Call of Cthulhu (role-playing game) in the context of "Role-playing game"

A tabletop role-playing game (TTRPG or TRPG), also known as a pen-and-paper role-playing game, is a kind of role-playing game (RPG) in which the participants describe their characters' actions through speech and sometimes movements. Participants determine the actions of their characters based on their characterization, and the actions succeed or fail according to a set formal system of rules and guidelines, usually involving randomization (such as through dice). Within the rules, players have the freedom to improvise, and their choices shape the direction and outcome of the game.Neither pen and paper nor a table are strictly necessary for a game to count as a TTRPG; rather, the terms pen-and-paper and tabletop are typically used to distinguish this format of RPG from role-playing video games or live action role-playing games. Online play of TTRPGs through videoconferencing has become common since the COVID-19 pandemic.

Some common examples of tabletop role-playing games include Dungeons & Dragons, Call of Cthulhu, and Pathfinder.

Chaosium Inc. (/keɪˈɒsiəm/ kay-OSS-ee-əm) is a publisher of tabletop role-playing games established by Greg Stafford in 1975. Chaosium's major product lines include RuneQuest, set in Stafford's fictional world of Glorantha; Call of Cthulhu, based on the horror fiction stories of H. P. Lovecraft; Pendragon, based on Thomas Mallory's Le Morte d'Arthur; and 7th Sea, "swashbuckling and sorcery" set in a fantasy 17th-century Europe.

Many of Chaosium's product lines are based upon literary sources. Other notable game designers have written for Chaosium. These include David Conyers, Matthew Costello, Larry DiTillio, David A. Hargrave, Rob Heinsoo, Keith Herber, Jennell Jaquays, Katharine Kerr, Reiner Knizia, Charlie Krank, Robin Laws, Steve Perrin, Sandy Petersen, Ken Rolston, Ken St. Andre, Jonathan Tweet, John Wick, and Lynn Willis; among others.

Basic Role-Playing (BRP) is a tabletop role-playing game which originated in the RuneQuest fantasy role-playing game. Chaosium released the BRP standalone booklet in 1980 in the boxed set release of the second edition of RuneQuest. Greg Stafford and Lynn Willis are credited as the authors. Chaosium used the percentile skill-based system as the basis for most of their games, including Call of Cthulhu, Stormbringer, and Elfquest.

Carl Sanford Joslyn "Sandy" Petersen (born September 16, 1955) is an American game designer. He worked at Chaosium, contributing to the development of RuneQuest and creating the acclaimed and influential horror role-playing game Call of Cthulhu. He later joined id Software where he worked on the development of the Doom franchise and Quake. As part of Ensemble Studios, Petersen subsequently contributed to the Age of Empires franchise.