The terror, which would not end for another twenty-eight years -- if it ever did end -- began, so far as I know or can tell, with a boat made from a sheet of newspaper floating down a gutter swollen with rain.
IT is a 1986 horror novel by American author Stephen King. The story is about seven children being terrorized by a malevolent monster - known only as IT - that takes the form of their deepest fears but primarily appears in the form of a clown, calling itself "Pennywise the Dancing Clown." The novel features a nonlinear narrative which alternates between two different time periods and shifts among the different perspectives and stories of its seven protagonists. It deals with themes which would eventually become King staples: the power of memory, childhood trauma and the ugliness lurking behind a small-town façade.
One of the most popular Stephen King novels and widely regarded as a horror classic, It is also one of the darkest and most frightening, its subject matter being a child-killing supernatural monster with Adults Are Useless in effect for at least half the story. Along with The Stand it is one of the stories that cemented King's reputation as the premier modern horror writer.
In 1990, the novel was loosely adapted into a television movie featuring John Ritter as Ben Hanscom, Harry Anderson as Richie Tozier, Tim Reid as Mike Hanlon, Annette O'Toole as Beverly Marsh, Richard Thomas as Bill Denbrough and Tim Curry as Pennywise in a career-defining role.
On March 12, 2009, Warner Bros. announced that the production of a remake of IT had started. Dan Lin, Roy Lee and Doug Davison are set to produce.
Not to be confused with the 1927 silent film of the same name, which introduced the phrase "It Girl" to the world. Or the Big Bad of A Wrinkle in Time. Or the guys down in the sub-basement who run the All The Tropes Server. We hope.
- Abusive Parents: A short list: Beverly's father, Henry's father, Tom Rogan's mother, Eddie Corcoran's stepfather and Eddie Kaspbrak's mother (even if she didn't mean it that way).
- Adults Are Useless / Invisible to Adults: Justified, and averted when necessary.
- Anatomically-Impossible Sex: The sewer scene. A glance at a medical textbook can tell you that, while it is possible for prepubescent boys to reach climax, it is extremely painful, as their reproductive organs are not fully developed and working.
- Asshole Victim: Henry's friends, Henry, and Tom Rogan in that order.
- Axe Crazy: Claude Heroux.
- Batman Gambit: It is vaguely implied that the so-called Other had a hand in bringing the Losers together and infusing them with the courage necessary to face the Spider. That they forget about their friendship after finally killing it seems to ratify the Other used this bond to its breaking point without having them all go mad.
- Big Good: The Turtle in the book.
- Bittersweet Ending: IT is finally defeated and vanquished, but two of the Losers' Club members are dead, most of their hometown is destroyed by a flood with IT's death and the surviving members' memories slowly fade away until they completely forget about each other, but somehow they know that they will be friends forever.
- And some of King's later works imply that IT is Not Quite Dead after all. IT can never truly be destroyed.
- Bloodless Carnage mixed with Getting Crap Past the Radar: Since the movie version was made for television, most of the actual deaths weren't shown in very graphic detail. Most instances in which the filmmakers were allowed to include blood took place during It's illusions, in which it bursts from balloons, erupts from a sink, and spills from containers, but never leaves a human body or is referred to as such. The idea that it even is blood is up to audience assumption.
- Brown Note: The "deadlights", IT's true form, can cause whoever sees them to go insane.
- The Cameo: Christine shows up to give Henry Bowers a lift.
- Dick Halloran of The Shining fame also shows up in Will Hanlon's story of how the future cook of the Overlook hotel saved him from the Black Spot fire.
- The 1930s flashback includes an appearance by Walter Pickman, from the H.P. Lovecraft story Pickman's Model.
- Pennywise appears in other Stephen King novels featuring Derry, and is even mentioned in the Dark Tower saga.
- Camp Gay: Adrian Mellon, IT's first victim in 1985.
- Catch Phrase:
- Beep beep, Richie
- I worry about you Bevvy, sometimes I worry a lot.
- B-B-B-(*beet*)-Billy Boy.
- I'll kill you all.
- Dontcha wanna balloon?
- We/they all float (down here).
- When you're down here (with us/me), YOU'LL FLOAT TOO!
- Circle of Friendship: The main characters do this to help a hospitalized main character defend himself from a Brainwashed and Crazy nurse.
- Clap Your Hands If You Believe: The Losers' use their childlike beliefs as weapons, making it so that IT can be damaged by things such as silver bullets or an aspirator.
- Did Not Do the Research: Bill's actress wife Audra is in England making a film produced by an Englishman "who had once bowled a century at cricket," which anyone who knows anything about cricket will tell you is impossible. (A rough US equivalent would be "pitching a home run".) 
- Did You Just Punch Out Cthulhu?
- Doorstopper: The book reportedly killed a chihuahua. By falling on it.
- Dream Sequence
- Eldritch Abomination: Makes Cthulhu look like a puppy the way King describes IT's true form. Not to mention all the shape shifting.
- And that's just what human beings are capable of comprehending. In the mental wars between the Losers and It, it's suggested It's true form exists beyond the boundaries of reality as all-consuming and destroying light.
- The End - or Is It?: From the first line, it's uncertain as to whether "the terror" ever really did end. In the final chapters, the possibility is noted that Ben may have missed one of IT's eggs when he was executing her offspring.
- Final Battle: Foreshadowed right from the first page.
- Gondor Calls for Aid: In the movie when IT returns and the now adult Mike calls the rest of his lucky 7 The Losers Club.
- Go Mad from the Revelation: A common reaction upon seeing It's true form.
- Harsher in Hindsight: An in universe example: "Tell Stan unless he's on his way to Derry, he's a dead man!"
- I'm Not Afraid of You
- In Case You Forgot Who Wrote It: A surprisingly rare example for a Stephen King adaptation, probably because the title on its own is extremely generic.
- Let's Split Up, Gang!: Subverted. When Bill and Richie are exploring the basement of the house on Niebolt Street, Bill starts to suggest this. Richie cuts him off with a resounding "Fuck that!"
- Limited Special Collectors' Ultimate Edition: Cemetery Dance released one for the novel's 25th anniversary.
- Mind Rape: Pennywise is very fond of messing with the Losers Club's heads.
- Monster Clown: Pennywise, a literal monster in the form of a clown.
- Officer O'Hara: Mr. Nell, who provides the basis for Richie's "Irish Cop" Voice.
- Parental Obliviousness
- Placebo Effect: Eddie's asthma is revealed to be psychosomatic, and his medication is a placebo.
- Politically-Incorrect Villain: Pennywise himself, along with Henry and Butch Bowers.
- The Power of Friendship: One of the major themes in the book is of childhood friends who have long since gone their separate ways but must now come together to defeat the Big Bad.
- Red Oni, Blue Oni: the Spider and the Turtle. One actively hunts down and eats human children while the other just sits on the edge of forever, seeing it all happen and "helping" the Losers during their first confrontation with It. The Spider berates it for just sitting there, offering seemingly useless advice. That the Spider's eyes are described as ruby-red while the Turtle's shell is some blueish-greenish color also reinforces the trope.
- The Reveal: The revelation, in the book's later chapters, that IT is actually female. Not only that, but she just so happens to have laid a shitload of eggs...
- Ripped from the Headlines: Adrian Mellon's murder was modelled after the murder of Charlie Howard, another Camp Gay man who was thrown off a bridge in Maine; they even landed in the same river. Howard simply drowned, though; there was no demonic clown involved. Probably. Also The Brady Gang (changed to Bradley in the text), gunned down by FBI agents in Bangor in 1937.
- Sacrificial Lamb: George Denbrough and Adrian Mellon.
- Say My Name: "BEEEEEEEEEEV!"
- Somebody Else's Problem: Implied to be the doing of IT, but it can still get rather disturbing at times.
- Spooky Photographs: That start moving and threatening you.
- Spooky Silent Library: At least when Mike's working there after hours.
- Survival Mantra: "He thrusts his fists against the posts and still insists he sees the ghosts".
- Take That: In the novel, when Bill (who, as an adult becomes a very sucessful horror writer) recalls his college years, and how he crashed heads with his writing teacher, who believed that a good work of fiction also had to make a political statement, and Bill's statement that one should write good stories that entertain, since "politics change over time but stories remain".
- There Are No Therapists
- There Is No Kill Like Overkill: The execution of the Bradley gang.
- Town with a Dark Secret: More like a dark secret shaped like a town.
- Turtle Power: Hinted at throughout the book. A cosmic force, opposed to It in at least some way, is called the Turtle. It subtly guides the protagonists. And, countless æons ago, it created the universe when it got sick and threw up.
- Voluntary Shapeshifting: IT usually takes the form of Pennywise the Clown, but often assumes the shape of whatever the victim is most afraid of. Pennywise is something of a neutral form for either dealing with multiple victims or the same victim twice, or just getting around.
- Where Everybody Knows Your Flame: Parodied - it takes the guy running The Falcon years to realise that his place has become the town's gay bar, but everyone else is convinced there must be orgies going on nightly.
- Worst News Judgment Ever: Mike discovers that despite the children's killings and incidents in which many people die, those news are rarely spoken outside the town of Derry; its like something doesn't want those to be known outside.
- Would Hurt a Child: Not just hurt, psychologically torment and eat them too.
- Your Mind Makes It Real
"You don't have to look back to see those children; part of your mind will see them forever, live with them forever, love with them forever. They are not necessarily the best part of you, but they were once the repository of all you could become."
- In fairness, Bill's disparaging comments about British television are more accurate.