The Organian Peace Treaty has collapsed, and the Federation is at war with the Klingon Empire. Joining the Klingons against the Federation are the members of the "Romulan Star Empire." As commander of the Starship U.S.S. Enterprise, your job is to wipe out the Klingon invasion fleet and make the galaxy safe for democracy.
Your battleground is the entire galaxy, which for convenience is divided up into eight rows of eight quadrants each, like a checkerboard. Rows are numbered from top to bottom, and columns are numbered left to right, so quadrant 1 - 8 would be in the upper right hand corner of the galaxy.
You have weapons: phasers and photon torpedoes. You have a defense: deflector shields. You can look at things: long-range scaners, short-range scanners, and a star chart. You can move about, under warp drive or impulse power. You can also dock at a starbase, rest while repairs are being made, abandon ship, self destruct, or give up and start a new game.
The Klingons are waiting.
source: game manual