In 1958, Bill Denbrough, Mike Hanlon, Ben Hanscom, Eddie Kaspbrak, Beverly Marsh, Richie Tozier and Stan Uris (who call themselves The Losers' Club) each have horrifying encounters with the creature, which takes on the shape of their biggest fears (but Its most prominent form is that of a sadistic, balloon-wielding clown called Pennywise). They are also being terrorized by the neighborhood bully, Henry Bowers, which only strengthens their bond. The Losers decide to hunt down the creature and destroy It. They eventually track It down and in the ensuing enormous battle of wills (known as the Ritual of Chüd), hurt It badly. As they proceed to flee the lair of It, they realize the power they held as a group, a common purpose to defeat that which had not only hunted them but was the cause of so many other children to die, was weakening. As they grapple with their fear of being lost underneath the underground paths of Derry, Beverly comes up with an idea that would bind them together for the possible return of It. Under the protest of her male friends, she proceeds to have sexual intercourse with each of them as a way to strengthen the bond between them. Afterwards, as they have made it outside, the Losers promise that if It ever comes back, they'll confront It again.
The narrative jumps forward to 1985, where murders are once again taking place in Derry. Mike Hanlon, the only one of the Losers who has remained in Derry, is convinced that the creature has returned and calls each of the Losers, reminding them of the promise they made as children. Each of the six other Losers have gone on to success and wealth, but had completely forgotten about their childhood trauma. They all return except for Stan Uris (who kills himself after receiving Mike's phone call) and begin piecing together their hazy memories. They also each have encounters with It.
It decides to use Henry Bowers (who had followed the Losers and also encountered It in 1958), who is now committed to the Juniper Hill Asylum, to help kill the Losers. Bowers tracks them down and seriously hurts Mike. The five remaining friends then make their way into the sewers once again to confront and destroy the creature for the last time..
The seven Losers are the children who are united by their unhappy lives, their misery at being the victims of bullying by Henry Bowers and their eventual struggle to overcome the eponymous 'It'. They are clearly characters in the King tradition of sympathetic, plausible heroes who find themselves caught up in an evil they cannot quite comprehend but with which they must battle.
William 'Stuttering Bill' Denbrough: Also known as "Big Bill". His brother George was murdered by It in 1957. Bill feels slightly guilty of the murder, because he'd been the one who sent George outside to play, where he died. Ever since George died, Bill has been partially ignored by his parents. Beverly Marsh develops an intense crush on him during their time in the losers club, and when the group return to Derry in 1985 they sleep together, but do not carry their relationship any further. He is the most determined and resourceful of the Losers, and is the one who, both in 1958 and 1985, confronts It in the Ritual of Chüd and eventually destroys It. As an adult he marries Audra Phillips, a successful actress bearing a strong resemblance to Bev. As with other King characters Jack Torrance, Paul Sheldon, Ben Mears, Bobbi Anderson, Thaddeus Beaumont, Mike Noonan, Louis Creed and numerous others, in 1985, Bill is a writer.
Benjamin 'Ben' Hanscom: He was dubbed "Haystack" by Richie, after the professional wrestler Haystacks Calhoun. Because of his weight, he has become a frequent victim of Henry Bowers, who once used a buck knife to try to carve his name into his stomach (he managed an unfinished 'H' before Ben escaped). He also develops an intense crush on Beverly Marsh, and the two get together after the 1985 defeat of It. In later life, he becomes a successful architect and loses his excess weight. His building skills become useful to the Losers, from making two silver slugs to an underground clubhouse where Mike and Richie have a vision of Its cosmic crash into the site which would later become Derry, Maine.
Beverly 'Bev' Marsh: The only female in the group, Beverly is a pretty redheaded girl from the poorest part of Derry and has an abusive father (referred to as her stepfather at one point in the novel) who beats her regularly. She develops a crush on Bill Denbrough and her skill with a slingshot is a key factor in battling It. The boys are described as being fond of Beverly; all of them at some point have romantic or sexual feelings for her. As an adult, she becomes a successful fashion designer, but endures several abusive relationships, culminating in her marriage to Tom Rogan, who sees her as a sex object and dissaproves of her chains smoking, using it as an excuse to beat her. After a brief reunion with Bill, she subsequently departs Derry with Ben following the death of her husband (who was nearly used by It to kill the Losers).
Richard 'Trashmouth' Tozier: Known as "Trashmouth", Richie is the Losers' most lighthearted member, always cracking jokes and doing impersonations, which prove very powerful weapons against It. He is "too intelligent for his own good", and channels his boredom in hyper-active wisecracking, to the point of being self-destructive (his flippant remark to Henry Bowers leads to his almost getting beaten up by Henry and his friends). His childhood trauma stemmed from his rapid-fire insults being compulsive and almost subconsciously triggered. He is the most devoted to keeping the group together, as he sees 7 as a magical number (besides 3), and believes the group should have no more, no less. In later life, he is a successful disc jockey. Like Ben, he has a crush on Beverly, though it isn't crucial to the plot. He has bad eyesight and wears thick glasses as a child.
Edward "Eddie" Kaspbrak: Eddie is a frail hypochondriac whose asthma is psychosomatic. He has a worrying, domineering mother who, ever since his father died, has used Munchausen Syndrome by Proxy to bully him into caring for her. Eddie is easily the most physically fragile member of the group. Richie calls him "Eds", which he hates (as is demonstrated when It bites off Eddie's arm and his dying words are to Richie, who calls him "Eds": "Richie, don't call me Eds. You know I...I... [without finishing his sentence, "I hate it when you call me that"]"). He is a Methodist. When Henry and his friends break his arm and his mother tries to prevent the Losers from visiting Eddie in the hospital, he finally stands up to his mother and tells her that he is no longer the helpless kid she thinks he is. He eventually runs a successful limousine business, but is married to a woman very similar to his mother. He is eventually killed by It in the final struggle after using his inhaler to wound It, making him the only direct adult victim of It (all others were killed indirectly). He also finds the strength to defend himself from Henry Bowers, eventually killing him with a broken bottle. He bleeds to death in the sewers after his arm is bitten off, ultimately dying in the gang's arms.
Michael 'Mike' Hanlon: Mike is the last to join the Losers, when he is racially persecuted by Henry Bowers. The Losers fight back against Bowers in a massive rock fight. Mike is the only one of the Losers to stay behind in Derry, and he is the town librarian who calls the others back when the killings begin again in 1985. His father kept an album filled with photos which were important to Derry's history, including several of Pennywise, the Dancing Clown. Through the knowledge he acquires of Derry, and It, he becomes an amateur historian of the town. He is seriously wounded by Henry Bowers and nearly dies as Henry hits an artery in his leg. He manages to seriously wound him driving him off (Henry's wounds allow Eddie to finish him off later) and calls 911 managing to get help over Pennywise's attempts to block him. In the hospital a nurse controlled by It tries to kill him but the other Losers share their energy with him and he manages to defeat him. He later recovers from his wounds but like the others starts to lose his memory of the experience.
Stanley 'Stan' Uris: Also known as "Stan the Man". Stan is a skeptical, bookish Jewish member of the group (Uris does, however, admit that his family take a relaxed approach to their faith, rather than practicing it devoutly). Logic, order and cleanliness are deeply ingrained in his psyche. He is the least willing to accept that It actually exists, and relies on logic more than anything else. Stan, much like Mike, is racially persecuted by Henry. As a kid, his main hobby was birdwatching. He later becomes a partner in a large Atlanta-based accounting firm. However, inkeeping with his being the character least able to accept the supernatural and the non-rational, he commits suicide by slitting his wrists and writing "IT" with his own blood, while taking a bath, upon receiving Mike's phone call, rather than return to Derry to face the ancient terror, despite being the one to slice the Losers' palms in a blood oath.
George Denbrough: The first character introduced in the book, George is Bill's younger brother. He is a stereotypical child, innocent and curious. He is killed when It, appearing as Pennywise, rips off his arm. George's death is the first in the fall of 1957 and it is what drives Bill to defeat It. Although in 1958, It threatens to appear to Bill as George, It never does so until 1985 (excluding Its appearance before Richie and Bill in Georgie's room; when it springs from the canal in a photo wearing Georgie's face), in the sewers. When Bill sees It as George, he works through his grief and overcomes Its ruse.
Henry Bowers: The sadistic, psychopathic neighborhood bully who torments the Losers, both in childhood and adulthood. Henry is shown to be a hateful and violent boy, racist and outwardly homophobic—in spite of that, however, he allowed Patrick Hockstetter to masturbate him, after which he called Patrick a 'faggot'. His father is an alcoholic, who claims to have fought in the Battle of Iwo Jima, even going so far as to buy a katana from a bartender. Oscar "Butch" Bowers is portrayed as insane, blaming the Hanlon family, the only black family in Derry, for all his problems. As a child he chases the Losers into the sewers with Vic Criss and Belch Huggins. The latter two die at the hands of It and Henry goes completely insane. Soon after he was incarcerated in an asylum after killing his father, then being held responsible for the child murders. Years later, he is driven by It to try to kill the Losers. He fails to do so and is killed by Eddie Kaspbrak with a broken bottle after wounding Mike and being seriously wounded by him in turn (Eddie admits that he wouldn't have been able to kill him if Mike hadn't wounded and weakened Henry so badly first).
Audra Phillips: Bill Denbrough's wife in 1985, Audra is a famous actress. She and Bill have an occasional working relationship: she is set to star in an adaptation of a novel he wrote. When Bill leaves for Derry, he strongly urges Audra to remain in England, and although she agrees, she leaves the next day to follow him. When she makes it to Derry, It uses Tom Rogan to capture her, and uses her as bait to lure Bill Denbrough. When the Losers defeat It once and for all they rescue Audra, but she is catatonic. The book ends with Bill using the last of his childhood to bring her out of the coma. Audra has a strong physical resemblance to the adult Beverly Rogan.
Tom Rogan: The abusive husband of Beverly Marsh. Tom has a very predatory view of women, and he thrives on the control he has over his vulnerable wife. When Beverly tries to leave for Derry, he refuses to let her, whipping her. Tom is surprised when the normally docile Beverly fights back, and almost kills him, before leaving for Derry. Tom, desperate to find his wife, beats one of her friends until he finds out that Beverly is in Derry. Tom goes to Derry with the intent to kill Beverly, and possibly her "writer friend" Bill Denbrough, whom Tom (correctly) assumes she is sleeping with. When he gets there, It uses Tom to capture Audra Phillips and bring her to Its lair under the city. Upon seeing It in Its true form, Tom drops dead in shock.
Patrick Hockstetter: A sometimes friend of Henry Bowers, who is described as being either close to or being a psychopath before he died who captures and kills animals. When he was 5, he suffocated his infant brother with a pillow. He believes he is the only 'real' human. The novel portrays him as (most likely) bisexual. One of his teachers remembers he fondled the girls in his class. Beverly had witnessed Patrick masturbating Henry Bowers and himself then offered oral sex with Henry. Henry, afraid Patrick would tell people, said he would tell everyone about Patrick keeping animals in a refrigerator to watch them die. Patrick is eaten by It after opening the abandoned refrigerator and being attacked by flying leeches that were inside, the only thing he was afraid of. The name Patrick Hockstetter was used first in Stephen King's novel Firestarter.
Reginald "Belch" Huggins: Gaining his nickname from belching, he is one of Henry Bowers' friends and helps torment the Losers. He is always with Vic and Henry in the novel. He and Victor Criss follow Henry Bowers into the sewers in pursuit of the Losers, there they encounter It as Frankenstein's Monster. It kills Vic and then goes after Henry, but Belch defends him by attacking It. However, Henry leaves Belch to fight It alone, though It easily overpowers him and tears half of his face off. He is also a very good baseball batter (when the ball is thrown slow), works for the Weekly Shopper delivering papers and had a dead father.
Victor "Vic" Criss: One of Henry's friends, and a skilled baseball pitcher. He has a knack for making malicious jokes which usually involve the word "fucking" or violence. Among Henry's gang, Vic and another friend of Henry's, Peter Gordon are the only ones who know about Henry's deteriorating sanity. He is the only member of Henry's gang to retreat when it becomes clear the Losers' Club will win the rock fight between the two groups. He, along with Belch, follow Henry into the sewers in pursuit of the Losers. They are both killed by It. Vic is cognizant of how deranged Henry truly is (it is even recalled that Vic comes to the Losers later at Tracker Brothers and tells them as much point blank, though this was never illustrated), and comes to realize that he is going insane, mostly because of the trio Vic is the only one with clearly defined morals. His head is ripped off by It, posing as Frankenstein's Monster, who's creator in the 1931 movie ironically shared his first name.
Eddie Corcoran: A boy who lives in Derry. His younger brother Dorsey is killed by their abusive stepfather with a Scotti recoilless hammer. Although he did not know his stepfather killed Dorsey, he suspects It. Eventually, he runs away to escape his stepfather. He is killed by It (first taking the form of Dorsey, then the Creature from the Black Lagoon) by decapitation. His stepfather is framed for his murder by It and kills himself many years later after seeing Eddie dead. Eddie is the only child who is actually shown getting killed by It other than George Denbrough and Patrick Hockstetter.
Moose Sadler: a semi-retarded high school student sometimes seen with Henry's gang. Joined in tormenting Mike Hanlon, who's father worked on the Hanlon family farm. After the Rock Fight he is seen once more when he, Henry, Vic, Belch and Patrick break Eddie's arm, though he seems to be more of a friend of Belch and Vic rather than Henry and Patrick. His name comes from the character from the Archie comics. It is somewhat implied that he dies in the summer of 58 as the Losers later reminisce that all of Henry's friends are ultimately killed by It.
Peter Gordon: A rich kid from West Broadway that is the boyfriend of an unnattractive girl named Marcia Fadden and a sometimes member of Henry's gang. He invites (menacingly) Ben to play baseball in 1958 and while on a date with Marcia insults the Losers at the movies. Like Vic Criss, Peter also realizes how crazy and insane Henry is. He joins Henry in tormenting Mike and briefly enters the rockfight, being the first to surrender and take leave. It is implied that It kills him later that summer as the Losers recall that all of Henry's friends (and ex-friends) were killed by It.
Richard "Dick" Hallorann: A chef in Derry Army E Company. Although Dick Holloran plays a minor role in this novel by saving Mike Halon's father at the fire at the Black Spot, he later plays a more significant role in the novel The Shining.
William Hanlon: Mike Hanlon's father. At a young age, William joins the Derry regiment of the National Army. He soon comes to realize that there is a deep racial divide within the army and within Derry (although he does admit that there is a large amount of good citizens in Derry as well as bad, and it might actually be the place itself that causes such divides between its people). This led to the fire at the Black Spot, a renowned bar made by the outcast African American Soldiers. As the bar becomes more popular the governing bodies of Derry become jealous of the fame that has become of the Black Spot bar. This then leads to the fire at the Black Spot, started by the Legion of Decency (the equivilaent of the Ku Klux Klan), although William believes the fire to be a hoax that got out of control. After escaping the inferno, William witnesses It seizing a member of the Legion of Decency. It was in the form a giant bird that was "hovering" over the crowd. It was hovering by using balloons attached to each wing to float over the crowd. He died of cancer in 1962, four years after The Losers defeated It for the first time.
Alvin Marsh: Father to Beverly Marsh. Although he is not an alcoholic or drug-user, he abuses Bev and her mother, and acts mysogenistic. However, there are times when Al is shown to be a loving and caring father to Bev. He died of unknown causes in 1980 (possibly killed by It).
Publishers Weekly listed It as the best-selling book in America in 1986.
The story was adapted into a film in 1990. It is a four-hour long miniseries that was praised for the acting of the young Losers and Tim Curry as Pennywise, but was criticized for its dragging pace and special effects at the ending, which many consider a "letdown".
As of June 7th, 2012, a 2-part remake is being made by Cary Fukunaga.