| Tagmar | 1991 | — | Brazil |
| Taiga | — | — | Finland |
| Tales from the Floating Vagabond | 1991 | Avalon Hill | United States |
| Tales from the Loop | 10 March 2017 | Target Games | Sweden |
| Tales of Xadia: The Dragon Prince Roleplaying Game | 2021 | Fandom, Inc. | — |
| Talislanta | 1987 | Bard Games | United States |
| Te deum pour un massacre | 2005 | Matagot | France |
| Technoir | 2011 | — | — |
| Teenage Mutant Ninja Turtles & Other Strangeness | 1985 | Palladium Books | United States |
| Teenagers from Outer Space | 1987 | R. Talsorian Games | United States |
| Ten Candles | 2015 | — | — |
| Tenga | 2011 | Éditions John Doe / Chibi | France |
| Tenra War | 2007 | Enterbrain | Japan |
| Terra Incognita | 2001 | Grey Ghost Press | United States |
| Terra Primate | 2002 | Eden Studios, Inc. | United States |
| Terra the Gunslinger | 2001 | — | Japan |
| The Adventures of Indiana Jones Role-Playing Game | 1984 | TSR | United States |
| The Authority Role-Playing Game | 2004 | Guardians of Order | Canada |
| The Black Company | 2004 | Green Ronin Publishing | United States |
| The Black Hack | 2016 | — | — |
| The Burning Wheel | 2002 | The Burning Wheel | United States |
| The Castle Perilous | 1980 | — | — |
| The Classic Dungeons & Dragons Game | 1994 | TSR | United States |
| The Confederate Rangers | 1989 | — | — |
| The Court of the Empress | 2006 | self-published work | — |
| The Dark Eye | 1984 | Ulisses Spiele | Germany |
| The Doctor Who Role Playing Game | 1985 | FASA Corporation | United States |
| The Dominion Tank Police Role-Playing Game | 1999 | Guardians of Order | Canada |
| The Dresden Files Roleplaying Game | 2010 | Evil Hat Productions | United States |
| The Dying Earth Roleplaying Game | 2001 | Pelgrane Press | United States |
| The End | 1995 | — | — |
| The Esoterrorists | 2006 | Pelgrane Press | United States |
| The Esoterrorists 1st edition | 2006 | Pelgrane Press | United States |
| The Esoterrorists 2nd edition | 2013 | Pelgrane Press | United States |
| The Everlasting | 1997 | — | — |
| The Extraordinary Adventures of Baron Munchausen | 1998 | Hogshead Publishing | United Kingdom |
| The Face of Angels | 2007 | self-published work | — |
| The Fantasy Trip | 1977 | Metagaming Concepts | United States |
| The Farm | 2004 | Memento Mori Theatricks | United States |
| The Green Knight: A Fantasy Roleplaying Game | 2020 | — | — |
| The Judge Dredd Roleplaying Game | 2002 | Mongoose Publishing | United States |
| The Laundry | 2010 | Cubicle 7 | United Kingdom |
| The Legacy of Zorro | 2001 | Gold Rush Games | United States |
| The Lord of the Rings Roleplaying Game | 2002 | Decipher | United States |
| The Lost Universe | March 2024 | National Aeronautics and Space Administration | — |
| The Magical Land of Yeld | 2008 | — | — |
| The Masters of the Universe Role Playing Game | 1985 | FASA Corporation | United States |
| The Mechanoid Invasion | 1981 | Palladium Books | United States |
| The Mechanoids | 1985 | Palladium Books | United States |
| The Metabarons Roleplaying Game | 2001 | West End Games | United States |
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| The Mountain Witch | 2005 | — | — |
| The New Easy-to-Master Dungeons & Dragons Game | 1991 | TSR | United States |
| The Official Superhero Adventure Game | 1981 | — | — |
| The One Ring (2nd edition) | 2021 | — | — |
| The One Ring Roleplaying Game | 2011 | Cubicle 7 | United States |
| The Pool | 2000 | — | — |
| The Price of Freedom | 1986 | West End Games | United States |
| The Princes' Kingdom | 2006 | CRN Games | United States |
| The Quiet Year | 2013 | Buried Without Ceremony, 500 nuances de geek | United States |
| The Realm of Yolmi | 1977 | — | — |
| The Regiment | 2012 | self-published work | — |
| The Revised RECON | 1986 | Palladium Books | United States |
| The Riddle of Steel | 2002 | — | — |
| The Shadow of Yesterday | 2004 | CRN Games | United States |
| The Slayers d20 | 2003 | Guardians of Order | Canada |
| The Spawn of Fashan | 1981 | — | — |
| The Sprawl | 2016 | — | — |
| The Squared Circle | 2008 | — | — |
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| The Sundered Land | 2013 | Lumpley Games | United States |
| The Warren | 2015 | Bully Pulpit Games | United States |
| The Whispering Vault | 1993 | — | — |
| The World of Aden | — | West End Games | — |
| The World of Indiana Jones | 1994 | West End Games | United States |
| The World We Left Behind | 28 October 2024 | — | — |
| The World, the Flesh, and the Devil | 2001 | — | — |
| The Zorcerer of Zo | 2006 | Atomic Sock Monkey Press | United States |
| Theatrix | 1993 | — | — |
| Thieves' World | 1981 | Chaosium | United States |
| Thirsty Sword Lesbians | — | Evil Hat Productions | — |
| Thirty | 2005 | — | — |
| Thoan | 1995 | Jeux Descartes | France |
| Thoan : Le jeu de rôle de la saga des Hommes-Dieux | 2022 | Les XII Singes, Éditions Mnémos | France |
| Thou Art But A Warrior | 2007 | — | — |
| Tigres volants | 1990 | 2d Sans Faces | Switzerland |
| Time & Time Again | 1984 | Timeline Ltd. | United States |
| Time Lord | 1991 | Virgin Books | United Kingdom |
| Timelords | 1987 | Blacksburg Tactical Research Center | United States |
| Timemaster | 1984 | Pacesetter Ltd | United States |
| TimeWatch | 2016 | Pelgrane Press | United States |
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| Titansgrave: The Ashes of Valkana | 2015 | Green Ronin Publishing | United States |
| To Challenge Tomorrow | 1983 | — | — |
| Tomorrow Knights | 2005 | — | — |
| Toon | 1984 | Steve Jackson Games | United States |
| Top Secret | 1980 | TSR | United States |
| Torchbearer | 2013 | The Burning Wheel | United States |
| Torg | 1990 | West End Games | United States |
| Total Eclipse | 2011 | — | — |
| Trail of Cthulhu | 2008 | Pelgrane Press | United States |
| Tranchons & Traquons | 2009 | Les Livres de l'Ours | France |
| Transhuman Space | 2002 | Steve Jackson Games | United States |
| Trauma | 1986 | Chroniques d'outre-monde | France |
| Traveller | 1977 | Game Designers' Workshop, Hobby Japan | United States |
| Traveller Deluxe Edition | 1981 | Game Designers' Workshop | United States |
| Traveller Starter Edition | 1983 | Game Designers' Workshop | United States |
| Traveller: The New Era | 1993 | Game Designers' Workshop | United States |
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| Triangle Agency | 2024 | — | — |
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| Trinités | 2006 | Les XII Singes | France |
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| Trucs trop bizarres | 2017 | — | France |
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| Twilight: 2000 | 1984 | Game Designers' Workshop | United States |
| Twilight: 2013 | 2008 | — | — |
| Tähti | 2007 | — | — |
| Tékumel: Empire of the Petal Throne | 2005 | Guardians of Order | United States |