| Title | Publisher | Year | Language | Documents |
|---|---|---|---|---|
| Ice Station Zero | 8th Day Software | 1985 | English | Solution, Map, Hints |
| In the Fields of Sorrow | H. W. Williams | ? | English | |
| Interpol | Antonio Cortes Gregorio | 1997 | Spanish | |
| Investigations | Graphtext 128 | 1987 | English | Solution, Map |
| Investigator, The | Lucille F. Rock | ? | English | |
| It Takes a Thief | Randy Dobkin | 1981 | English |