to compete with Eldritch Blast. Therefore, it gets three very powerful invocations:
Hungry Swarm
Prerequisite: Infestation cantrip
Each time a creature fails a save against your Infestation cantrip, the target takes an additional 1d6 piercing damage. The damage increases by one die when you reach 5th level (2d6), 11th level (3d6), and 17th level (4d6).
Hold on, isn't doubling the spell's damage a bit op? Not really, if you compare it to Eldritch Blast with the Agonizing Blast invocation. Assuming a Charisma of 16, it's 7 (2d6) damage versus 8 (1d10+3) damage. And that's not even considering the Hex spell, which is incompatible with Infestation.
Persistent Swarm
Prerequisite: Infestation cantrip
The duration of your Infestation cantrip changes to Concentration, up to 1 minute. If the target fails its saving throw against Infestation, the swarm clings to it. On each subsequent turn, you can use your action to cause the target to be affected by Infestation again as if it had failed its saving throw against the spell. The spell ends if you use your action for anything else. The spell also ends if the target is ever outside the spell's range or if it has total cover from you.
Directing Swarm
Prerequisite: Infestation cantrip
Whenever a creature fails its saving throw against your Infestation cantrip, instead of moving randomly, you can force the creature to move up to half its speed in a direction you designate. The movement doesn't provoke opportunity attacks.
Lightning Lure
Rather than competing with Grasp of Hadar, these invocations focus on making lighting lure something unique.
Electric Disarm
Prerequisite: Lightning Lure cantrip
When a creature fails its saving throw against your Lightning Lure cantrip, instead of pulling the target closer, you cause the target to take the spell's damage and then force it to drop one item of your choice it is holding. You can then pull the item into your space where you can catch it if you have a free hand, otherwise it drops at your feet.
Toppling Lightning
Prerequisite: Lightning Lure cantrip
If a creature fails its saving throw against your Lighting Lure cantrip, you have advantage on attack rolls against the creature until the end of your next turn. In addition, the creature cannot take reactions during this time.
Since Lightning Lure pulls enemies to you, its invocations were designed to be especially appealing to warlocks who like to engage in melee. First use lightning lure to put your enemy in a bad spot, then follow up with a powerful melee attack.
Frostbite
If you pick Frostbite as your spell of choice, chances are that you like to debuff enemies. The following invocations are designed to make the spell both better at debuffing as well as a bit more reliable, given Constitution is a good saving throw on many monsters:
Burst of Frost
Prerequisite: Frostbite cantrip
When you cast Frostbite, you can choose two creatures within range that are within 5 feet of each other. Both creatures are affected by the spell.
Chilling Cold
Prerequisite: Frostbite cantrip
When a creature succeeds it saving throw against your Frostbite cantrip, the creature takes half the cantrip's damage but suffers no additional effect from the cantrip.
Additionally, if a creature fails its saving throw against your Frostbite, it cannot use the Disengage action until the end of its next turn.
Toll the Dead
This is already a very solid damage dealing cantrip, so the focus is on making it mechanically different to Eldritch Blast instead:
Marked for Death
Prerequisite: Toll the Dead cantrip
If a creature fails its saving throw against your Toll the Dead cantrip, the creature becomes marked for death. The next time the creature takes damage before the end of your next turn, the creature takes 1d6 necrotic damage. This damage increases by one die when you reach 5th level (2d6), 11th level (3d6), and 17th level (4d6).
Grasp of the Grave
Prerequisite: Toll the Dead cantrip
An undead creature that fails its save against your Toll the Dead cantrip is frightened of you until the end of your next turn.
Magic Stone
There's no point trying to make this spell compete with Eldritch Blast, so instead these invocations aim to make it fill its own niche:
Hail of Stones
Prerequisite: Magic Stone cantrip
After casting Magic Stone, you can use a bonus action on subsequent turns to throw or hurl one of the stones imbued by the spell. In addition, you can imbue an additional stone with this spell when you reach 5th level (4 stones), 11th level (5 stones), and 17th level (6 stones).
Forceful Throws
Prerequisite: Magic Stone cantrip
Whenever a magic stone created by your Magic Stone cantrip misses its target, the stone keeps flying in a straight line, up to its maximum range. If another creature is in the stone's path, you can make an additional attack roll against that creature. On a success, that creature takes damage from the attack and the stone stops moving.
Sword Burst
This spell is already pretty good at what it does, but here is one invocation to make it a bit more versatile:
Blur of Swords
Prerequisite: Sword Burst cantrip
When you use Sword Burst, you don't provoke opportunity attacks from all creatures within range for the rest of your turn, no matter if those creatures succeeded on their saving throws or not.
Other Cantrips
This document doesn't aim to cover all the cantrips the warlock gets, but rather give ideas on how invocations of this style could look like. Invocations are an incredibly versatile feature and easy to homebrew. So, if you have a warlock in your group who wants to try to replace or supplement Eldritch Blast with another cantrip, go give some of these invocations a try, or work together with the warlock player to invent your own invocations exclusive to that specific warlock character.