1–4 Players | 1992 | Board Games | Board Games that Start with T | Deduction | Electronic | Exploration | Family | Long Games (Over 2 hours) | Older Teen (14+) | Science Fiction | Thematic The Omega Virus (1992)
1987 | 2 Players | Board Games | Board Games that Start with O | Quick Games (Under 30 minutes) | Teen (12+) | Wargame | World War II Onslaught (1987)
1 Players | 1988 | Adventure | Board Games | Board Games that Start with O | Short Games (30 minutes to 1 hour) | Teen (12+) | Wargame | World War II Open Fire: Solitaire Tank Combat in WWII (1988)
1–6 Players | 1965 | Action / Dexterity | Board Games | Board Games that Start with O | Children's Game | Medical | Primary Schooler (6+) | Short Games (30 minutes to 1 hour) Operation (1965)
1970 | 2 Players | Board Games | Board Games that Start with O | Expansion for Base-game | Quick Games (Under 30 minutes) | Teen (12+) | Wargame | World War II Operation ‘GREIF’ (1970)
1981 | 2 Players | Abstract Strategy | Board Games | Board Games that Start with O | Quick Games (Under 30 minutes) Order and Chaos (1981)
1974 | 2–4 Players | Board Games | Board Games that Start with O | Economic | Mafia | Negotiation | Older Teen (14+) | Political | Short Games (30 minutes to 1 hour) | Strategy Organized Crime (1974)
1967 | 2 Players | Action / Dexterity | Board Games | Board Games that Start with O | Mature / Adult | Party Game | Short Games (30 minutes to 1 hour) Orgy (1967)
1–6 Players | 1985 | Board Games | Board Games that Start with O | Deduction | Medium-Length Games (1 to 2 hours) | Murder/Mystery | Teen (12+) | Thematic | Trains Orient Express (1985)
1971 | 2–5 Players | Board Games | Board Games that Start with O | Medium-Length Games (1 to 2 hours) | Negotiation | Political | Strategy | Teen (12+) | Wargame | World War II Origins of World War II (1971)
2 Players | 2006 | Abstract Strategy | Board Games | Board Games that Start with O | Junior (8+) | Long Games (Over 2 hours) | Mythology Oshi (2006)
