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Deep Magic: Pestilent Warlock Patron

Deep Magic: Pestilent Warlock Patron

In the spirit of Deep Magic, your arcane caster can now explore the putrid potential of vermin and plague with Pestilent Magic. This entry presents the Plaguebearer patron for warlocks, with abilities befitting a host of malign essence.

 These warlocks can infect their spells and heal themselves from poison. The bittersweet font is a magic item a pestilent warlock might use to spread affliction under the guise of healer.

The Plaguebearer

Your patron is the malignant essence of plagues and illness itself, a miasmic entity often invisible but ever-present and ready to strike. Its motivations are simple: to spread disease and corrupt the flesh, allowing the Plaguebearer to flourish.

You are one of its hosts, bearing the mission to test living things of their worthiness. The strong, like you, survive. The weak perish.

Beyond allowing pestilence to flourish and spread, your patron demands little of you, treating you as a favored host for the blighted energies it wreaks upon the world. The Plaguebearer entities are born and reborn amidst calamity, but may cloak themselves as plague demons like Nergal, Pazuzu, or Ruohtta, or form as semi-mindless, horrific swarms of rats or crows, or manifest as something like the Biblical White Rider of the Apocalypse itself.


The Plaguebearer lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Plaguebearer Expanded Spells

1st-level: detect poison and disease, ray of sickness
2nd-level: blindness/deafness, ray of enfeeblement
3rd-level: phantom steed, stinking cloud
4th-level: giant insect, greater invisibility
5th-level: contagion, insect plague


Starting at 1st level, your patron bestows its blessing of disease upon you. You have a disease, either chosen with GM approval or randomly determined, that cannot be cured without abandoning your warlock pact. You suffer no visible symptoms of this disease, and you are immune to any penalties, conditions, or damage it would cause. You manifest the disease’s superficial, non-visible symptoms, such as a cough or headaches, but these remain constant and do not worsen or hinder you. You may change your patron disease by spending 24 hours with a creature, body, or item infected with the new disease, at which point you manifest the symptoms of the new disease and none of the old.

You are not usually contagious, but you may choose to make yourself so by spending 10 minutes to bring your disease to the surface. If you do so, the visible, late-stage symptoms of the disease appear, though you continue to be unhindered by it. These symptoms fade and you regain your non-contagious status at the next dawn.

You are immune to other diseases, and automatically recognize your patron disease in creatures, bodies, or in an object by studying them for 1 minute.


Starting at 6th level, you can lace your spells with pestilent energy. When you cast a spell requiring a spell attack, you can choose to make it an infected spell as a bonus action. An infected spell resolves the spell’s normal effects, and then requires the target to succeed at a Constitution saving throw or become infected by your patron disease and suffer immediate onset of symptoms. The target continues to make a Constitution saving throw at the end of each of its turns. After failing three of these saving throws, the disease’s effects last for its normal duration, or 7 days, whichever is longer, and the creature stops making these saves. After succeeding on three of these saving throws, the creature recovers from the disease’s effects. 

Once you’ve successfully infected a target with this feature, you can’t use it again until you finish a short or long rest.


Starting at 10th level, you become immune to poison. Additionally, when you are successfully hit by an attack or spell that would inflict poison damage, you may use your reaction to heal that many points of damage instead.

Once you use this feature, you can’t use it again until you finish a short or long rest.


Starting at 14th level, when you are reduced to 0 hit points, a noxious miasmic cloud erupts out of your body and swirls around you, manifesting spectral, skeletal rats and crows within it. This whirlwind attacks anything nearby, spreading poison and disease. At the beginning of each of your turns, each creature within 10 feet of your body must make a Dexterity saving throw. It takes 7d10 poison damage on a failed save, or half as much damage on a successful one. Any creature struck by the whirlwind must make a Constitution saving throw or become infected by your patron disease (as Infected Magic) and have disadvantage on all subsequent saving throws to shake off the disease. The whirlwind evaporates after you are healed to at least 1 hit point, or you die as a result of failing your final death save or taking damage equal to your hit point maximum.

Once you use this feature, you can’t use it again until you finish a long rest.

New Magic Item

This basin allows its bearer to transport a disease in its filth.

Bittersweet Font

Wondrous Item, Very Rare

By filling this shallow metal basin with clean water and speaking the command word, you allow any diseased creature (including yourself) who drinks from it to receive the benefits of a heal spell. After this healing, any water remaining in the font—or poured into it—becomes brackish and foul.

Speaking the command word again and drinking from the font infects the drinker with the last disease it cured, requiring a successful DC 17 Constitution save to resist. Once the font has successfully passed on its infection three times, the water clears, and can be used again for its healing properties.


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