Obduction by Graham

Obsidian

- Walkthrough by Mike Marcelais

- Walkthrough By Soren Andersen

Oddworld: Abe's Oddysee - Strategy Guide by Sinjin

Oddworld: Abe's Exoddus

- Walkthrough by George K. Ison

- Strategy Guide by Sinjin

Oddworld: Munch's Oddysee - Strategy Guide by Sinjin

Odyssey: The Search for Ulysses

- Walkthrough by Crash

- Walkthrough by Tally Ho

- Walkthrough by Phoubeecya

Of Light and Darkness

- Walkthrough by P. Hart

- Guide by the Questers

Okyntt (official walkthrough)

Omega Stone (The)

- Walkthrough by MaGtRo and NKuderna

- Walkthrough by Graham

Opera Fatal - Walkthrough by MaGtRo

(Undercover:) Operation Wintersun by MaGtRo

Opsys-The Game - Walkthrough by MaGtRo and Norma Kuderna

(The) Oracle - Walkthrough by Chief

Order of the Thorn: King's Challenge by MaGtRo

Orion Burger - Solution by Arthur Soedjadi

Out of Order - Walkthrough by MaGtRo

Outcry (Sublustrum) by MaGtRo

(Tex Murphy) Overseer

- Walkthrough by Crash

- Walkthrough by Dan Kennedy

- Walkthrough by Tyler Russell

Overclocked - Walkthrough by Nickie

Oz Orwell and the Crawling Chaos by Bert Jamin

Oz Orwell and the Exorcist by Judy Adams