In UFO one player, representing Earth, deploys satellites, interceptors, and space stations to prevent the other player, representing the UFOs, from reaching the planet. The map is approximately 11"x14" and depicts an area of space somewhat larger than the orbit of the Moon, which is depicted. A counter is provided for the Moon which moves along the orbit during the game, although presumably not very much since each game turn represents three hours. A pad of sheets is provided for the players to plot movement simultaneously. Movement is three-dimensional. Damage is incremental and after combat players may attempt to repair damaged units. There are six scenarios and a 25-turn campaign game which has production rules allowing players to purchase additional or replacement units.