As ship commander navigate the galaxy destroying enemy ships, but watch your fuel and torpedo supply!
From the manual:
It is 2000 years since the unification of our planet and we "Terrans" have peacefully excelled in art, philosophy and science. Our technology has mastered all but one problem, the hyperwarp drive (which would enable us to travel to other planets). Trapped in our own solar system for lack of the hyperwarp drive, there seems to be no way out until we are discovered by extraterrestrial life. These "Aliens" are anxious to trade their hyperwarp technology for Terran art and science to revitalize their stagnant culture.
As time passes, we Terrans expand our empire through interstellar trade and the use of hyperwarp technology. Increasingly the Terrans and Aliens compete over the riches in the universe. We develop phased energy weapons (PHASORS) and force shields, while the Aliens insist on escorting their merchant envoys with warships. Tension begins to grow.
The Terran government directed by the House of Viceroys, decides to build an indestructible Starfleet and two Galactic Starbases to insure cosmic military supremacy. With the invention of a deadly photon-launcher and the virtual invisibility of the starbases (their location is a closely guarded secret), we Terrans feel that a single Super Warship can keep the scattered Alien fleet in check. You are the captain and sole commander of that warship.
While the Viceroys are relaxing and confident of our military superiority, the Alien Council of Elders rule that the Terran culture has to be destroyed. This is to be done before Alien dominance in the heavens is lost. As the Terran Starship Commander, you must throw back the Alien invasion.