| I Cavalieri del Tempio | 1990 | — | Italy |
| Ikuisuuden laakso | 2009 | — | Finland |
| Immortal: The Invisible War | 1993 | — | — |
| Imperium5 | 2022 | — | France |
| In a Wicked Age | 2007 | Lumpley Games | United States |
| In Nomine | 1997 | Steve Jackson Games | United States |
| In Nomine Satanis - Magna Veritas (1st edition) | 1990 | — | — |
| In Nomine Satanis - Magna Veritas (2nd edition) | 1993 | — | — |
| In Nomine Satanis / Magna Veritas | 1989 | — | France |
| In Nomine Satanis / Magna Veritas (3rd edition) | 1997 | — | — |
| In Nomine Satanis / Magna Veritas (4th edition) | 2003 | — | — |
| In Nomine Satanis / Magna Veritas - Génération perdue | 2015 | — | — |
| Incursion | 1992 | — | — |
| Index Card RPG | 2017 | — | — |
| Infernum | 2005 | — | — |
| Infinite Armies | 2005 | Blacksburg Tactical Research Center | United States |
| Infinity | 1979 | — | — |
| Infinity the Roleplaying Game | 2018 | Modiphius Entertainment | United Kingdom |
| Inflorenza | 2014 | self-published work | France |
| Inner City | 1982 | — | — |
| Innommable | 2009 | self-published work | France |
| INS/MV Apéro | 2006 | — | — |
| InSpectres | 2002 | Memento Mori Theatricks | United States |
| Interlock System | 1987 | R. Talsorian Games | United States |
| Into the Odd | 2014 | — | — |
| Iron Heroes | 2005 | — | — |
| Iron Kingdoms | 2004 | Privateer Press | United States |
| Ironclaw | 1999 | Sanguine Productions | United States |
| Ironhedge | 1979 | — | — |
| Ironsworn | 2018 | — | — |
| It Came From the Late, Late, Late Show | 1989 | — | — |
| It Was a Mutual Decision | 2006 | Adept Press | United States |
| Itras By | 2008 | — | — |