The battle for supremacy amongst the splinters of the great Terran Commonwealth has led to an arms race. The remnants of the Old Commonwealth have just unleashed the colossal Leviathan-class battleship against their enemies. With the ability to carry itself and four attached warships through a jump, an arsenal capable of leveling cities, and two fighter wings of 48 fighter craft each, the arrival of a Leviathan-class in any system spells trouble for any of the Commonwealth's enemies.

In response, the Commonwealth's primary opponent, the Callistonian Empire hastily responded with the Hydra-class supercarrier loaded with three fighter wings and equipped with devastating missile barrages powerful enough to keep any would-be attackers at bay.

In Leviathan, captains must learn to carefully manage power, as warships never seem to have enough. Power is allocated over the course of gameplay and used to maneuver the ship, power weapons, and activate defenses. As ships are damaged their systems lose effectiveness, and structural integrity degrades. Once the integrity is gone, so is the ship.
Captains are the ultimate authority on a ship but bear the weight of responsibility upon their shoulders. Not only must they maintain situational awareness, but position wisely, direct attack and defense, adjust power, prioritize repairs, and manage the crew's morals.
Ships range in size from the nimble cutters and scouts to the massive Leviathan-class battleship and Hydra-class supercarrier. Fighter groups represent the position of squadrons and flights that are flying on bombing-runs and interceptors attempting to stop them.

Ship models range in size from the smaller Javelin-class scout at three inches long up to the Leviathan-class at thirteen inches long.

The Leviathan Core Rulebook is 236 full color pages of the rules needed to play Leviathan. Basic rules cover movement, attack and defense as well as power allocation. Separate chapters cover a full turn game play example, Fighters and Advanced optional rules.