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 Sandy Petersen, the author of the groundbreaking Call of Cthulhu role-playing game, and developed primarily by James Jacobs 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 Dungeons and Dragons 5e or Pathfinder – 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.

5e Fantasy Edition

The 5e Fantasy edition is well over 400 pages long, and available as PDF, hardcover and collectors edition bound in genuine leather. It is not merely a conversion from our 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!

Download and print the FREE Cthulhu Mythos 5e Fantasy Character Sheets for your game!

Non-English Editions

Sandy Petersen's Cthulhu Mythos for 5e is now available in German, French, Spanish and Italian. To see more details, please click the links below.

Pathfinder Edition

The Pathfinder edition is a massive 512 pages and was released in 2018. A Pathfinder second edition version is written, and undergoing editing, illustration, and layout. It is expected in 2020.

Dark Eye Edition
Now Available!

Awards

Reviews

Beyond The Veil

WRITTEN REVIEW

[In The Big Sleep] There’s plenty of rich political and spiritual drama for a talented DM to weave into the fabric of an exciting escapade, all while anticipating the inevitable appearance of eldritch horrors.

—Benjamin Page, Go Beyond the Veil

READ TO THE FULL REVIEW

Shut Up Nerd Podcast

PODCAST REVIEW

Dice Chukr - Ep. 01 -- Strangers and Rumors
Join our adventurers; Chad, Jacob, Josh, and Seth as DM Travis takes them through the maddening adventure!

Shut Up Nerd Podcast

LISTEN TO THE PODCAST

GeekNative

WRITTEN REVIEW

"I much enjoyed reading and planning to run Dark Worlds: The Ritual. This is my cup of unearthly tea. "

— Andrew Girdwood,

Read The Review

GeekDad

WRITTEN REVIEW

"...I have rarely received a review item that is so much in my wheelhouse as Ghoul Island. The marriage of the Cthulhu Mythos with my 5E campaign or Pathfinder is like manna from heaven for me. The fact that Sandy Peterson is the person behind this makes it even more appealing."

Read The Review

A Pawn's Perspective

WRITTEN REVIEW

"Ghoul Island offers a fresh, horrifying adventure that will tax even experienced players, pushing their characters to the brink of insanity...and sometimes over the edge."

— Rob Kalajian

Read The Review

Board Game Quest

WRITTEN REVIEW

"As a DM I like the excellent plot hooks and flexible options that Ghoul Island offers...I can't wait to have my DnD group play Ghoul Island""

— Brian Winters

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ENWorld

WRITTEN REVIEW

“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

VIDEO REVIEW

“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

Watch The Review

Drive Thru RPG

WRITTEN REVIEW

“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.

Read The Review

ENWorld

WRITTEN REVIEW

“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

Read The Review

Cthulhu Mythos News

The Prey June 28, 2021
A Study in Wickedness May 13, 2021
What the Hills Hide April 20, 2021
Diggin’ Deep March 23, 2021
Mini Offer of the Month March 16, 2021
The Turned Tide March 11, 2021
They Dreamed in Yellow February 24, 2021
Mini Offer of the Month February 22, 2021
The House by the Lake February 17, 2021
Not a Xorn January 27, 2021
Mini Offer of the Month January 11, 2021
Mini Offer of the Month December 15, 2020
Meanwhile in Resante… December 13, 2020
The Night is Dark & Young November 20, 2020
Famous Last Words Wanted! November 19, 2020
Night of the Brine November 12, 2020
Mini Offer of the Month November 10, 2020
The Night is Dark & Young October 23, 2020
An Omen in the Stars October 16, 2020
Free Keyless Map Downloads October 13, 2020
Famous Last Words Wanted! October 7, 2020
Mini Offer of the Month October 6, 2020
More Horror with Ghoul Island September 26, 2020
The Pale Shepherd September 17, 2020
Famous Last Words Wanted! September 9, 2020
Ready for Dark Worlds? September 6, 2020
Gaming Practicum Video March 17, 2020
Matt Corley February 26, 2020
Yig Snake Grandaddy February 22, 2020
Yig Snake Grandaddy February 17, 2020
Jonah Bomgaars February 17, 2020
Shout Out to Matt Corley February 5, 2020
More Anatomical Concepts November 10, 2019
More Anatomical Drawings September 19, 2019
Final Opportunity September 9, 2019
Any Anatomy Buffs Out There? September 7, 2019

General Downloads

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What the Hills Hide 1.37 MB 26 downloads

by Joshua Jarman A Cthulhu...
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A Study in Wickedness 1.37 MB 20 downloads

by Cameron Blair A Cthulhu...
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The Prey 1.37 MB 19 downloads

by G.J. Haines A Cthulhu...
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A King's Foresight (part 2) 1.37 MB 21 downloads

by Mark Ferguson From...
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A King's Foresight (part 1) 1.37 MB 21 downloads

by Mark Ferguson King’s Foresight is...
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The Pale Shepard 1.37 MB 20 downloads

by Simion Goudreault The Pale Shepherd is...
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The Curious Case of Doctor Argolias 2.34 MB 19 downloads

by Jonah Bomgaars The...
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Have You Found It Act 4 Keyless Maps 686.87 KB 38 downloads

Some folks have asked...
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Have You Found It Act 3 Keyless Maps 686.87 KB 37 downloads

Some folks have asked...
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Have You Found It Act 2 Keyless Maps 686.87 KB 39 downloads

Some folks have asked...

Cthulhu Mythos Sagas

Sandy Petersen, the mind that created the horror RPG genre, brings the Cthulhu Mythos to heroic adventure campaigns for 5e. The Cthulhu Mythos Sagas are full campaigns, taking your adventurers from level 1 to level 14 or 15. They are standalone but can easily be introduced into any fantasy setting.

SUBSCRIPTION MODEL ENDING SOON

Have You Found it Act 4 is now available for $25 and ships for free. Though the subscription model is ending, membership benefits, including the 10% sitewide discount on RPG products, will remain active through September 3, 2021.

Beginning September 4, 2021, each 4 act saga will be printed as a single volume at a significant discount. Shipping will no longer be free, but your overall savings will be substantial. Saga VI – Skin Deep, will be available for pre-order starting September 1st, 2021 and will ship in November 2021. As always, FREE PDFs will be available for download immediately upon purchase.

Subscription Benefits

  • Subscription/Membership benefits will end on 9/3/2021
  • Each book is priced at $25 and will ship for free. 
  • Free PDF of monthly Campaign Act available immediately upon purchase
  • Each title delivered 1 month prior to general retail release
  • 10% Discount on all roleplaying miniatures
  • 10% Discount on all roleplaying products (including the upcoming 4 act volume of Saga VI: Skin Deep)
  • Exclusive subscriber discounts and products offered periodically
  • Your subscription includes FREE Cthulhu Mythos character sheets
  • Month-to-month subscription, cancel at any time

Enter Have You Found It? after the exciting conclusion of The Big Sleep!

The next four sagas in your adventure series is NOW AVAILABLE!

In Act 1: The Jitters, a cursed play from an infamous playwright sows disaster wherever it appears. It has surfaced in the ancient city of Tiarazan to spread its malignant influence like the plague. Enemies seen and unseen oppose the characters and seek to forever change Tiarazan.

75+ full color pages in hardcover of Cosmic Horror!

In Act 2: Stage Rehearsal, it began with murder most foul. Two families of prestige, power, and influence. A shadowy group of zealots and an addled troupe of entertainers. At the center of it all, a masked figure intent on bringing a forbidden play, The King in Yellow, to the city of Tiarazan. As the play’s influence spreads, waves of madness and violence wash over the populace, leaving streets slick with blood. The clock is ticking, and time runs short before dark and ancient powers answer the play’s eldritch summons.

In Act 3: Oratorio, despite their victory, the heroes’ reprieve is short-lived. The Yellow Sign, now emblazoned upon the moon, shines down upon Tiarazan and spreads the vile corruption of the King in Yellow. With each passing hour, the machinations of a young aristocrat threaten to topple the city and given time, threaten to bring the entire world to madness. Everything comes down to a race against time, a dangerous visit to a mansion trapped between worlds, and a journey to a murdered world to face the powerful messenger of a Great Old One.

In the fourth and final Act of Have You Found It, Encore, Tiarazan’s reprieve from the machinations of the King in Yellow proved short-lived, as their ultimate purpose became evident, they were the harbinger of an even more powerful, appalling, and unspeakable Great Old One. An intelligence older than the stars, nigh omnipotent and omnipresent, has taken notice of the intricate plots eating the city from the inside, and with its attention its presence is felt. Can the Heroes of Tiarazan stave off the return of the vilest of Great Old Ones and save the city one last time, and with it the world?

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Have You Found It? - Now Available

SUBSCRIBE NOW and get a 10% discount on all RPG products through 9/3/21!

PLEASE NOTE: Subscription model and membership benefits will end September 3, 2021

SUBSCRIPTION PRODUCT COMING SOON!

Each act, when purchased as a subscription, is priced at $25 and will ship for FREE.

PLEASE NOTE: Subscription model and membership benefits will end 9/3/21

Saga VI: Skin Deep will. be available for pre-order in a single volume at 50% off 8/24/21

Saga VI ~ Skin Deep

Available for PreOrder September 1, 2021

 

 

Saga VII ~ Coming January 2022!

Ghoul Island introduces the Cthulhu Mythos to your heroic fantasy campaign as only the mind that created the horror RPG genre can!  Ghoul Island is a full campaign, taking your adventurers from level 1 to level 14.  It will be published in four volumes, each a separate act.

The first act, Voyage to Farzeen, will take PCs from 1st level to 5th.  It begins with a mutiny and ends in the underground tunnels where our adventurers discover an ancient temple dedicated to a horror thought to have been vanquished long ago!  Ghoul Island can easily be introduced into any 5E fantasy campaign and setting!

Each act is 50+ full color pages in hardcover...

...with new monsters to fight...

...and new locations to explore!

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Ghoul Island - Available Now!

Ghoul Island “Essentials” Miniature Pack

Ghoul Island “Essentials” Miniature Pack

$57.52

In Yig Snake Granddaddy, the new Cthulhu Mythos for 5e campaign, evil serpent folk seek to bring back prehistoric times, complete with pterodactyls, dinosaurs, and other monstrous beings.

In Land Out of Time, the first act of four, your player characters adventure into the wilds of Yilan, a primeval wilderness infested with carnivorous slime molds, gigantic crocodiles, and other lost horrors. The heroes encounter an evil serpent wizard, who prepares for an evil ritual beyond belief.

Betrayed, marooned, and hunted by super-intelligent enemies, can the heroes even survive, yet alone prevail?

Yig Snake Granddaddy and the Cthulhu Mythos Saga Subscription debuted in May 2020.   Get the full set now with free shipping!

Each act is 75+ full color pages in hardcover...

...with new monsters to fight...

...and new locations to explore!

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Yig Snake Granddaddy - Now Available

Enter the Dark World after the exciting conclusion of Yig Snake Granddaddy!

The next four sagas in your adventure series is NOW AVAILABLE!

In Dark Worlds, the new Cthulhu Mythos for 5e campaign, You and your friends become unwitting pawns caught up in the blunders of a mad ruler. His insane attempt to curry favor with the dread Fungi from Yuggoth results in your being teleported across space to the nightmare world of Yuggoth. The ritual keeps you alive … for now. But how long will its effects last? Your only hope is to track down the wizard Mustafo who was transported along with you, and who knows the spell of return. Unfortunately, Mustafo has been taken by the Fungi for their dire purposes and your attempt to rescue him have drawn their attention …

75+ full color pages in hardcover of Cosmic Horror!

In Act 2: Nithon, you traverse the Radiation Wastes of Yuggoth, encounter creatures and hazards from nightmare as you seek the Forest and City of Nithon. Here lies the Green Pyramid of the Watcher. The Pyramid awakens before your eyes, and you must explore its fearsome depths. Meanwhile, you are in constant threat of being caught up in the battles raging between the Watcher and its spawn versus the Fungi war-cyborgs.

In Act 3: The Zepzeg Cycle, you are brought to Yuggoth’s moon Thog, where you learn of the existence of the Zepzeg – a spacefaring alien species in many ways the antithesis of the Mi-Go. Plus, you learn of a lost colony of gnorri here so far from your world. Can you reconcile the Zepzeg, the Gnorri, and your own goals? Negotiate with an antediluvian entity of enormous psychic power, assist the Gnorri and the Zepzeg to forge alliances to help you in the difficult strife ahead, and find the awesome grimoire detailing a weapon of unthinkable might.

In the fourth and final Act of Dark Worlds, The Green Pyramid, the time has come at last to take the fight to the dread Mi-Go; the Fungi from Yuggoth. Returning to Yuggoth, you find that the Fungi have not been idle in your absence. Can you overcome the Fungi’s might, even with your new allies and eldritch constructs? An epic sacrifice allows ingress to the Pyramid, and you are ultimately led into the Null dimension and confront a being of mindless destruction. The campaign ends by giving you a choice with repercussions that echo across the galaxy. 

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Dark Worlds - Now Available

Enter the Big Sleep after the exciting conclusion of Dark World!

The next four sagas in your adventure series is NOW AVAILABLE!

In Act 1: The Sleeper Rising, you and your fellow heroes are caught between the religious police and a cabal of hidden cultists. Recruited by the king of Axphain, you must begin to root out the cultists. You discover a network of tunnels converging on the Royal Place, which leads to high-stakes intrigue and investigation.

At the King’s masquerade ball, an eldritch horror is unleashed, and the ultimate abomination rises above the city! Yet, this is only the beginning – volume 1 of The Big Sleep – an entire campaign devoted to exploring the terrors and wonders of the Great Old One Tsathoggua – the Sleeper.

75+ full color pages in hardcover of Cosmic Horror!

In Act 2: The Doomed World, you and your allies have temporarily escaped some of the worst effects of Tsathoggua’s rising, but now the Great Old One walks the surface world. What do the Sleeper’s demented cultists seek? You follow a pilgrimage of cultists through a deadly forest, to an enchanted mountain, hollow within. From there you must penetrate and escape a fortress of sub-human bestial horrors.

Eventually your heroes enter the neighboring, not-yet-blighted Kingdom of Yetive. You rush to seek the Queen’s aid, but she has her own plans and goals, and you and your fellow heroes are not the only factions calling upon her.

In Act 3: The Fate of the Empire, you and your heroes now seek assistance from the mountain kingdom of Lorenz, but King Leo proves troublesome indeed. He demands your heroes lead an expedition to the cultists’ hollow mountain. Unfortunately, his secret dreams and weaknesses threaten your mission, and your heroes must flee on Pegasus-back in an exciting aerial chase against winged nightmares.

Your heroes make their way to the imperial capital, but the court is in turmoil. You have the unique opportunity to shape the empire’s response to the crisis. Can you organize and unify the empire? Can even the massed forces of humankind stave off the looming disaster? Or is all the world fated to end up in the gullet of the monstrous Sleeper – Tsathoggua himself.

In the fourth and final Act of Big Sleep, Lullaby, Tsathoggua’s rampage continues unchecked. Your heroes must delve deep into the caverns whence the Great Old One emerged. Here, you encounter ancient subterranean civilizations and primordial beasts. As you make your way to the lightless realm of N’Kai, Tsathoggua’s origin, you find terror, abomination, and stygian vaults. But somewhere in this nightmare realm is the secret behind the Sleeper’s power. Only you and your heroes have the skills to obtain it, and the knowledge to use it. But Tsathoggua is also aware and alert – will you be ready for the final showdown with the titan itself and its army of slithering monsters?

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The Big Sleep - Now Available