| Title |
Publisher |
Year |
Language |
Documents |
| Obituario |
Santiago Eximeno |
2002 |
Spanish |
|
| Ocaso Mortal |
Dhan |
2001 |
Spanish |
|
| Occult Connection, The |
David Munden |
1993 |
English |
|
| October 31st |
Finn Rosenløv |
2022 |
English |
Solution |
| Old Fogey |
Simon Deimel |
2015 |
English |
|
| Old Sherwood Cemetary, The |
Duchess |
2002 |
English |
Solution, Map |
| One Dark Night |
Paul Brunyee |
1988 |
English |
Solution, Map |
| One Eye Open |
Carolyn VanEseltine, Colin Sandel |
2010 |
English |
|
| Only After Dark |
Gunther Schmidl |
1999 |
English |
Solution, Map |
| Ooze - Als die Geister Murbe Wurden |
Ariolasoft, Dragonware |
1988 |
German |
Solution |
| Ooze: Creepy Nites |
Dragonware |
1989 |
English |
Solution |
| Oriental |
Arcadia S.r.l., Load 'n' Run  |
1986 |
Italian |
Solution, Map |
| Ork! House of Fortune |
Brett Walker |
1989 |
English |
Map, Hints |
| Orson Powell: Lycanthropus |
Viking  |
1987 |
Italian |
Solution |