| Title | Code | Date | Publisher | System (Setting) |
|---|
 R'lyeh | | 2019 | Dan Verssen Games | Warfighter |
| R'lyeh Rises | DMD-KS05B | 2024 | CMON Limited | Cthulhu Cthulhu: Death May Die (Fear of the Unknown) |
| R'lyeh Rising | DMD-KS05 | 2019 | CMON Limited | Cthulhu: Death May Die |
| R'lyehian Seizures Promo | | 2023 | CMON Limited | Cthulhu: Death May Die (Fear of the Unknown) |
 R'lyehwatch | | 2023 | Third Chair Games | R'lyehwatch |
 R. L. McSterlingthong and Nikola Tesla vs. the Daughter of Skull-Face | NL063 | 2012 | NUELOW Games | ROLF! |
| Racial Insecurity | WDF22001 | 2013 | WildFire Games | CthulhuTech |
| Radio Killed Verna Starr | | Jul 2022 | Chaosium | Call of Cthulhu (Classic) |
| Radio Theatre Murder Mystery | | Sep 2021 | Chaosium | Call of Cthulhu (Classic) |
 Ragnarok | 45 | 2005 | SFSFW | Guns and Girls, Chain Reaction |
| The Raid | | Feb 2020 | Chaosium | Call of Cthulhu (Viking) |
| The Raid of Area 51 | | Oct 2019 | Chaosium | Call of Cthulhu (Now) |
| Raid on Alpha Base | | Jun 2023 | Self Published | Achtung! Cthulhu |
| Raid on Black Goat Wood * | | 2010 | Self Published | None |
 Raiders of R'lyeh * | | 2017 | Cipher Bureau | Raiders of R'lyeh |
| Raiders of R'lyeh Gamemaster's Guide and Complete Rules | | 2017 | Cipher Bureau | Raiders of R'lyeh |
| Raising Up | CHA0089 | 2004 | Chaosium | Call of Cthulhu (Now) |
| Ramblings of a Twisted Muse | CHA0314 | 2005 | Chaosium | Call of Cthulhu (Classic) |
| Ramsey Campbell Horrors Pack 1 | CW-RC1 | 2016 | Petersen Games | Cthulhu Wars |
| Ramsey Campbell Horrors Pack 2 | CW-RC2 | 2016 | Petersen Games | Cthulhu Wars |
| Randolph Carter College for Anime-Punk | | Aug 2020 | Chaosium | Call of Cthulhu (Classic) |
 The Rap Sheet | 1 | May 2009 | Pelgrane Press | Trail of Cthulhu |
| The Rap Sheet | 2 | May 2009 | Pelgrane Press | Trail of Cthulhu |
| The Rap Sheet | 3 | Aug 2009 | Pelgrane Press | Trail of Cthulhu |
| Rare Antiquities | | 2016 | Self Published | Lovecraftesque |
| The Rats in the Walls | | 2013 | Sphinx Speileverlag | The Rats in the Walls |
| The Ravenar Sagas | CHA0348 | 2008 | Chaosium | Call of Cthulhu (Dark Ages) |
| Ravenstone Sanitarium | CHA0350 | 2008 | Chaosium | Call of Cthulhu (Classic) |
| Ravishing Beauty | | Nov 2021 | Chaosium | Call of Cthulhu (Invictus) |
| Re-Animator 2508 | | Feb 2024 | Chaosium | Call of Cthulhu (Deep Space) |
| Re:Quest | 25 | Dec 1991 | RolePlaying Games SIG of America Mensa | Call of Cthulhu (Classic) |
| Read or Die * | | May 2020 | Fantasy Flight Games | Arkham Horror: The Card Game |
| The Reading of a Will | | Mar 2022 | Chaosium | Call of Cthulhu (Classic) |
| The Real Leeds | | 2017 | Self Published | Arkham Noir |
| Real Metal Token Frames | | Sep 2021 | Chaosium | Call of Cthulhu (Classic) |
| Realm of Cthulhu | | | Self Published | Talisman |
| The Realm of Shadows | PAG1006 | 1997 | Pagan Publishing | Call of Cthulhu (Classic) |
| The Realm of Shadows Player Aid Kit | RSPA | 1997 | Pagan Publishing | Call of Cthulhu (Classic) |
| Realms of Crawling Chaos | GBD1201 | 2011 | Goblinoid Games | Labyrinth Lord |
| Realms of Cthulhu | REB20001 | 2010 | Reality Blurs | Savage Worlds (Realms of Cthulhu) |
 Realms of Cthulhu Bennies * | | 2009 | Reality Blurs | Savage Worlds (Realms of Cthulhu) |
| Reanimator | | 2018 | Dynamite Entertainment | Reanimator |
| The Reanimator Returns | | Sep 2023 | Chaosium | Call of Cthulhu (Classic) |
| Recall of Cthulhu | | 2015 | Toy Vault | Recall of Cthulhu |
| Recipe for Obsession | | Sep 2023 | Chaosium | Call of Cthulhu (Classic) |
 Reckoning of the Dead | | | Self Published | Call of Cthulhu (WWII), Call of Cthulhu (Atomic), Call of Cthulhu (Classic), Call of Cthulhu (Gaslight), Call of Cthulhu (Now) |
| Recovered Relics | | 2009 | Self Published | Yellow Dawn |
| Recurrence | | 2019 | Adreama Games | Machina Arcana |
| Recurring Nightmares * | MAD21 | 2016 | Fantasy Flight Games | Mansions of Madness |
| Recursive Echoes * | AHB05 | 2020 | Fantasy Flight Games | Arkham Horror |
| Red Bat Cthulhu | | 2015 | Peryton Publishing | Red Bat |
| Red Desire | Cold Murder | | 2008 | Self Published | Yellow Dawn |
| Red Eye of Azathoth | REAz | 2011 | Kobold Quarterly | Call of Cthulhu (Strange Aeons) [1587AD], Call of Cthulhu (Dark Ages), Call of Cthulhu (Darker Trails) |
 Red Giant | 1 | 1990 | Folio Works | Call of Cthulhu (Classic) |
| Red Giant | 2 | 1990 | Folio Works | Call of Cthulhu (Classic) |
| Red in Tooth and Claw | cr5403 | Nov 2023 | Cthulhu Reborn | Cthulhu Eternal |
| The Red Mist | | 2016 | Pelgrane Press | Cthulhu Confidential |
| Red Skies | | Nov 2020 | Chaosium | Call of Cthulhu (WWI) |
| Red Spill in the Sea | | Apr 2021 | Chaosium | Call of Cthulhu (Gaslight) |
| Red Tide Rising | | 2021 | Fantasy Flight Games | Arkham Horror: The Card Game |
| A Red, Red Rose | | Aug 2022 | Chaosium | Call of Cthulhu (Now) |
| Redacted Rituals | | 2018 | Self Published | Delta Green |
| Referee Screen and Reference Sheets | ET005 | 2019 | Raven God Games | Eldritch Tales |
| Refractions of Glasston | | Dec 2019 | Taylor University Professional Writing | Call of Cthulhu (Classic) |
| Regency Cthulhu | CHA23177 | 2022 | Chaosium | Call of Cthulhu (Regency) |
| Reign of Cthulhu | ZMG71140 | 2016 | Z-Man Games | Pandemic |
| Reign of Terror | CHA23149 | 2017 | Chaosium | Call of Cthulhu (Strange Aeons) |
| Reliquaries Part 1 | | 2013 | Stardust Publications | Dark Aeons |
| Remains of the Deep | | Nov 2021 | Chaosium | Call of Cthulhu (Now) |
| The Rending Box | PELGT21 | 2011 | Pelgrane Press | Trail of Cthulhu |
| Renegade Tentacles of Doom | | 2023 | Modiphius Entertainment | Achtung! Cthulhu |
| The Repairer of Reputations | PELGT23 | 2011 | Pelgrane Press | Trail of Cthulhu |
| The Replicant | | 2015 | Stardust Publications | Dark Aeons |
| Research Assistant Promo Card | | Aug 2010 | Steve Jackson Games | Munchkin |
| A Resection of Time | CHA2364 | 1997 | Chaosium | Call of Cthulhu (Now) |
| Resident Evil * | | 2002 | Self Published | Call of Cthulhu (Now) |
| Residue of the Past | | Jan 2021 | Chaosium | Call of Cthulhu (Now) |
| Rest Stops | | 1996 | Self Published | Call of Cthulhu (Now) |
| Restitution | | Dec 2020 | Chaosium | Call of Cthulhu (Now) |
| Resurrection Men | MUH0580233 | 2023 | Modiphius Entertainment | Achtung! Cthulhu |
| Resurrection of the King | | 2016 | Mutant Chiron Games | Ressurection of the King |
| Resurrection Woods | | Nov 2021 | Chaosium | Call of Cthulhu (Now) |
| The Retreat | | Aug 2024 | Chaosium | Call of Cthulhu (Now) |
| The Return of Cyris Crane * | | 2017 | Skirmisher Publishing | Call of Cthulhu (Classic) |
| The Return of Doctor Moreau | | 2006 | Self Published | Call of Cthulhu (Classic) |
| Return of the Hound | | 2006 | ADP Systems | Call of Cthulhu (Classic) |
| Return of the Ripper | CHA0339 | 2007 | Chaosium | Call of Cthulhu (Gaslight) |
| Return to Dunwich | CHA2330 | 1991 | Chaosium | Call of Cthulhu (Classic) |
| Return to Lovecraft Country * | 0006 | 1997 | Triad Entertainments | Call of Cthulhu (Classic) |
| Return to Teutoberg Forest | | Jun 2022 | Chaosium | Call of Cthulhu (Invictus) |
| Return to the Dunwich Legacy * | AHC28 | 2018 | Fantasy Flight Games | Arkham Horror: The Card Game |
| Return to the Forgotten Age * | AHC46 | 2020 | Fantasy Flight Games | Arkham Horror: The Card Game |
| Return to the Island of Dr Moreau | | Aug 2019 | Chaosium | Call of Cthulhu (Classic) |
| Return to the Monolith | | 1998 | Self Published | Call of Cthulhu (Now) |
| Return to the Monolith * | | Mar 2018 | Chaosium | Call of Cthulhu (Classic) |
| Return to the Night of the Zealot * | AHC26 | 2018 | Fantasy Flight Games | Arkham Horror: The Card Game |
| Return to the Path of Carcosa * | AHC36 | 2019 | Fantasy Flight Games | Arkham Horror: The Card Game |
| Return to the Witch House | | 2022 | Stardust Publications | Dark Aeons |
| The Returned | | May 2022 | Chaosium | Call of Cthulhu (Classic) |
| The Reunion | | Jul 2020 | Chaosium | Call of Cthulhu (Classic) |
| Revealed Cult Secrets Promo Card | | Jun 2016 | Steve Jackson Games | Munchkin |
| Revelations of the Bacchae | GRR96401 | 2023 | Green Ronin Publishing | Cthulhu Awakens |
| The Revenant | | 2010 | Stardust Publications | Dark Aeons |
| Revenge of the Old Ones | | 2021 | SchilMil Games | AuZtralia |
| Reverberations | | 2017 | Arc Dream Publishing | Delta Green |
| Rhan-Tegoth | JCG032 | 2019 | Just Crunch Games | The Cthulhu Hack |
| Rhyme With Dark Reason | | 2004 | Self Published | Call of Cthulhu (Classic) |
| Rich Food | | Dec 2022 | Chaosium | Call of Cthulhu (Now) |
| Rich Man, Poor Man | | 2019 | Beyond Belief Games | Black Books |
| Ride a White Horse | | 2016 | Self Published | Lovecraftesque |
| Riding the Northbound | GGP1909 | 2019 | Golden Goblin Press | Call of Cthulhu (Classic) |
| Riot at Red Plank | GGP1803 | 2018 | Golden Goblin Press | Call of Cthulhu (Classic) |
| Ripper Fhtagn | | 2020 | Self Published | The Jack Hack |
| Ripples From Carcosa | CHA0312 | 2005 | Chaosium | Call of Cthulhu (End Time), Call of Cthulhu (Invictus), Call of Cthulhu (Dark Ages), Call of Cthulhu (Classic) |
| Ripples From Carcosa | CHA23134 | 2014 | Chaosium | Call of Cthulhu (Dark Ages), Call of Cthulhu (Classic), Call of Cthulhu (End Time), Call of Cthulhu (Invictus) |
| The Rise of Azathoth | | 2021 | Evil Hat Productions | Fate of Cthulhu |
| Rise of Cthulhu | | 2015 | Self Published | Rise of Cthulhu |
| The Rise of Hastur | | 2021 | Evil Hat Productions | Fate of Cthulhu |
| The Rise of the Basilisk | | 2021 | Evil Hat Productions | Fate of Cthulhu |
| Rise of the Black Sun | | | Modiphius Entertainment | Call of Cthulhu (Classic) |
| Rise of the Dead | CHA0355 | 2008 | Chaosium | Call of Cthulhu (Now) |
| Rise of the Dead - The Raid | CHA0393 | 2010 | Chaosium | Call of Cthulhu (Now) |
| Rise of the Elders | | 2017 | Self Published | Rise of the Elders |
| Rise of the Old Ones | | 2021 | Japanime Games | Kamigami Battles |
| The Rise of the Quiet | | 2021 | Evil Hat Productions | Fate of Cthulhu |
| The Rise of Tsathoggua | | 2024 | Spotless Dice Games | Fate of Cthulhu |
| The Rise of Yig | | 2021 | Evil Hat Productions | Fate of Cthulhu |
| The Rise of Yog-Sothoth | | 2021 | Evil Hat Productions | Fate of Cthulhu |
| Rising from the Stars | | Nov 2020 | Chaosium | Call of Cthulhu (Classic) |
| Rites of Cthulhu | | 2018 | Quirky Engine Entertainment | Rites of Cthulhu |
| Ritual | | 2022 | Ravenkeep Productions | Ritual |
| Ritual Pursuits * | | 2011 | Pelgrane Press | Trail of Cthulhu |
| Rituals of the Deep Ones | | 2015 | Necromancers of the Northwest | Pathfinder |
| Rituals of the Eternal Mother | | 2018 | Golden Goblin Press | Call of Cthulhu (Invictus) |
| RMS Titanic: The Millionaire's Special | PELGT28 | 2012 | Pelgrane Press | Trail of Cthulhu |
| The Road to Innsmouth * | HGE-AH01-EN | 2023 | Hourglass Escapes | Arkham Horror |
| Road to Lunacy | | Sep 2024 | Chaosium | Call of Cthulhu (Now) |
| The Road Unraveled | | Apr 2020 | Chaosium | Call of Cthulhu (Now) |
| The Roar in the Dark | | Sep 2021 | Chaosium | Call of Cthulhu (Strange Aeons) [Ancient China] |
| Roaring 20's Femme Fatale Generator | D10D-G018 | 2021 | D10 Dimensions | Call of Cthulhu (Classic) |
| Roaring 20's Speakeasy Generator | D10D-G017 | 2021 | D10 Dimensions | Call of Cthulhu (Classic) |
| Robo's Mythos CCG Web Page | | | Self Published | Mythos |
| The Rockdale Dead | | May 2022 | Chaosium | Call of Cthulhu (Classic) |
| The Rocky Vale Horror | | 2003 | Self Published | Call of Cthulhu (Now) |
| Rogue Handler * | DGR001 | 2021 | Parts Per Million | Rogue Handler |
| Rogue Handler Oracle Deck * | DGR002 | 2021 | Parts Per Million | Rogue Handler |
| Rogues Gallery | | 2009 | Self Published | Yellow Dawn |
| Role Player Independent | 1 | Dec 1992 | Symbiosis Publishing | Call of Cthulhu (Classic) |
| Role Player Independent | 10 | Sep 1993 | Symbiosis Publishing | Call of Cthulhu (Gaslight), Call of Cthulhu (Classic) |
| Role Player Independent | 12 | Nov 1993 | Symbiosis Publishing | Call of Cthulhu (Classic) |
| Role Player Independent | 13 | Dec 1993 | Symbiosis Publishing | Call of Cthulhu (Classic) |
| Role Player Independent | 2 | Jan 1993 | Symbiosis Publishing | Call of Cthulhu (Classic), Call of Cthulhu (Cyberpunk) |
| Role Player Independent | 3 | Feb 1993 | Symbiosis Publishing | Call of Cthulhu (Classic) |
| Role Player Independent | 4 | Mar 1993 | Symbiosis Publishing | Call of Cthulhu (Classic) |
| Role Player Independent | 5 | Apr 1993 | Symbiosis Publishing | Call of Cthulhu (Classic) |
| Role Player Independent | 7 | Jun 1993 | Symbiosis Publishing | Call of Cthulhu (Classic) |
| Role Player Independent | 14 | Feb 1994 | Symbiosis Publishing | Call of Cthulhu (Classic) |
| Roleplay, What, Who, Why and Where? | | | Self Published | Call of Cthulhu (Classic), GURPS (Horror) |
| Roleplayer | 22 | Nov 1990 | Steve Jackson Games | Call of Cthulhu (Classic), GURPS |
| Roll for Great Old Ones | | 2022 | Hodari Spiele | Roll for Great Old Ones |
| The Romanian Contract | | May 2021 | Chaosium | Call of Cthulhu (Now) |
| The Romanian Imperative | MUH052308 | 2021 | Modiphius Entertainment | Achtung! Cthulhu |
| The Ronin | | 2011 | Self Published | CthulhuTech |
| The Rookery | | Jan 2024 | Chaosium | Call of Cthulhu (Classic) |
| The Room with No Doors | | Dec 2020 | Chaosium | Call of Cthulhu (Classic) |
 Rosemary's Baby | | | Self Published | Mythos |
| Rough Magicks | PELGT09 | 2009 | Pelgrane Press | Trail of Cthulhu |
| Round6 | | Nov 2021 | Chaosium | Call of Cthulhu (Now) |
| Route 666: Three Strikes You're Out | | Apr 2021 | Chaosium | Call of Cthulhu (Atomic) |
| RPG Archive | | | Self Published | Call of Cthulhu (Strange Aeons) [1978], Call of Cthulhu (Dreamlands), Call of Cthulhu (Classic), Call of Cthulhu (Darker Trails), Call of Cthulhu (Now) |
| RPG Review | 1 | Sep 2008 | Self Published | Call of Cthulhu (Delta Green) |
| RPG Review | 7 | Mar 2009 | Self Published | Little Fears, Advanced Dungeons and Dragons (Ravenloft), GURPS, Call of Cthulhu (Classic), Vampyre the Masquerade, Kult, Chill, Trail of Cthulhu, Call of Cthulhu (Delta Green) |
| RPG Review | 13,14 | Dec 2011 | Self Published | Call of Cthulhu (Classic) |
| RPG Review | 17 | Sep 2012 | Self Published | Call of Cthulhu (Classic) |
| RPG Review | 18 | Dec 2012 | Self Published | Call of Cthulhu (Now), Call of Cthulhu (Classic) |
| RPG Review | 28.29 | Sep 2015 | Self Published | None |
| RPG Review | 43 | Jun 2019 | Self Published | Nephilim, Call of Cthulhu (Classic) |
| rpg.net | | | Self Published | Call of Cthulhu (Cyberpunk) |
| Ruins of Golgotha | | 2006 | ADP Systems | Call of Cthulhu (Classic) |
| Rumble in R'lyeh | | 2012 | Cryptozoic Entertainment | Penny Arcade: The Game |
| Runestone * | 5 | 1985 | Self Published | Call of Cthulhu (Classic) |
| Runestone * | 6 | 1985 | Self Published | Call of Cthulhu (Classic) |
| The Russians Are Coming!! | | Oct 2024 | Chaosium | Call of Cthulhu (Strange Aeons) [1961] |
| Rusty Cold | | Apr 2021 | Chaosium | Call of Cthulhu (Strange Aeons) |