Dark Helmet gets knocked out by a robot stripper in Skroobs new casino and recalls his origin story as in a dream. Once a young slave named Pannakin Crybaby, he won his freedom in a NasPodrace, was trained in the Schwartz by Yogurt and fell in love with Princess Harley Van Patten.
Lone Starr and Princess Vespa are sucked into a game of 'Grand Theft Starship', leaving the Spaceballs to conquer the known universe. But, missing Lone Starr's opposition, President Skroob and Dark Helmet follow them into the game world.
Years ago Lonestarr's father stole the One Onion ring from Scroob's father. When Barf finds the Onion Ring stuck in an old couch inside the Eagle 5, Yogurt sends him on a quest to throw the Onion Ring into the deep fryer of Lardor. Meanwhile Skroob orders Dark Helmet to build him a dark army. Unfortunately they end up with a dork army instead.
Lone Starr and Barf are named fans of the day at a Spankees ball game and win a trip to Watch your Assic Park to see the Spankees train. After they arrive at Isla Nueblo (180 star miles from Planet Costa Rica) they learn how Skroob, the owner of the Spankees, uses a combination of steroids and dinosaur DNA to create Dino-athletes and rule the sports universe. Despite being quite disgusted, Lone Starr, Barf, Vespa and Dot take the park tour anyway, accompanied by Skroob's precocious 9 year old niece Jasmine and two anonymous lawyers.
Lone Starr and Barf are invited back to the annual golf tournament at Mawgwarts academy of golf and magic. During the tournament the face the Dragonian gopher of fire and stiff competition from Darko and Prof. Snapple.
Princess Vespa boards a giant cruise ship on her maiden voyage around the tip of Areola. Little does she suspect Scroob and Helmet are out to kidnap her again. Luckily Lone Starr and Barf win some tickets in a strip poker game as well.
Lone Starr needs a million Starbucks to pay Vinnie protection money. Vespa wants a million Starbucks to buy matching his and hers space-jets. So Vespa enters the Druidian Idol singing competition as 'Vespacia' and Barf as 'Kelly Barfson'. But President Scroob, anticipating their presence, uses a brain-zapper to turn the entire audience into mindless killers.
Barf is bitten by a chest-bursting alien spider and becomes Spidermawg, just in time to save his home planet from the nasty no good Spaceballs. But President Scroob uses a new weapon to become the super powered Mothball as well.