The players take the roles of ordinary people drawn into the realm of the mysterious: detectives, criminals, scholars, artists, war veterans, etc.

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.

After the death of Willis, Mike Mason became Call of Cthulhu line editor in 2013, continuing its development with Paul Fricker.

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.

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.

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, increasing the sense of immersion.

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.

On May 28, 2013, a crowdfunding campaign on Kickstarter for the 7th edition of Call of Cthulhu was launched with a goal of $40,000; it ended on June 29 of the same year having collected $561,836.

[5][15] Problems and delays fulfilling the Kickstarters for the 7th edition of Call of Cthulhu led Greg Stafford and Sandy Petersen (who had both left in 1998) to return to an active role at Chaosium in June 2015.

[30] The available milieux were also expanded with the release of Cthulhu Through the Ages, a supplement containing additional rules needed for playing within the Roman Empire, Mythic Iceland, a futuristic micro-setting, and the End Times, where the monsters of the mythos attempt to subjugate or destroy the world.

Chaosium has licensed other publishers to create supplements, video, card and board games using the setting and the Call of Cthulhu brand.

Many, such as Delta Green by Pagan Publishing and Arkham Horror by Fantasy Flight, have moved away completely from Call 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.

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

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

Arc Dream Publishing released a new version of Delta Green in 2016 as a standalone game, partially using the mechanics from Call of Cthulhu.

It bears mention because its eventual failure brought the company to hard times that affected its ability to produce material for Call of Cthulhu.

The first licensed Call of Cthulhu 25-millimetre (1.0-inch) gaming miniatures were sculpted by Andrew Chernack and released by Grenadier Models in boxed sets and blister packs in 1983.

In 2020 Chaosium announced a license agreement with Ardacious for Call of Cthulhu virtual miniatures to be released on their augmented reality app Ardent Roleplay.

A licensed[38] 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.

[44] Call of Cthulhu is a survival horror role-playing video game developed by Cyanide and published by Focus Home Interactive for PlayStation 4, Xbox One and Windows.

The game features a semi-open world environment and incorporates themes of Lovecraftian and psychological horror into a story which includes elements of investigation and stealth.

"[55] In a reader poll conducted by UK magazine Arcane in 1996 to determine the 50 most popular roleplaying games of all time, Call of Cthulhu was ranked 1st.

Editor Paul Pettengale commented: "Call of Cthulhu is fully deserved of the title as the most popular roleplaying system ever - it's a game that doesn't age, is eminently playable, and which hangs together perfectly.

[61] In his 2023 book Monsters, Aliens, and Holes in the Ground, RPG historian Stu Horvath noted up to this point in time, "roleplaying games are united in one way: In some fashion, they are all power fantasies.

Characters go someplace, kill some things, find some loot, and maybe gain enough experience points to unlock their hidden personal potential in the form of new spells or a new power."

The slumbering god is certainly one of the strangest of pop culture canonizations, but there seems to be an endless appetite — and deep wallets — for all things Cthulhu.