| Gaean Reach: the Roleplaying Game of Interstellar Vengeance | 2014 | Pelgrane Press | United States |
| Gakuen Paradise | — | — | Japan |
| Gamma World | 1978 | TSR | United States |
| Gamma World (1st edition) | 1978 | — | — |
| Gamma World (2nd edition) | 1983 | — | — |
| Gamma World (3rd edition) | 1986 | — | — |
| Gamma World (4th edition) | 1992 | — | — |
| Gamma World (5th edition) | 2000 | — | — |
| Gamma World (6th edition) | 2003 | — | — |
| Gamma World (7th edition) | 2010 | — | — |
| Gangbusters | 1982 | TSR | United States |
| Gangster! | 1979 | — | — |
| Gatecrasher | 1996 | Grey Ghost Press | United States |
| Gear Krieg | 2001 | Dream Pod 9 | Canada |
| Geiger Counter | 2008 | self-published work | — |
| Geist: The Sin-Eaters | 2009 | White Wolf Publishing | Sweden |
| Gemini | 1998 | — | Sweden |
| Generic Universal Role Playing System | 1986 | Steve Jackson Games | United States |
| Ghost Dog: The Way of the Samurai | 2000 | Guardians of Order | Canada |
| Ghostbusters (1st edition) | 1986 | — | — |
| Ghostbusters International | 1989 | — | — |
| Ghostbusters International Rolepaying Game | 1986 | West End Games | United States |
| Ghosts of Albion Roleplaying Game | 2008 | Eden Studios, Inc. | United States |
| Ghoulash: The Last Game on Earth | 2001 | — | — |
| Godbound | 2016 | — | — |
| Godlike | 2001 | Arc Dream Publishing | United States |
| Gods, Demi-Gods & Heroes | 1976 | TSR | United States |
| Golden Heroes | 1984 | Games Workshop | United Kingdom |
| Golden Skies Stories | 2006 | — | — |
| Good Society: A Jane Austen Role-Playing Game | 2018 | — | — |
| Grey Ranks | 2007 | Bully Pulpit Games | United States |
| Grimm | 2007 | — | United States |
| Gubat Banwa | 2021 | — | Philippines |
| Guidon Dungeons & Dragons | — | — | — |
| Guilds | 1996 | Multisim | France |
| GUMSHOE System | 2007 | Pelgrane Press | United States |
| Guns!, Guns!, Guns! | 1991 | — | — |
| Gunslingers and Gamblers | 2006 | — | — |
| GURPS 4e Basic Set | 2004 | Steve Jackson Games | United States |
| GURPS 4th Edition Rulebook | 2004 | Steve Jackson Games | United States |
| GURPS Aliens | 1990 | Steve Jackson Games | United States |
| GURPS Alternate Earths II | 1999 | Steve Jackson Games | United States |
| GURPS Blood Types | 1995 | Steve Jackson Games | United States |
| GURPS Bunnies & Burrows | 1992 | Steve Jackson Games | United States |
| GURPS Conan | 1989 | Steve Jackson Games | United States |
| GURPS Cyberpunk | 1990 | Steve Jackson Games | United States |
| GURPS Discworld | 1998 | Steve Jackson Games | United States |
| GURPS Espionage | 1992 | Steve Jackson Games | United States |
| GURPS Fantasy | 1986 | Steve Jackson Games | United States |
| GURPS Fantasy Bestiary | 1990 | Steve Jackson Games | United States |
| GURPS Gulliver | 1997 | Steve Jackson Games | United States |
| GURPS Horseclans | 1987 | Steve Jackson Games | United States |
| GURPS Humanx | 1987 | Steve Jackson Games | United States |
| GURPS Ice Age | 1989 | Steve Jackson Games | United States |
| GURPS Infinite Worlds | 2005 | Steve Jackson Games | United States |
| GURPS Middle Ages I | 2002 | Steve Jackson Games | United States |
| GURPS Reign of Steel | 1997 | Steve Jackson Games | United States |
| GURPS Robin Hood | 1992 | Steve Jackson Games | United States |
| GURPS Runal | 1992 | Steve Jackson Games | United States |
| GURPS Shapeshifters | 2003 | Steve Jackson Games | United States |
| GURPS Space | 1988 | Steve Jackson Games | United States |
| GURPS Super Scum | 1989 | Steve Jackson Games | United States |
| GURPS Supers | 1989 | Steve Jackson Games | United States |
| GURPS Swashbucklers | 1988 | Steve Jackson Games | United States |
| GURPS Timeline | 1992 | Steve Jackson Games | United States |
| GURPS Traveller | 1998 | Steve Jackson Games | United States |
| GURPS Traveller: Interstellar Wars | 2006 | Steve Jackson Games | United States |
| GURPS Witch World | 1989 | Steve Jackson Games | United States |