Chow Ti is a poor construction worker. He lives in a partially demolished house with his nine-year-old son, Dicky. Chow is eager to save money so he can continue sending his son to private school. However, Dicky is often bullied by other children and his teacher at school.
Gary King (Simon Pegg), a middle-aged alcoholic, tracks down his estranged schoolfriends and persuades them to complete "the Golden Mile", a pub crawl encompassing the 12 pubs of their hometown of Newton Haven. The group attempted the crawl as teenagers, but failed to reach the final pub, The World's End.
Owen Baker (Liam Aiken) is a 12-year-old who has been working as the neighborhood dog-walker so he can earn the privilege of getting a dog of his own. Owen's hard work pays off when his parents, Mr. and Mrs. Baker (Kevin Nealon and Molly Shannon), let Owen adopt a scruffy Border Terrier that he names Hubble (voice of Matthew Broderick).
Number 5 is part of a series of prototype U.S. military S.A.I.N.T. (Strategic Artificially Intelligent Nuclear Transport) robots built for the Cold War by NOVA Laboratories. The series' inventors, Newton Graham Crosby and Ben Jabituya, are more interested in peaceful applications including music and social aid. After a demonstration of the robots' capabilities, Number 5 is hit by a lightning-induced power surge, erasing its programming and giving it a sense of free will. Several incidents allow the robot to escape the facility accidentally, barely able to communicate and uncertain of its directive. In Astoria, Oregon, Stephanie Speck (who cares for animals and mistakes Number 5 for an extraterrestrial visitor) grants Number 5 access to books, television, and other stimuli, to satisfy his hunger for 'input'; whereupon Number 5 develops a whimsical and curious childlike personality. When Stephanie realizes Number 5 is a military invention, she contacts NOVA who send out a team to recover him, bringing one of the other robots along to help. When Number 5 accidentally crushes a grasshopper and gains an understanding of mortality, he concludes that if NOVA disassembles him he too will cease to be alive. Horrified, Number 5 steals Stephanie's van and flees; but the pair are cornered by NOVA, including Newton and Ben. Although Stephanie attempts to reveal his newly discovered sentience, Number 5 is deactivated and captured. Being taken on the way to NOVA, he manages to turn himself back on and escapes despite a tracker that had been placed on him. Returning to Stephanie for protection, Number 5's unusual actions catch the attention of his creators, but NOVA's CEO Dr. Howard Marner turns a deaf ear to their wild hypothesis.
In 2688, humanity exists as a utopian society due to the inspiration of the music and wisdom of the Two Great Ones: Bill S. Preston, Esq. (Alex Winter) and Ted "Theodore" Logan (Keanu Reeves). Rufus (George Carlin) is tasked by the leaders to travel back to San Dimas, California, in 1988 using a time machine disguised as a telephone booth to ensure that Bill and Ted, who are dim-witted metalhead high school students, get a good grade in their final history oral report and allow them to pass the class. Should they fail, Ted's father, Police Captain John Logan (Hal Langdon), plans to ship Ted to a military academy in Alaska, ending Bill and Ted's fledgling band, the "Wyld Stallyns", thus altering the future.
Shermer, Illinois, is a fictitious suburb of Chicago. There, nerdy social outcasts Gary Wallace (Anthony Michael Hall) and Wyatt Donnelly (Ilan Mitchell-Smith) are publicly humiliated by Ian (Robert Downey, Jr.) and Max (Robert Rusler) after they are seen swooning over two girls who happen to be their girlfriends. Dejected and disappointed at their direction in life and wanting more, Gary convinces the uptight Wyatt that they need a boost of popularity in order to get their crushes, Hilly (Judie Aronson) and Deb (Suzanne Snyder), away from Ian and Max. Alone for the weekend with Wyatt's parents gone, Gary is inspired by the 1931 classic Frankenstein to create a virtual girl using Wyatt's computer; infusing her with everything they can conceive to make the perfect dream girl. After hooking electrodes to a doll and hacking into a government computer system for more power, a power surge creates Lisa, a beautiful and intelligent woman with seemingly endless powers. Promptly, she conjures up a Cadillac convertible to take the boys out to a bar, using her powers to manipulate people into believing Gary and Wyatt are of age. The boys come up with the name Lisa (Kelly Le Brock), based upon a failed romantic experience of Gary's that ended with Lisa kicking him in the testicles.
In September 1963, Seymour Krelborn (Rick Moranis) and his colleague, Audrey (Ellen Greene), work at Mushnik's Flower Shop, lamenting they cannot escape the slums of New York City, living in a run-down, beat up neighborhood referred to as "Skid Row." Struggling from a lack of customers, Mr. Mushnik (Vincent Gardenia) prompts to close the store, only for Audrey to suggest displaying an unusual plant Seymour owns. Immediately attracting a customer, Seymour explains he bought the plant, which he dubbed "Audrey II", from a Chinese flower shop during a solar eclipse. Attracting business to Mushnik's shop, the plant soon starts dying, worrying Seymour. Accidentally pricking his finger, he then discovers Audrey II needs human blood to thrive.
The NSA-funded QT (Quantum Tech) Corporation has slated a project to develop Hypertime, a technology which allows the user's molecules to speed up to the point where the world appears to be standing still. After realizing that such technology, contained within a wristwatch frame, could also be used against the USA, the NSA orders the project stopped. However, the research is farther along than the NSA expected and QT's leader Henry Gates plans on using the technology to usurp the leader of the NSA and dominate the world. He uses the prototype to stretch the weekend in order to give the brilliant lead scientist Earl Dopler time to fix the remaining glitch in the technology after his henchmen Richard and Jay prevent Earl's incognito departure at the airport. However, the disadvantage of Earl being in Hypertime for too long was him aging rapidly in real time, as his molecular age continued at the same rate despite time slowing down.
Planet Spaceball, led by the incompetent President Skroob, has wasted all of its air. Skroob schemes to steal air from the planet Druidia by kidnapping Princess Vespa, the daughter of King Roland on the day of her pre-arranged wedding to the narcoleptic Prince Valium. Skroob sends the villainous Dark Helmet to complete this task with Spaceball One, an impossibly huge ship helmed by Colonel Sandurz. Before they can arrive, Vespa herself abandons her marriage and flees the planet in her personal Mercedes spaceship along with her Droid of Honor, Dot Matrix.
The film opens in the utopian future that results from the music of Bill (Alex Winter) and Ted (Keanu Reeves). Chuck De Nomolos (Joss Ackland), who detests this society, steals one of the time-traveling phone booths and sends two robots modeled after Bill and Ted to the late 20th century, with the intent to prevent Bill and Ted from winning the San Dimas Battle of the Bands. Rufus (George Carlin) attempts to stop De Nomolos but becomes lost in the circuits of time.
Twenty-seven-year-old Howard the Duck (Chip Zien) lives on Duckworld, a planet similar to Earth but inhabited by anthropomorphic ducks and orbited by twin moons. As he is reading the latest issue of Playduck magazine, his armchair begins to quake violently and propels him out of his apartment building and into outer space; Howard eventually lands on Earth, in Cleveland, Ohio. Upon arriving, Howard encounters a woman being attacked by thugs. He defeats them using a unique style of martial arts. After the thugs flee, the woman introduces herself as Beverly Switzler (Lea Thompson), and decides to take Howard to her apartment and let him spend the night. The following day, Beverly takes Howard to Phil Blumbertt (Tim Robbins), a scientist who Beverly hopes can help Howard return to his world. After Phil is revealed to be only a janitor, Howard resigns himself to life on Earth and rejects Beverly's aid. He soon applies for a job as a janitor at a local romance spa. Because of unfair treatment by his boss, Howard resigns and rejoins Beverly, who plays in a band called Cherry Bomb. At the club at which Cherry Bomb is performing, Howard comes across their manager (Tommy Swerdlow), and confronts him when he insults the band. A fight breaks out, in which Howard is victorious.
The film opens on Mars, showing the last moments of a Mars rover's mission. As the rover prepares to sample a Martian rock, the rover loses power and becomes inoperable. The scene pans up from the dead rover to show a huge, undiscovered Martian city just beyond the rock the rover was about to sample. A spaceship is seen quickly rocketing from the city and accelerating into space.
Alex Rogan is a teenager living in a trailer park with his mother and little brother, Louis. Alex often plays Starfighter, an arcade game in which the player defends "the Frontier" from "Xur and the Ko-Dan Armada" in a space battle. He becomes the game's highest-scoring player, and is approached by the game's inventor, Centauri, who invites him to take a ride. Alex does so, discovering the car is a spacecraft. Centauri is an alien who takes him to the planet Rylos. An android duplicate named Beta takes Alex's place during his absence.
In the near future, the Moon has been colonized and supports a station on its surface. A lunar shuttle known as Mayflower One is being rushed to launch from Houston. The head of the ground crew, The Sarge (Chuck Connors), does not like what is occurring, but he defers to the airline's management.
Set in San Francisco, California, down-on-his-luck Naval aviator Lt. Tuck Pendleton (Quaid) resigns his commission and volunteers for a secret miniaturization experiment. He is placed in a submersible pod and both are shrunk to microscopic size. They are transferred into a syringe to be injected into a rabbit, but the lab is attacked by a rival organization, led by scientist Dr. Margaret Canker (Fiona Lewis), that plans to seize the experiment and steal the miniaturization technology.