Tabletop games Wargaming

Call of Cthulhu - role-playing game

Call of Cthulhu 1st edition box cover, 1981.
Illustration by Gene Day.
Publication date 1981
Genre(s) Horror
System(s) Basic Role-Playing (adaptations into other systems also available)

Call of Cthulhu is a horror fiction role-playing game based on H. P. Lovecraft's story of the same name and the associated Cthulhu Mythos. The game, often abbreviated as CoC, is published by Chaosium; it was first released in 1981 and is currently in its seventh edition, with many different versions released. It makes use of Chaosium's Basic Role-Playing (BRP) system, with special rules for Sanity.


The setting of Call of Cthulhu is a darker version of our world, based on H. P. Lovecraft's observation (from his essay, Supernatural Horror in Literature) that "The oldest and strongest emotion of mankind is fear, and the strongest kind of fear is fear of the unknown." The original game, first published in 1981, uses mechanics from Basic Role-Playing, and is set in the 1920s, the setting of many of Lovecraft's stories. Additional settings were developed in the 1890s Cthulhu by Gaslight supplement, a blend of occult and Holmesian mystery and mostly set in England, and modern/1980s conspiracy with Cthulhu Now. More recent additions include 1000 AD (Cthulhu: Dark Ages), 23rd century (Cthulhu Rising) and Ancient Roman times (Cthulhu Invictus). The protagonists may also travel to places that are not of this earth, represented in the Dreamlands (which can be accessed through dreams as well as being physically connected to the earth), to other planets, or into the voids of space.

Call of Cthulhu uses the Basic Role-Playing system used by other Chaosium games (first seen in RuneQuest). For as long as they stay functionally healthy and sane, characters grow and develop. Call of Cthulhu does not use levels, but is completely skill-based, with player characters getting better with their skills by succeeding at them. They do not, however, gain "hit points" and do not become significantly harder to kill.

Unlike Dungeons and Dragons, which typically uses a d20 to determine outcomes of particular decisions and events, Call of Cthulhu uses percentile dice (with a results ranging from 1 to 100) to determine such events. Every player statistic is intended to be compatible with the notion that there is a probability of success for a particular action given what the player is capable of doing. For example, an artist may have a 75% of being able to draw something (represented by having 75 in Art skill), and thus rolling a number under 75 would yield a success. Rolling 1/5 or less of the skill level (1-15 in our example) would be a "special success" (or an "impale" for combat skills) and would yield some extra bonus to be determined by the keeper. For example, the artist character might draw especially well or especially fast, or catch some unapparent detail in the drawing.

The players take the roles of ordinary people drawn into the realm of the mysterious: detectives, criminals, scholars, artists, war veterans, etc. Often, happenings begin innocently enough, until more and more of the workings behind the scenes are revealed. As the characters learn more of the true horrors of the world and the irrelevance of humanity, their sanity (represented by "Sanity Points", abbreviated SAN) inevitably withers away. The game includes a mechanism for determining how damaged a character's sanity is at any given point; encountering the horrific beings usually triggers a loss of SAN points. To gain the tools they need to defeat the horrors - mystic knowledge and magic - the characters may end up losing some of their sanity, though other means such as pure firepower or simply outsmarting one's opponents also exist. Call of Cthulhu has a reputation as a game in which it is quite common for a player character to die in gruesome circumstances or end up in a mental institution. Eventual triumph of the players is not assumed.


The original conception of Call of Cthulhu was Dark Worlds, a game commissioned by the publisher Chaosium but never published. Sandy Petersen, now best known for his work on the Doom computer game, contacted them regarding writing a supplement for their popular fantasy game RuneQuest set in Lovecraft's Dreamlands. He took over the writing of Call of Cthulhu, and the game was released in 1981, using a version of the Basic Role-Playing system used in RuneQuest.


Since Petersen's departure from Chaosium, continuing development of Call of Cthulhu passed to Lynn Willis, credited as co-author in the fifth and sixth editions, and more recently to Paul Fricker and Mike Mason. The game system underwent only minor rules changes in its first six editions (between 1981 and 2011); the current seventh edition, released 2014, includes more significant rules alterations than in any previous release.

Edition Published Format Notes
Call of Cthulhu 13 November 1981 Boxed set Includes 16-page Basic Role-Playing booklet in addition to main rulebook. First printing released in oversized (9.2-inch wide x 12.2-inch high x 2-inch deep) box; second printing released in 1-inch-deep box.
Call of Cthulhu Designer's Edition 1982 Boxed set Limited edition of 200 copies, signed and numbered by designer Sandy Petersen. Includes Shadows of Yog-Sothoth campaign book.
Call of Cthulhu Second Edition [US release] 1983 Boxed set Released in oversized 1-inch-deep box. Consolidates rules into a single rulebook; minor rules changes.
Call of Cthulhu Second Edition [UK release] 1983 Boxed set Games Workshop licensed release in A4-sized 2-inch-deep box. Consolidates rules into a single rulebook; minor rules changes.
Call of Cthulhu Third Edition [US release] 1986 Boxed set Released in oversized 1-inch-deep box. Divides rules into separate Investigator's Book and Keeper's Book booklets.
Call of Cthulhu Third Edition [UK release] 1986 Hardcover book Games Workshop licensed release. Includes content from Cthulhu Companion supplement.
Call of Cthulhu 4th Edition 1989 Perfect-bound softcover book Includes content from Cthulhu Companion and Fragments of Fear: The Second Cthulhu Companion supplements. First printing transposes two columns of text on p. 46; second printing corrects this error.
Call of Cthulhu 5th Edition March 1992 Perfect-bound softcover book First version to credit Lynn Willis as co-author.
Call of Cthulhu Edition 5.1 April 1993 Perfect-bound softcover book Revised and corrected version of 5th Edition; "Edition 5.1" designator appears on title page.
Call of Cthulhu Edition 5.1.1 September 1993 Hardcover book or perfect-bound softcover book Revised and corrected version of 5th Edition; "Edition 5.1.1" designator appears on title page. Limited edition of 1,000 hardcover copies released through Wizard's Attic.
Call of Cthulhu Edition 5.1.2 September 1994 Perfect-bound softcover book Revised and corrected version of 5th Edition; "Edition 5.1.2" designator appears on title page.
Call of Cthulhu Edition 5.2 December 1995 Perfect-bound softcover book Revised and corrected version of 5th Edition; "Edition 5.2" designator appears on title page.
Call of Cthulhu Edition 5.5 June 1998 Perfect-bound softcover book Reorganised and updated version of 5th Edition, with new cover art; "Edition 5.5" designator appears on title page.
Call of Cthulhu Edition 5.6 November 1999 Hardcover book Revised and corrected version of Edition 5.5; "Edition 5.6" designator appears on title page.
Call of Cthulhu Edition 5.6.1 June 2001 Hardcover book Revised and corrected version of Edition 5.5; "Edition 5.6.1" designator appears on title page.
Call of Cthulhu 20th Anniversary Edition 20 August 2001 Leather-bound hardcover book Limited edition bound in green leather, with red metallic star-shaped Elder Sign glyph on cover. Smythe-sewn binding. Essentially the same rules as Edition 5.6.1, but with new "ancient tome" layout, printed in sienna ink.
Call of Cthulhu 20th Anniversary Miskatonic University Library Edition 2001 Leather-bound hardcover book Limited edition of 300 individually-numbered copies. As the 20th Anniversary Edition, above, except with gold metallic Elder Sign on cover, "Miskatonic University Restricted Collection" library-plate sticker on front endpaper, and flyleaf with hand-written issue number, "Miskatonic University limited editions" logo and text, and signatures of Chaosium staff members Charlie Krank, Lynn Willis, Dustin Wright, and David Mitchell. Sold wrapped in brown paper and twine, addressed to "Dr. Henry Armitage c/o Miskatonic University".
Call of Cthulhu 20th Anniversary Contributor's Edition 2001 Leather-bound hardcover book Limited edition of 50 individually-named copies presented to "those people or companies important to the longevity of Chaosium" per included letter. As the 20th Anniversary Miskatonic University Library Edition, above, except with copper metallic Elder Sign on cover and name of Cthulhu Mythos creature hand-written on flyleaf in place of an issue number.
Call of Cthulhu 20th Anniversary 'Name' Edition 2001 Leather-bound hardcover book Limited edition of 10 bespoke-named copies. As per the 20th Anniversary Contributor's Edition, above, except with customer-specified name printed on flyleaf in place of an issue number; signed by Sandy Petersen in addition to Chaosium staff members.
Call of Cthulhu 20th Anniversary Gen Con 2002 Edition 2002 Leather-bound hardcover book Limited edition of 20 individually-numbered copies presented to publishers at Gen Con 2002. As 20th Anniversary Miskatonic University Library Edition, above, except without brown-paper wrapping and with issue number (e.g., "Twenty of Twenty"), "GenCon 2002 ed." title, and "Farewell Milwaukee" text printed on signed flyleaf (which also bears a Chaosium stamp).
Call of Cthulhu 20th Anniversary Origins 2002 Edition 2002 Leather-bound hardcover book Limited edition of 10 individually-numbered copies presented to publishers at Origins 2002. As 20th Anniversary Gen Con 2002 Edition, above, except with "Origins 2002 ed." title printed on signed and stamped flyleaf.
Call of Cthulhu 6th Edition March 2004 (hardcover), February 2005 (softcover) Hardcover book, perfect-bound softcover book, or electronic (PDF) file Same layout and content as 20th Anniversary Edition, but in black ink.
Call of Cthulhu 25th Anniversary Edition 2006 Hardcover book Limited edition with cover art from original 1981 boxed-set edition. Same layout and content as 6th Edition.
Call of Cthulhu Anniversary Edition 1981-2011 July 2011 Leather-bound hardcover book Limited edition bound in red-brown leather. Same layout and content as 6th Edition, but printed on heavier, glossier paper.
Call of Cthulhu 7th Edition 2014 Electronic (PDF, EPUB, MOBI, or PRC) file Rules significantly revised by Paul Fricker and Mike Mason. New layout and cover art. Print version slated for release in 2015.

Early releases

For those grounded in the RPG tradition, the very first release of Call of Cthulhu created a brand new framework for table-top gaming. Rather than the traditional format established by Dungeons & Dragons, which often involved the characters wandering through caves or tunnels and fighting different types of monsters, Sandy Petersen introduced the concept of the Onion Skin: Interlocking layers of information and nested clues that lead the Player Characters from seemingly minor investigations into a missing person to discovering mind-numbingly awful, global conspiracies to destroy the world. Unlike its predecessor games, CoC assumed that most investigators would not survive, alive or sane, and that the only safe way to deal with the vast majority of nasty things described in the rule books was to run away. A well-run CoC campaign should engender a sense of foreboding and inevitable doom in its players. The style and setting of the game, in a relatively modern time period, created an emphasis on real-life settings, character research, and thinking one's way around trouble.

The first book of Call of Cthulhu adventures was Shadows of Yog-Sothoth. In this work, the characters come upon a secret society's foul plot to destroy mankind, and pursue it first near to home and then in a series of exotic locations. This template was to be followed in many subsequent campaigns, including Fungi from Yuggoth (later known as Curse of Cthulhu and Day of the Beast), Spawn of Azathoth, and possibly the most highly acclaimed, Masks of Nyarlathotep. Many of these seem closer in tone to the pulp adventures of Indiana Jones than H. P. Lovecraft, but they are nonetheless beloved by many gamers.

Shadows of Yog-Sothoth is important not only because it represents the first published addition to the boxed first edition of Call of Cthulhu, but because its format defined a new way of approaching a campaign of linked RPG scenarios involving actual clues for the would-be detectives amongst the players to follow and link in order to uncover the dastardly plots afoot. Its format has been used by every other campaign-length Call of Cthulhu publication. The standard of CoC scenarios was well received by independent reviewers. The Asylum and Other Tales, a series of stand alone articles released in 1983, rated an overall 9/10 in Issue 47 of White Dwarf magazine.

The standard of the included 'clue' material varies from scenario to scenario, but reached its zenith in the original boxed versions of the Masks of Nyarlathotep and Horror on the Orient Express campaigns. Inside these one could find matchbooks and business cards apparently defaced by non-player characters, newspaper cuttings and (in the case of Orient Express) period passports to which players could attach their photographs, bringing a Live Action Role Playing feel to a tabletop game. Indeed, during the period that these supplements were produced, third party campaign publishers strove to emulate the quality of the additional materials, often offering separately-priced 'deluxe' clue packages for their campaigns.

Additional milieu were provided by Chaosium with the release of Dreamlands, a boxed supplement containing additional rules needed for playing within the Lovecraft Dreamlands, a large map and a scenario booklet, and Cthulhu By Gaslight, another boxed set which moved the action from the 1920s to the 1890s.

Supplement campaigns

Cthulhu Now

In 1987, Chaosium issued the supplement titled Cthulhu Now, a collection of rules, supplemental source materials and scenarios for playing Call of Cthulhu in the present day. This proved to be a very popular alternative milieu, so much so that much of the supplemental material is now included in the core rule book.

Delta Green

Pagan Publishing has released a series of supplements in a similar vein, by the name Delta Green, that is set in the 1990s (although later supplements add support for playing closer to the present day).

Lovecraft Country

Lovecraft Country was a line of supplements for Call of Cthulhu released in 1990. These supplements were overseen by Keith Herber and provided backgrounds and adventures set in Lovecraft's fictional towns of Arkham, Kingsport, Innsmouth, Dunwich, and their environs. The intent was to give investigators a common base, as well as to center the action on well-drawn characters with clear motivations.

Recent history

In the years since the collapse of the Mythos collectible card game (production ceased in 1997), the release of CoC books has been very sporadic with up to a year between releases. Chaosium struggled with near bankruptcy for many years before finally starting their upward climb again.

2005 was Chaosium's busiest year for many years with ten releases for the game. Chaosium took to marketing "monographs" - short books by individual writers with editing and layout provided out-of-house - directly to the consumer, allowing the company to gauge market response to possible new works. The range of times and places in which the horrors of the Mythos can be encountered was also expanded in late 2005 onwards with the addition of Cthulhu Dark Ages by Stéphane Gesbert, which gives a framework for playing games set in 11th century Europe, Secrets of Japan by Michael Dziesinski for gaming in modern day Japan, and Secrets of Kenya by David Conyers for gaming in interwar period Africa.

In July 2011, Chaosium announced it would re-release a 30th anniversary edition of the CoC 6th edition role-playing game. This 320-page book features thick (3 mm) leatherette hard-covers with the front cover and spine stamped with gold foil. The interior pages are printed in black ink, on 90 gsm matte art paper. The binding is thread sewn, square backed. Chaosium offered a one-time printing of this Collector's Edition.

In May 28, 2013, a kickstarter for the 7th Edition of Call of Cthulhu was launched, it ended in June 29 of the same year and collected $561,836.


Chaosium has licensed other publishers to create supplements using their rule system, notably including Delta Green by Pagan Publishing. Other licensees have included Miskatonic River Press, Theater of the Mind Enterprises, Triad Entertainment, Games Workshop, Fantasy Flight Games, RAFM, Grenadier Models Inc. and These supplements may be set in different time frames or even different game universes from the original game.

D20 Call of Cthulhu

In 2001, a stand-alone version of Call of Cthulhu was released by Wizards of the Coast, for the d20 system. Intended to preserve the feeling of the original game, the d20 conversion of the game rules were supposed to make the game more accessible to the large D&D player base. The d20 system also made it possible to use Dungeons & Dragons characters in Call of Cthulhu, as well as to introduce the Cthulhu Mythos into Dungeons & Dragons games. The d20 version of the game is no longer supported by Wizards as per their contract with Chaosium. Chaosium included d20 stats as an appendix in three releases (see Lovecraft Country), but have since dropped the "dual stat" idea.

Dark Corners of the Earth

A licensed first-person shooter adventure game by Headfirst Productions, based on Call of Cthulhu campaign Escape from Innsmouth and released by Bethesda Softworks in 2005/2006 for the PC and Xbox.

Trail of Cthulhu

In February 2008, Pelgrane Press published Trail of Cthulhu, a stand-alone game created by Kenneth Hite using the GUMSHOE System developed by Robin Laws. Trail of Cthulhu '​s system is more mystery oriented and focuses mostly on interpreting clues.

Shadows of Cthulhu

In September 2008, Reality Deviant Publications published Shadows of Cthulhu, a supplement that brings Lovecraftian gaming to Green Ronin's True20 system.

Realms of Cthulhu

In October 2009, Reality Blurs published Realms of Cthulhu, a supplement for Pinnacle Entertainment's Savage Worlds system.

The Laundry

In 2010, Cubicle 7 published an official role-playing game, The Laundry (2010, ISBN 1-907204-93-8, Gareth Hanrahan) and a number of supplements, all based on Charles Stross's "Bob Howard - Laundry" series.

The Wasted Land

In April 2011, Chaosium and new developer Red Wasp Design announced a joint project to produce a mobile video game based on the Call of Cthulhu RPG, entitled Call of Cthulhu: The Wasted Land. The game was released on 30 January 2012.

Card games

Read main articles: Mythos (card game) and Call of Cthulhu: The Card Game

Mythos was a collectible card game (CCG) based on the Cthulhu Mythos that Chaosium produced and marketed during the mid-1990s. While generally praised for its fast gameplay and unique mechanics, it ultimately failed to gain a very large market presence. It bears mention because its eventual failure brought the company to hard times that affected its ability to produce material for Call of Cthulhu. Call of Cthulhu: The Card Game is a second collectible card game, produced by Fantasy Flight Games.


The first licensed Call of Cthulhu 25mm gaming miniatures were sculpted by Andrew Chernack and released by Grenadier Models in boxed sets and blister packs in 1983. The license was later transferred to RAFM. As of 2011, RAFM still produce licensed Call of Cthulhu models sculpted by Bob Murch. Both lines include investigator player character models and the iconic monsters of the Cthulhu mythos. As of July 2015, Reaper Miniatures started its third "Bones Kickstarter", a Kickstarter intended to help the company migrate some miniatures from metal to plastic, and introducing some new ones. Among the stretch goals was the second 50$ expansion, devoted to the Mythos, with miniatures such as Cultists, Deep Ones, Mi'Go, and an extra 15$ Shub-Niggurath "miniature" (it is, at least, 6x4 squares). It is expected for those miniatures to remain in the Reaper Miniatures catalogue after the Kickstarter project finishes.


The game won several major awards in the following years:

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