In Philadelphia in 1961, Elijah Price is born with Type I osteogenesis imperfecta, a rare disease that renders sufferers' bones extremely fragile and prone to fracture. As revealed later in flashbacks, Elijah—who grows up to become a comic-book art dealer—develops a theory, based on the comics he has read during his many hospital stays, that if he represents extreme human frailty, there must be someone "unbreakable" at the opposite extreme.
Years later, another Philadelphia man, security guard David Dunn, is also searching for meaning in his life. He had given up a promising football career during his collegiate days to marry Audrey after they were involved in an auto accident. Now, however, their marriage is dissolving, to the distress of their young son Joseph.
As he returns home from a job interview in New York City, David's train crashes, killing the other 131 passengers, while he is the only survivor, sustaining no injuries. At the memorial for the crash's victims, he finds a card on his car's windshield, inviting him to Elijah's store. Elijah proposes to David that he is the kind of person after whom comic-book superheroes are modeled, and repeatedly pursues the issue with David and Audrey, trying to learn if David had ever been ill or injured during childhood. Although Elijah unsettles him, David begins to test himself. While lifting weights with Joseph, he bench presses about 350 pounds (160 kg), well above what he had thought he could do. Joseph begins to idolize his father and believes he is a superhero, although David still maintains he is "an ordinary man."
David challenges Elijah with an incident from his childhood when he almost drowned. Elijah suggests that the incident highlights the common comic trope whereby superheroes often have one weakness; he contends David's might be water. While surveying the stored wreckage of the train crash that he survived, David recalls the car accident that ended his athletics career, remembering that he was unharmed and ripped a door off the car in order to save Audrey. David used the accident as an excuse to quit football because Audrey did not like the violence of the sport.
Under Elijah's influence, David develops what he thought was an unusual insight into human behavior into an extrasensory perception that enables him to glimpse criminal acts committed by the people who make contact with him. At Elijah's suggestion, David stands in the middle of a crowd in Philadelphia's 30th Street Station. As various people bump into him, he senses the crimes they perpetrated, such as theft and rape, and finds one he can act on: a sadistic janitor who invades a family home, kills the father, and holds the wife and their two children captive.
David follows the janitor to the victims' house, frees the children and finds their mother raped and killed, but the janitor ambushes him and pushes him off a balcony into a swimming pool. David nearly drowns (since he cannot swim), but the children rescue him. He then attacks the janitor from behind and strangles him to death while once more remaining uninjured. That night, he and Audrey reconcile. The following morning, he secretly shows a newspaper article on the anonymous heroic act, featuring a sketch of David in his hooded rain poncho, to his son, who recognizes the hero as his father.
David attends an exhibition at Elijah's comic book art gallery and meets Elijah's mother, who explains the difference between villains who fight heroes with physical strength versus those who use their intelligence. Elijah brings David to the back room of his studio, extends his hand, and asks David to shake it. Upon doing so, David sees visions of Elijah orchestrating several terrorist disasters, including David's recent train accident, causing hundreds of deaths. David is horrified, but Elijah insists the deaths were justified as a means to find him. Calling himself "Mr. Glass", a nickname his peers had used to taunt him with when he was growing up, he explains that his own purpose in life is to be the villain to David's hero.
Screen captions reveal that David reported Elijah's actions to the police, and that Elijah was convicted of murder and terrorism and committed to an institution for the criminally insane.
When M. Night Shyamalan conceived the idea for Unbreakable, the outline had a comic book's traditional three-part structure (the superhero's "birth", his struggles against general evil-doers, and the hero's ultimate battle against the "archenemy"). Finding the birth section most interesting, he decided to write Unbreakable as an origin story. During the filming of The Sixth Sense, Shyamalan had already approached Bruce Willis for the lead role of David Dunn. With Willis and Samuel L. Jackson specifically in mind for the two leading characters, Shyamalan began to write Unbreakable as a spec script during post-production on The Sixth Sense.
With the financial and critical success of The Sixth Sense in August 1999, Shyamalan gave Walt Disney Studios a first look deal for Unbreakable. In return, Disney purchased Shyamalan's screenplay at a "spec script record" for $5 million. He was also given another $5 million to direct. Disney decided to release Unbreakable under their Touchstone Pictures banner. It also helped Shyamalan establish his own production company, Blinding Edge Pictures. Julianne Moore dropped out of portraying Audrey, David's wife, in favor of her role as Clarice Starling in Hannibal. Robin Wright Penn was cast in her place. Principal photography began on April 25, 2000 and ended that July. The majority of filming took place in Philadelphia, Pennsylvania, the film's setting.
Shyamalan and cinematographer Eduardo Serra chose several camera angles to simulate the look of a comic book panel. Various visual narrative motifs were also applied. Several scenes relating to the Mr. Glass character involve glass. As a newborn, he is primarily seen reflected in mirrors, and as a young child, he is seen reflected in a blank TV screen. When he leaves his calling card on the windshield of David Dunn's car, he is reflected in a glass frame in his art gallery. Jackson requested his walking stick be made of glass to make his character more menacing. Using purple as Mr. Glass' color to David Dunn's green was also Jackson's idea. Mr. Glass' wig was modeled after Afro-American statesman Frederick Douglass. As he does in his other films, Shyamalan makes a cameo appearance. He plays a man David suspects of dealing drugs inside the stadium.
More than 15 minutes of footage was deleted during post-production of Unbreakable. These scenes are available on the DVD release.
Willis and Jackson had previously worked together on Die Hard with a Vengeance, Pulp Fiction and Loaded Weapon 1.
Film score composer James Newton Howard was approached by Shyamalan to work on Unbreakable immediately after scoring The Sixth Sense. "He sat there and storyboarded the whole movie for me", Howard said. "I've never had a director do that for me." Shyamalan wanted a "singularity" tone for the music. "He wanted something that was very different, very distinctive, that immediately evoked the movie when people heard it," Howard explained. Howard and Shyamalan chose to simplify the score, and minimized the number of instruments (strings, trumpets and piano), with limited orchestrations. Some compositions were recorded in a converted church in London. "You could have recorded the same music in a studio in Los Angeles, and it would have been great, but there is something about the sound of that church studio," Howard remarked. "It's definitely more misterioso."
Unbreakable was released in the United States on November 22, 2000, in 2,708 theaters and grossed $30.3 million in its opening weekend, finishing second at the box office. The film ended up earning $95 million domestically and $153.1 million internationally for a total of $248.1 million, against its $75 million production budget.
Unbreakable received generally positive reviews from critics. On Rotten Tomatoes the film has an approval rating of 68% based on 161 reviews, with an average rating of 6.2/10. The site's critical consensus states, "With a weaker ending, Unbreakable is not as a good as The Sixth Sense. However, it is a quietly suspenseful film that intrigues and engages, taking the audience through unpredictable twists and turns along the way." On Metacritic the film has a score of 62 out of 100, based on 31 critics, indicating "generally favorable reviews".
Roger Ebert largely enjoyed the film, but was disappointed with the ending. Ebert believed that Willis' "subtle acting" was positively different from the actor's usual work in "brainless action movies". Richard Corliss of Time magazine reviewed that Unbreakable continued Shyamalan's writing/direction of "balancing sophistication and horror in all of his movies". Desson Thomson from The Washington Post wrote that "just as he did in The Sixth Sense, writer-director M. Night Shyamalan leads you into a fascinating labyrinth, an alternative universe that lurks right under our noses. In this case, it's the mythological world and, in these modern times, the secret design to that labyrinth, the key to the path, is contained in comic books."
Kenneth Turan, writing in Los Angeles Times, gave a negative review, arguing that Unbreakable had no originality. "Whether it means to or not, the shadow of The Sixth Sense hangs over Unbreakable," Turan reasoned. "If The Sixth Sense hadn't been as big a success as it was, this story might have been assigned to oblivion, or at least to rewrite." Todd McCarthy of Variety mostly criticized Shyamalan's writing and the performances given by the actors. He did praise Dylan Tichenor's editing and James Newton Howard's music composition.
Shyamalan admitted he was disappointed by the reaction Unbreakable received from the public and critics. Shyamalan also disliked Touchstone Pictures' marketing campaign. He wanted to promote Unbreakable as a comic book movie, but Touchstone insisted on portraying it as a psychological thriller, similar to The Sixth Sense.
In 2009, filmmaker Quentin Tarantino praised Unbreakable, and included it on his list of the top 20 films released since 1992, the year he became a director. Tarantino praised the film as a "brilliant retelling of the Superman mythology", and said it contains what he considers to be Bruce Willis' best performance. He also criticized the way the film was marketed upon release, stating he felt that it would have been far more effective if the film's advertising simply posed the question of "what if Superman was here on earth, and didn't know he was Superman?" In 2011, Time ranked the film at #4 in its list of top ten superhero movies of all time, describing it as one of the best superhero origin stories and as a "relatively quiet, subtle and realistic look at the pressures that come with being a superhero."
After the film's release, rumors of possible sequels began circulating in different interviews and in film fansites. In 2000, Bruce Willis was quoted as hoping for an Unbreakable trilogy. In December 2000, Shyamalan denied rumors he wrote Unbreakable as the first installment of a trilogy, saying he was not even thinking about it. In August 2001, Shyamalan stated that, because of successful DVD sales, he had approached Touchstone Pictures about an Unbreakable sequel, an idea Shyamalan said the studio originally turned down because of the film's poor box office performance. In a September 2008 article, Shyamalan and Samuel L. Jackson said there was some discussion of a sequel when the film was being made, but that it mostly died with the poor box office. Jackson said he was still interested in a sequel but Shyamalan was non-committal. In February 2010, Willis said that Shyamalan was "still thinking about doing the fight movie between me and Sam that we were going to do", and stated that as long as Jackson was able to participate he would be "up for it".
In September 2010, Shyamalan revealed that the second planned villain from the first film was moved to the planned sequel, but that character has now been used for an upcoming film that he will write and produce.
Shyamalan's horror thriller film Split has been described as a thematic sequel to Unbreakable, and was released on January 20, 2017. It is revealed that Split actually takes place in the same fictional storyline, with Bruce Willis's character appearing in a final reveal, directly referencing Mr. Glass when discussing the film's villain, "The Horde".
Shyamalan expressed hope for a third installment following Split, saying, "I hope [a third Unbreakable film happens]. The answer is yes. I'm just such a wimp sometimes. I don't know what's going to happen when I go off in my room, a week after this film opens, to write the script. But I'm going to start writing. [I have] a really robust outline, which is pretty intricate. But now the standards for my outlines are higher. I need to know I've won already. I'm almost there but I'm not quite there." In April of 2017, Shyamalan announced the official title, release date, and returning actors for the third movie. The film, titled Glass, will be released January 18, 2019 and will feature Bruce Willis, Samuel L. Jackson, Anya Taylor-Joy, and James McAvoy returning to their respective roles in the series.