Sandy Petersen’s Cthulhu Mythos

The Ultimate Guide to the Cthulhu Mythos in Roleplaying

Sandy Petersen’s Cthulhu Mythos is the most comprehensive guide to including Lovecraftian elements in your Roleplaying game, written by the author of the groundbreaking Call of Cthulhu role-playing game, and developed primarily by James Jacobs (creative director of Paizo) and David N. Ross.

This massive tome contains over 100 monster stat blocks, dozens of which are Cthulhu Mythos monsters that have never been described for Pathfinder or Dungeons and Dragons 5e – including new rules for interacting with 25 different Great Old Ones and Outer Gods (they are much more than a simple encounter!).

This is much more than a mere bestiary, however. Inside you will find new rules for Insanity and Dreams; 40 new spells and 30 Rituals – a new magic ruleset; dozens of mythos items and artifacts; dozens of Mythos cults detailed; and four new player races from Lovecraft’s universe – Dreamlands Cats, Mythos Ghouls, Gnorri, and Zoogs – as well as new character options, professions, feats, and race options for them.

Pathfinder Edition

The Pathfinder edition is a massive 512 pages and was released in 2018. Nearly sold out, the reprinting was begun in Fall 2018 with major changes to the art for each stat block. The first edition included photographs of professionally painted miniatures for each stat block. The reprint, by contrast, contains full color illustrations for each! The content is otherwise identical.

5e Fantasy Edition

In October we are launching a Kickstarter for the new edition of the book to be compatible with 5e fantasy. This is not merely a conversion from the Pathfinder edition, but rather a reimagining. It also contains new features, including:

Over 70 new illustrations not seen in the Pathfinder edition!
A new avatar of Nyarlathotep, the Dark Demon, as well as more former-human horrors
Dozens more monsters
Two new backgrounds (cultist and visionary)
More Dreamlands denizens
New character options
And more!

The 5e Fantasy edition is already written, edited, illustrated, and laid out. We are in the final proofreading stages. Because of this, it will go to print immediately after the Kickstarter campaign is funded!

Non-English Editions

Sandy Petersen's Cthulhu Mythos for 5e is now available in German and Italian. To see more details, please click the links below. The book is also planned to be published in French and Spanish in late 2019.

Dark Eye Edition coming 2019!

Our friends at Ulisses reached out to us last year requesting to convert the book for their Dark Eye roleplaying game. They are in the process of developing it now, for both their German and English editions!





“If you are a fan of horror or interjecting Lovecraftian horrors into your fantasy games, I think that you will really want a copy of Sandy Petersen’s Cthulhu Mythos on your shelves.”

— Christopher Helton

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Talking About Games

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“This is one of those books that you will read perhaps 20 pages, and you will feel as if only a couple of minutes passed…Everything is very well written and explained…The illustrations are perfect…notes, by Sandy Petersen himself…A very smooth process to learn how you can implement all of this mythos related information into your Pathfinder roleplaying game….Horror into a high fantasy environment….Overall my highest recommendation for Sandy Petersen’s Cthulhu Mythos. You need to get this book!…A bridge between the Call of Cthulhu Roleplaying game…Lovecraft stories, and the pathfinder roleplaying game…The alien beauty of the cthulhy mythos…dark splendour…dread and insanity…”

— Abraham

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Drive Thru RPG


“Put simply, this book is the best Mythos-themed product for Pathfinder. Period. If you want Cthulhu, or anything related to Cthulhu, this is the book to get.”

— James E.

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“People who are fans of both Cthulhu and Pathfinder will find a lot to love in Sandy Petersen’s Cthulhu Mythos for Pathfinder. Petersen and his team clearly thought through every aspect of the mythos and how it would change in heroic fantasy like Pathfinder. If you’re interested in bringing horror to your Pathfinder game, Sandy Petersen’s Cthulhu Mythos for Pathfinder is well worth the look. It might become your favorite.”

— Beth Rimmels

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