In a world populated by sentient robots, Rodney Copperbottom, son of Herb and Lydia Copperbottom from Rivet Town, is an aspiring young inventor. He idolizes Bigweld, a famous inventor, entrepreneur, and philanthropist whose company, Bigweld Industries, hires other inventors and provides robots with spare parts. Following Bigweld's example to "see a need, fill a need", Rodney develops a small, flying robot, named Wonderbot, to assist his father, Herb, who works as a dishwasher at a restaurant. When Herb's supervisor Mr. Gunk confronts them, Wonderbot malfunctions and wreaks havoc in the kitchen.
To help Herb pay for the damages, Rodney decides to move to Robot City, hoping to present Wonderbot to Bigweld Industries. Upon his arrival, Rodney is ejected from Bigweld Industries by the company's current head Phineas T. Ratchet, who, in Bigweld's absence, has stopped producing spare parts and inventions in favor of expensive "upgrades", thereby "outmoding" robots who are unable or unwilling to pay for them. Ratchet's mother, Madame Gasket, runs the Chop Shop, a facility that collects scrap and spare parts (and sometimes outmoded robots) and melts them to create ingots for Upgrades.
