The titular "Spaceballs" are a bunch of unscrupulous nutjobs, intent on stealing the air of the beautiful world of Druidia to save their own over used homeworld. To this end they capture a druish princess (an extremly light Jewish gag that is carried on through the film) who can only be rescued by a space bum called Lone Star and his scruffy man dog pal, Barf! But the evil Dark Helmet is not easily defeated.

Puerile and fun, this purports to be a Star Wars spoof, but pulls in many other sources along the way including Alien (complete with John Hurt) and Star Trek.