| M.I.S.S.I.O.N. | 1982 | — | — |
| Macchiato Monsters | 2017 | — | France |
| Mach: The First Colony | 1983 | — | — |
| Macho Women with Guns | 1988 | Blacksburg Tactical Research Center | United States |
| Macross II: The Role-Playing Game | 1993 | Palladium Books | United States |
| Maelstrom | 1984 | Chaosium | United States |
| Mage: The Ascension | 1993 | White Wolf Publishing | United States |
| Mage: The Ascension (1st edition) | 1993 | White Wolf Publishing | — |
| Mage: The Ascension (20th anniversary edition) | 2015 | — | — |
| Mage: The Ascension (2nd edition) | 1995 | White Wolf Publishing | — |
| Mage: The Ascension (revised edition) | 2000 | — | — |
| Mage: The Awakening | 2005 | White Wolf Publishing | United States |
| Mage: The Sorcerers Crusade | 1998 | White Wolf Publishing | United States |
| Magical Kitties Save the Day! | — | Atlas Games | — |
| Magician's Academy RPG | December 2008 | — | Japan |
| Maid: The Role-Playing Game | 2004 | — | Japan |
| Malefices | 1984 | Jeux Descartes | France |
| Man, Myth & Magic | 1982 | — | — |
| Manga BoyZ | 2008 | — | — |
| Marc Miller's Traveller | 1996 | Imperium Games | United States |
| Marvel Heroic Roleplaying | 2012 | Margaret Weis Productions | United States |
| Marvel Multiverse Role-Playing Game | 2022 | Marvel Comics | — |
| Marvel Super Heroes | 1984 | TSR | United States |
| Marvel Super Heroes Advanced Set | 1986 | TSR | United States |
| Marvel Super Heroes Adventure Game | 1998 | TSR | United States |
| Marvel Super Heroes: The Heroic Role-Playing Game | 1984 | TSR | United States |
| Marvel Universe Roleplaying Game | 2003 | — | United States |
| Masks: a New Generation | 2016 | Magpie Games | United States |
| Masterbook | 1994 | West End Games | United States |
| Mayfair Exponential Game System | — | — | — |
| Mazes & Minotaurs | 2006 | — | — |
| Mazes & Perils | 2011 | — | — |
| Mechamorphosis | 2004 | — | — |
| Mechanical Dream | 2002 | — | Canada |
| MechWarrior | 1986 | FASA Corporation | United States |
| Mega | 1984 | Jeux et Stratégie | France |
| MEGA Role-Playing System | 1987 | — | — |
| MegaTraveller | 1987 | Game Designers' Workshop | United States |
| Megaversal system | 1981 | Palladium Books | United States |
| Mekton | 1985 | R. Talsorian Games | United States |
| Melanda: Land of Mystery | 1980 | R. Talsorian Games | United States |
| Men In Black: The Roleplaying Game | 1997 | West End Games | United States |
| Merc | 1981 | — | — |
| Mercenaires | 1991 | — | — |
| Mercenaries, Spies and Private Eyes | 1983 | Flying Buffalo | United States |
| Metal Adventures | 2009 | — | — |
| Metamorphosis Alpha | 1976 | TSR | United States |
| Michtim: Fluffy Adventures | 2012 | — | — |
| Middle-Earth Role Playing | 1984 | Iron Crown Enterprises | United States |
| Midgard | 1981 | — | Germany |
| Midnight at the Well of Souls Role-Playing System | 1985 | — | — |
| Miekkamies | — | — | Finland |
| Miles Christi | 1995 | Sans peur et sans reproche | France |
| Millenia | — | — | Brazil |
| Millennium's End | 1991 | — | — |
| Mindjammer | 2014 | Modiphius Entertainment | United Kingdom |
| MIR | 2024 | — | — |
| Mist-Robed Gate | 2007 | — | United States |
| Mistborn Adventure Game | 2011 | — | — |
| Mobsters | 1998 | — | Finland |
| Monastyr | 1999 | Portal | Poland |
| Mongoose Runequest | 2006 | Mongoose Publishing | United States |
| Monkey, Ninja, Pirate, Robot: the Roleplaying Game | 2004 | Atomic Sock Monkey Press | United States |
| Monostatos | 2012 | self-published work | France |
| Monster of the Week | 2012 | Evil Hat Productions | United States |
| Monsterhearts | 2012 | Buried Without Ceremony | United States |
| Monsterhearts (1st edition) | 2012 | Buried Without Ceremony | United States |
| Monsterhearts 2 (2nd edition) | 2017 | — | United States |
| Monsters and Other Childish Things | 2007 | — | — |
| Montsegur 1244 | 2009 | — | — |
| Monty Python’s Cocurricular Mediaeval Reenactment Programme | 2025 | — | — |
| Morpheus | 1990 | — | — |
| Morton's List | 2012 | — | — |
| Mothership | 2018 | Tuesday Knight Games | — |
| Multimondes | 1988 | Oriflam | France |
| Multiverser | 1997 | — | — |
| Mummy: The Curse | 2013 | Onyx Path Publishing | United States |
| Mummy: The Resurrection | 2001 | White Wolf Publishing | United States |
| Murderous Ghosts | 2012 | Night Sky Games | United States |
| Murphy's World | 1995 | — | — |
| Mutant | 1984 | Target Games | Sweden |
| Mutant Chronicles | 1993 | Target Games | Sweden |
| Mutant City Blues | 2009 | Pelgrane Press | United States |
| Mutant Crawl Classics | 2017 | Goodman Games | United States |
| Mutant Future | 2008 | — | — |
| Mutant: Undergångens arvtagare | 2001 | Järnringen | Sweden |
| Mutantes en la sombra | April 1991 | Ludotecnia | Spain |
| Mutants & Masterminds | 2002 | Green Ronin Publishing | United States |
| Mutazoids | 1989 | — | — |
| My Life with Master | 2003 | Half Meme Press | United States |
| My Little Pony: Tails of Equestria | 2016 | — | — |
| Myrskyn aika | 2003 | — | Finland |
| Mythic Bastionland | 2025 | Bastionland Press | — |
| Mythos | 2008 | — | Italy |
| Mythworld | 1986 | — | — |
| Mörk Borg | 2019 | Free League Publishing | Sweden |