Call of Cthulhu (role-playing game)

Call of Cthulhu is a horror tabletop role-playing game based on the Cthulhu Mythos of H. P. Lovecraft, first published by Chaosium in 1981. The game emphasizes investigation, psychological horror, and the fragility of human sanity when confronted with cosmic entities and forbidden knowledge. Players take on the roles of ordinary investigators— academics, journalists, detectives, and other everyday people—who gradually uncover terrifying secrets, encounter alien beings, and risk madness, death, or worse. Call of Cthulhu is renowned for its innovative sanity mechanics, its fidelity to the source literature, and its pervasive influence on both role-playing games and the broader presentation of Lovecraftian horror.

Overview

Set primarily in the 1920s, Call of Cthulhu draws directly from the stories of H. P. Lovecraft and the extended Cthulhu Mythos created by writers such as August Derleth. The game presents a world where humanity is utterly insignificant in the face of vast, indifferent cosmic powers. The core experience revolves around investigation: players gather clues, interrogate witnesses, delve into dusty libraries, and gradually piece together mysteries, all while struggling to maintain their mental equilibrium. Combat is often a last resort, as characters are physically fragile and the threats they face are frequently beyond direct confrontation. The game’s central mechanics are grounded in the Basic Role-Playing (BRP) system, which uses percentile dice to resolve skill tests and determine outcomes.

History

The origins of Call of Cthulhu trace back to the late 1970s, when Chaosium had already established itself with the fantasy game RuneQuest, which introduced the Basic Role-Playing engine. Designer Sandy Petersen, a devoted fan of Lovecraft’s work, proposed a horror game that would utilize the same system to portray ordinary people facing the unimaginable. The first edition of Call of Cthulhu was released in 1981 as a boxed set and was immediately recognized for its atmospheric approach and unique treatment of madness. A second edition followed in 1983, and a third edition in 1984 expanded the rules and incorporated a wealth of new material.

The fourth edition arrived in 1989 as a hardcover book, further refining the game and cementing its status as the definitive horror RPG of its time. A fifth edition was published in 1992, with a substantial revision released in 1998 often referred to as “5.6 edition”; this version remained in print for many years and served as the basis for a prolific line of supplements. The sixth edition, released in 2004 to mark the game’s twentieth anniversary, offered a reorganization and cleanup of the rules but preserved the core mechanics largely intact. In 2014, after a successful Kickstarter campaign, Chaosium released the seventh edition, a comprehensive redesign by Paul Fricker and Mike Mason. This edition introduced several modernizations, such as bonus and penalty dice, pushing rolls, an expanded luck system, and a fresh approach to character creation, while keeping the soul of the game intact. The seventh edition has become the current and most widely played version.

Game System

Call of Cthulhu uses a percentile-based skill system derived from Basic Role-Playing. Characters are defined by a set of characteristics and a wide range of skills, and most actions are resolved by rolling a d100 and comparing the result to a target number. The core of the system is intuitive: if the roll is equal to or less than the relevant skill value, the action succeeds.

Characteristics include Strength, Constitution, Size, Dexterity, Appearance, Intelligence, Power, and Education. In earlier editions, these were typically generated with 3d6 or 2d6+6 rolls and expressed on a 3–18 scale, while skills were independently determined as percentile values. The seventh edition re-scaled characteristics to a percentile format by multiplying the original values by five, allowing both characteristics and skills to operate on the same scale and making the rules more transparent.

Skills represent capabilities such as Library Use, Spot Hidden, Fast Talk, Firearms, Dodge, and Cthulhu Mythos. Investigators begin with skill points allocated based on their profession and personal interests. The seventh edition introduced the option to “push” a failed roll: a player may describe how the character tries harder or takes a greater risk, and if the Keeper (game master) agrees, a second roll is allowed, but failure brings more severe consequences.

Sanity is the hallmark of Call of Cthulhu. Each investigator has a Sanity score, which starts equal to the character’s Power. Confronting horrific entities, witnessing unnatural events, or reading forbidden books forces a Sanity roll; failure results in loss of Sanity points. Loss of a significant amount of Sanity in a short period can cause temporary or indefinite insanity, forcing the character to adopt phobias, delusions, or other mental disorders. Learning the Cthulhu Mythos skill directly reduces the maximum possible Sanity, reflecting the corrosive effect of mythos knowledge. Once Sanity reaches zero, the investigator becomes permanently and irrevocably insane, removed from play.

Combat is intentionally lethal. Weapons deal realistic damage, and characters can sustain serious wounds with lasting consequences. The system encourages players to avoid unnecessary violence, as even a single gunshot or a fall can kill or cripple an investigator. There are no escalating hit points for experienced characters; survival depends on caution, planning, and, often, sheer luck.

Magic is powerful but dangerous. Spells usually require the expenditure of magic points and Sanity, and learning them from ancient tomes increases the Cthulhu Mythos skill at the cost of mental stability. This reinforces the central theme that knowledge brings both power and ruin.

Setting

The default setting for Call of Cthulhu is the world of the 1920s, commonly known as the “Classic Era.” This period sits at the intersection of modernity and superstition, with the Great War still fresh in memory and the Roaring Twenties pulsing in cities like New York, London, and Arkham, Massachusetts. Arkham, Miskatonic University, Dunwich, and the squalid back alleys of Innsmouth serve as iconic locales drawn directly from Lovecraft’s stories. The 1920s setting provides a familiar historical framework while allowing the intrusion of the utterly alien to feel especially disorienting.

Beyond the 1920s, official supplements have opened up numerous other eras. The 1890s Victorian era is explored in the “Cthulhu by Gaslight” line, offering gaslit streets, hansom cabs, and Victorian occult societies. The modern day was first prominently featured in the 1992 sourcebook “Delta Green,” which casts investigators as members of a secret government conspiracy fighting mythos threats, and which eventually became its own standalone game. Other settings include the Dark Ages, the Roman Empire, the far future, and the post-apocalyptic world of “End Times.” This flexibility across time periods has kept the game fresh and allowed Keepers to tailor horror to vastly different historical contexts.

Editions and Supplements

Over its four-decade lifespan, Call of Cthulhu has amassed one of the most extensive libraries of supplements in the role-playing industry. The core rulebook has been updated through seven major editions, with the most current being the seventh edition, which is published as two primary volumes: the Keeper Rulebook, containing the complete game rules, mythos lore, and monsters, and the Investigator Handbook, focused on character creation, equipment, and player-facing information.

Campaigns and scenarios are the heart of the game’s enduring popularity. Landmark works include Masks of Nyarlathotep, a globe-spanning epic widely considered one of the greatest RPG campaigns ever written; Horror on the Orient Express, a journey across 1920s Europe aboard the legendary train; Beyond the Mountains of Madness, a direct sequel to Lovecraft’s novella; and The Two-Headed Serpent, a Pulp Cthulhu campaign set in the 1930s. Countless shorter scenarios have been published, both by Chaosium and by third-party creators under license, creating a vast ecosystem of ready-to-play mysteries.

In addition to the traditional game, Chaosium released Pulp Cthulhu, an official supplement for the seventh edition that injects two-fisted action into the setting. Characters become more resilient, gain special talents, and can survive battles that would easily kill standard investigators, enabling a style of play closer to 1930s adventure serials while still retaining cosmic horror.

Related Games and Media

Call of Cthulhu has spawned several direct offshoots and influenced entire sub-genres of role-playing. The most notable is Delta Green, which began as a Call of Cthulhu supplement in 1992 and later evolved into an independent game system, winning numerous awards for its modern conspiracy-horror vision. Chaosium’s own Basic Role-Playing system, the framework from which Call of Cthulhu grew, was eventually released as a standalone generic system.

The game’s investigative focus also inspired the creation of other dedicated horror-investigation systems, most prominently Trail of Cthulhu by Pelgrane Press. Released in 2008, Trail of Cthulhu uses the GUMSHOE system to ensure that investigators never miss a core clue due to a failed die roll, directly addressing a known pain point in traditional CoC gameplay. The two games have coexisted peacefully, offering different interpretations of Lovecraftian mystery.

Beyond tabletop gaming, Call of Cthulhu has been adapted into multiple video games, including the 2018 survival horror title Call of Cthulhu developed by Cyanide Studio, and earlier titles such as Call of Cthulhu: Dark Corners of the Earth. The game’s themes and sanity mechanics have left a permanent mark on horror video games, from the Eternal Darkness series to Amnesia. A line of novels, short story collections, and audio dramas has further expanded the brand.

Reception and Awards

Call of Cthulhu has received consistent critical acclaim since its release. It won the Origins Award for Best Roleplaying Rules in 1982 and has accumulated multiple Origins and ENnie Awards over the decades for specific supplements and editions, with the seventh edition and its Keeper Rulebook winning Gold ENnies. The game was inducted into the Origins Hall of Fame in 1995, and its campaigns, particularly Masks of Nyarlathotep, are frequently cited among the greatest tabletop adventures ever published. Critics have praised the game for its atmosphere, its commitment to the source material, and the elegant simplicity with which the sanity system models psychological deterioration. The seventh edition’s modernizations have been warmly received, attracting new players while satisfying long-time fans.

Legacy

Call of Cthulhu fundamentally reshaped horror role-playing by shifting the focus from combat prowess to investigation and psychological survival. It demonstrated that a game could be terrifying without relying on gore or monsters alone, and that the slow erosion of a character’s mind could be as gripping as any sword fight. The sanity mechanic pioneered in these rules has become a standard trope in video games and tabletop design. Moreover, the game has served as a gateway into Lovecraft’s literary universe for generations of readers and gamers, solidifying the Cthulhu Mythos as a living, evolving mythology. After more than forty years, Call of Cthulhu remains in active play worldwide, supported by a passionate community, a steady stream of new content, and a system that continues to remind players that some secrets should never be uncovered.