Combat Moonbase is a set of rules for tactical spaceship combat using miniatures (1/400 scale, according to the rules). Rules are provided (in Attack Wargaming's inimitable style) for lasers, missiles, plasma torpedoes, ECM, chaff, and landing and taking off from planets.

Information is provided for three types of ships, two from the Eastern Coalition and Western Alliance (who are fighting over the titular moonbase) and one from the alien Thook. It is not clear if this background is shared with any other Attack Wargaming games.