In this sci-fi fantasy, a particular arcade game is really a test, put on earth by aliens looking to find “The Last Starfighter." The only one to meet that challenge is teenager Alex. Centauri (Robert Preston) is the outer-space recruiter who takes Alex to his planet and explains that Alex is the only one left who has the skill to be the Last Starfighter. Alex refuses, and is on his way back to Earth when all of the other Starfighters are destroyed by the evil Ko-Dan. When the bad guys come after him, he agrees to stay and fight. Centauri thoughtfully leaves behind a "courtesy replacement simuloid," a robot that has Alex's looks, so his family won't worry. The simuloid, however, has no idea of how to be an Earthling, and gets into all kinds of trouble. Meanwhile, Alex is paired with Grig, a reptilian-looking alien navigator (Dan O'Herlihy). Because all of the other Starfighters have been killed, Alex must face opposition leader Zor alone.