A review copy of “The Malady Codex” was provided by the publisher. Find more DMs Guild Reviews on my website and YouTube channel.

Support my work via Patreon.

Designed by: Jason Bakos & Themis Paraskevas

dms guild reviewDisease and pestilence are as much a part of D&D as anything else, yet few would dare create an entire supplemental guide exploring new and virulent maladies. “The Malady Codex” features nearly a dozen diseases designed by medical students based on many real-world diseases, effectively applied to a fantasy universe.

The diseases are organized by their origins as Magical, Divine, or Natural. Each disease is divided up into an easy-to-read series of notes, including the disease’s Cause, Symptoms, and Cures.

Each disease is also given a potential plot hook for how to include it in a campaign. Some of these are well thought out, with original NPCs involved in the disease’s origins, such as the dragon Oxitorus the Choleric or the mold-spreading beholder Biathocax. Others are disappointingly vague and generic.

I appreciated that almost all the diseases are based on real-world, well-known diseases, whether historical or modern, such as the Bubonic Plauge, Mad Cow Disease, Cholera, Leprosy, and even a whole category of interracial STDs. The real world links establish an easy touchstone for understanding these afflictions and how they could work within a D&D universe.

dms guild review

Not all diseases are a pandemic. Many are actually non-lethal – but still a literal pain. The variety presented here helps provide an assortment of options depending upon how severe you want the disease to be – and whether or not that’s a focus of your storyline or merely a by-product.

Necrophorum, for example, could be an easy excuse for a low-level party to help out a farmer, or a farming village dealing with diseased animals. The Mindflayer Network and Demonic Virulence would be effective in campaigns that feature Mindflayers and Demons respectively (or both –  hello Out of the Abyss!), while the Mad Mage Virus could add an interesting twist to an encounter with enemy spellcasters.

The appendices at the end offer a nice little bonus of disease-themed NPCs as well as a few statblocks and magical items. I wish this were a bigger section. The parasitic Medtroid-like Malady is very cool and thematic and I would loved to see more creatures, either disease-ridden or literal walking maladies themselves.


  • 11 D&D-friendly diseases, organized by Origin, Symptoms, Cure, and potential Plot Hooks.
  • Many of the diseases are based on real-world counterparts, such as Tetanus, Cholera, and Leprosy.
  • Disease-healing abilities and spells are listed at the beginning.
  • An appendix with several NPCs, statblocks and magical items with a disease theme.


  • Mad Mage Virus is a neat idea but a  bit overly complicated.
  • Some of the plot hooks are just a few generic notes rather than specific stories.

The Verdict: With nearly a dozen diseases inspired from real-world maladies, “The Malady Codex” provides a variety of interesting and terrible afflictions to add to your campaign.

A review copy of “The Malady Codex” was provided by the publisher. Find more DMs Guild Reviews on my website and YouTube channel.

Support my work via Patreon.