Professor Philip Brainard (Robin Williams) of Medfield College is developing a new energy source, in an attempt to raise enough money to save the college from closure. His preoccupancy with his research distracts him from his fiancée and the college president Sara Jean Reynolds (Marcia Gay Harden); he has missed two weddings in the past as a result of this, much to the anger of Sara. On the day of the third attempted wedding, Philip is approached by his former partner Wilson Croft (Christopher McDonald), who has profited from ideas he has stolen from the chemist and now desires to steal Sara from Philip and make her his wife, which he declares directly to Philip. Before he can make it to the wedding, his latest experiment shows fast development, forcing him to miss another wedding. The resulting substance created from the experiment is a living green goo that increases in speed as it bounces and proves to be difficult to control, wreaking havoc on the neighborhood before the professor finally manages to capture it. Weebo (voiced by Jodi Benson), Philip's hovering robot assistant, classifies the substance as "flying rubber", leading Philip to christen it as "Flubber".
Philip continues to work on Flubber into the early morning, looking to stabilize the Flubber's movement as opposed to stimulation. Philip's watch alarm goes off at 6 a.m. (set wrong) and Weebo informs him that he has missed the third wedding. Philip goes to Sara's office and unsuccessfully attempts to explain the situation to her. Meanwhile, Medfield College sponsor Chester Hoenicker (Raymond J. Barry) is unhappy that Philip failed his son Bennett (Wil Wheaton) in chemistry class. That night, Hoenicker sends his two security guards Smith (Clancy Brown) and Wesson (Ted Levine) to Philip's house in an attempt to persuade Philip into giving Bennett a better grade. However, Philip is too busy testing the Flubber to even notice them and suddenly knocks them out unconscious with a Flubber-coated golf ball and bowling ball. He uses Flubber to give his vintage Ford Thunderbird flight. During a test run, he discovers Wilson making the moves on Sara (making a bet that she'll buy him dinner if Medfield wins, or join him for a weekend in the mountains if they lose). Afterward, Weebo attempts to confess her love of Philip, only to be shrugged off as a computer. In response, she secretly creates a holographic human version of herself named Sylvia (Leslie Stefanson) in hopes of winning him over. Before Weebo can make out with Philip in this form as he sleeps, Philip awakens with another idea for Flubber. He enters an empty basketball arena and tests the effects of Flubber on a basketball. Later, he gives Flubber-padded shoes to the unskilled Medfield basketball team to increase their abilities.
Back in Philip's home, a spiteful Weebo unleashes Flubber from his case, allowing him to dance around the house and cause general mayhem. After the close but successful basketball game, Philip's attempt to win Sara back into his favor fails. Philip dumps all of his emotional baggage onto Weebo, saying his absent-mindedness is due to his love of Sara. Weebo records Philip's ramblings and shows the footage to Sara, who then reconciles with Philip. Philip demonstrates Flubber's abilities to Sara and they discuss how it can be used for profit. However, Hoenicker discovers Flubber's existence and sends Smith and Wesson to infiltrate Philip's house and steal Flubber. Weebo attempts to fend off the henchmen, only to be struck down by Wesson with a baseball bat. Philip and Sara return home and find Weber (Philip's house-robot) cleaning up, Flubber gone, and Weebo destroyed. Later, Philip discovers that Weebo had downloaded backup data of herself onto his computer in the event of her destruction, as well as a video recording of Weebo's hologram professing her love for him.
Philip and Sara confront Hoenicker and try to retrieve Flubber, only to discover that Wilson is allied with the millionaire. After a battle, Philip and Sara defeat Wilson, Bennett, Hoenicker and his henchmen, get Flubber back, raise enough money to save the college and finally have a successful marriage, along with Flubber and the "daughter" of Weebo, called Weebette. The film ends with the family heading to Hawaii in the Thunderbird.Robin Williams as Professor Philip Brainard
Marcia Gay Harden as Sara Jean Reynolds
Jodi Benson as the voice of Weebo
Edie McClurg as Martha Croft
Clancy Brown as Smith
Christopher McDonald as Wilson Croft
Wil Wheaton as Bennett Hoenicker
Ted Levine as Wesson
Raymond J. Barry as Chester Hoenicker
Scott Martin Gershin provided the voices of the Flubber
Filming began in San Francisco on Treasure Island in Hangers 1 and 3. Sets constructed there included the basketball court, a duplicate of the Professor's house where some exterior and all interior shots were produced, a separate set portraying the basement of the house, and Hoenicker's library. Many exterior shots of Brainard's house were shot in San Jose at a home that was temporarily modified, including the addition of an Observatory on the roof. Sara Jeans office, Hoenicker's living room, and most exterior campus shots were produced at a private girls High School on the San Francisco peninsula. The exterior shot of the Rutland gym was shot at Stanford. Some scenes were filmed on campus at San Jose State University in Washington Square Hall during production in 1997. The shot of the Professor and Sara Jean floating through the clouds in the Thunderbird was filmed at the former Mare Island Naval facility in Vallejo, California. Other scenes were filmed at the University of the Pacific, Stockton.
Many gags are embellishments from the 1961 film; John Hughes rewrote the original Bill Walsh screenplay (based on Samuel W. Taylor's short story, A Situation of Gravity). Though Walsh died in 1975, he received posthumous credit for this script.
Flubber made $93 million in the United States and a total of $85 million in other countries for a total of $178 million internationally.
Flubber was first released on VHS and Laserdisc on April 21, 1998,. The DVD was released in 2003.
The film holds a 23% approval rating at Rotten Tomatoes based on 31 reviews; the average rating is 3.8/10. Metacritic gives the film a score of 37/100 based on 19 reviews.