| System (Setting) | Publications | Articles |
|---|---|---|
 I Am Providence | 1 | 1 |
| I Am the Fourth Wall | 1 | 1 |
 I Pray God Will Curse the Writer | 1 | 1 |
| Iaa! Cthulhu! Fhtagn! | 1 | 1 |
| ICONS | 5 | 5 |
| Immortal: The Invisible War | 1 | 1 |
| In the Depths of Silverstring | 1 | 1 |
| Incredible Expeditions | 2 | 2 |
| Index Card RPG | 1 | 1 |
| Infaernum | 1 | 1 |
| Innsmouth 32 | 1 | 1 |
| The Innsmouth Curse | 1 | 1 |
| Innsmouth Escape | 1 | 1 |
| Innsmouth Mystery | 1 | 1 |
| The Innsmouth Papers | 1 | 1 |
| Innsmouth: The Stolen Child | 1 | 1 |
| Interface Zero | 1 | 13 |
| Into the Shadows | 1 | 1 |
| It Came from the Wild Blue Yonder | 1 | 1 |