Reality Writing Book

What if you start reading a book and suddenly realize that the book is about you! This has got to be some joke, right? But then how could whoever have done this have known that you would read the section which says you are in the cafeteria reading the book under a table, at the exact time you were doing just that? And now it's talking about what you're contemplating at this very moment, and this blows your mind.

Don't worry, variations of this happen a lot and it seems like Reality Writing Books are everywhere. There are three main types:

Type 1 : Your Fate Is Already Decided
The book already seems to be completely written and appears to have predicted your every move. This may double as a Tome of Fate, depending on whether the book itself is magic (which would qualify under this trope), or someone else merely wrote such things in a more or less standard book (which would not qualify). Sometimes events written in the book turn out to be wrong, or able to be changed by the character's reaction to the information the book provides.

Type 2 : Automatic Data Recorder
The book writes itself as you read it, observing rather than predicting your movements. It may contain information merely about what happens around the book itself or things which are pertinent to the plot of the story. Often these books also have some form of omniscience, and have things written in them that the protagonist could never have known about ("Little does Alice know, that Bob is sneaking up behind her at this very moment!"). The words might literally appear on the page before your eyes, or as you turn the last page written on there might mysteriously be a next one.

Type 3 : Choose Your Own Adventure
The book must be written in, and the things you write about start happening. There may be certain rules attached to this version, or not everything you write will happen, it might be random chance which elements your write down come to pass.

Keep in mind this isn't always a book. Online material or videos and such are growing more popular to use as such items.

Compare Tomes of Prophecy and Fate, Brown Note, Rewriting Reality and Reality Warper

Anime and Manga

 * The Death Note is a book that when you write someone's name in it, they die. If you write in how they are to die, provided it's feasible they will die in that manner and time, otherwise they die of a heart attack by default.
 * Mirai Nikki features journals which contain the future entries of characters, allowing them to see what they'll experience in the future, and react to them. The journals change as they do things. Most of these journals take the form of diaries entered into cellphones, though one woman has hers on a scroll.
 * Cardcaptor Sakura: The Create Card is a Reality Warper book that makes everything written in it materialize.
 * 'Fushigi Yuugi has "The Universe of the Four Gods", which is type 2. While Miaka and Yui continue their adventure, people in our world can read, what is happening in this moment in Four God's dimension.
 * Zetta becomes a type III book in Makai Kingdom.

Comicbooks
"Destiny continues to walk... He is holding a book. Inside the book is the universe."
 * The Sandman: Destiny, the eldest of the Endless, only intervenes when the Book of Destiny tells him to.


 * The Awesome Comics mini-series Youngblood Judgment Day, written by Alan Moore, revolved around a mystical book. Anything written in this book became reality.
 * In the Dragon Magazine comic Libram X, the eponymous tome is both the accurate self-writing log and can be written (one magic quill is included in the kit). Which naturally explains why everyone and their dogs tried to find it all this time.
 * Once In a Blue Moon has sort of a timey-wimey twist: Aeslin goes back to Avalon because of something she sees about to happen in the magic book, but the writer of the book in Avalon doesn't write that part until after it happens.

Films -- Live-Action

 * In Stranger Than Fiction, the protagonist finds out that unwittingly by all involved, he's the main character of a book currently being written by an author famous for killing off her characters.
 * The Neverending Story features The Neverending Story, a magic book that dictates what is happening in the world of Fantasia and the main character, who is initially reading the book on earth.
 * An example of a video rather than a book. Spaceballs has the evil characters discovering the video of the movie they are starring in--at one point their actions both in the film universe and the video are perfectly synched up ("Sir, you're looking at now now"), to the characters' bemusement.

Literature

 * In the Land of Oz Glinda the Good Witch of the South has a book in which is written everything that happens in Oz, as it happens. If she needs to find out what happened at any given time she just looks it up.
 * The Book of Three from the Chronicles of Prydain.
 * In Discworld death has an entire library of books that write themselves as people's lives unfold.
 * In Edward Eager's Seven Day Magic, the children find a magic book that not only lets them wish themselves into other books, but also records everything that happens to them as it happens. And whenever anyone else picks it up, it appears as whatever book they would most like to read.
 * Inkheart had a variation: Meggie and Mo can read things (and people) in and out of books. In Inkspell,
 * Young Wizards has The Book of Night With Moon.
 * The eponymous book in The Neverending Story, the basis for the film mentioned above.

Live-Action TV
"Sam is doing laundry as Dean sits nearby, reading from Chuck's latest manuscript.
 * Supernatural: Chuck the Prophet writes books about two characters he thinks he made up named Sam & Dean Winchester, who have lives identical to the real Sam & Dean. At some points what he writes lines up with what's happening to Sam & Dean at that exact time. Like this scene in the laundromat:

Dean: I'm sitting in a laundromat, reading about myself sitting in a laundromat reading about myself... My head hurts.

Sam: There's got to be something this guy's not telling us.

(Sam turns to toss his darks into the machine. Dean continues reading.)

Dean: "Sam tossed his gigantic darks into the machine. He was starting to have doubts about Chuck, about whether he was telling the whole truth."

Sam:Stop it.

Dean: "'Stop it,' Sam said." Guess what you do next. (Sam turns away, scowling.) "Sam turned his back on Dean, his face brooding and pensive." I mean, I don't know how he's doing it, but this guy is doing it. I can't see your face, but those are definitely your "brooding and pensive" shoulders. (Sam sighs, exasperated. Dean looks down at the manuscript.) You just thought I was a dick.

Sam: (turns around looking impressed.) The guy's good."


 * Lost Girl has the Blood King's book with which he can alter reality if he writes in it with his own blood.
 * The X Files had an episode where a writer moves in to Scully's apartment building and starts affecting her life with his writing. He also.
 * The Xena: Warrior Princess episode "The Quill Is Mightier..." features a magic scroll that causes whatever is written on it to become reality. The scroll tends to be something of a Literal Genie.

Tabletop Games

 * In a variant, Azalin from the Ravenloft setting has a library containing the self-writing biographies of everyone who lives in his domain of Darkon or visits it for more than a few weeks. These accounts contain their subjects' true histories, even if the actual people have forgotten this same information due to Darkon's nature as a Fisher Kingdom. (As destroying someone's biography causes their stolen memories to return, it's implied that the books are actually draining visitors' memories right out of their heads.)

Videogames

 * Professor Layton VS Ace Attorney seems to have such book(s).
 * Maxwell's notebook from Scribblenauts is a type 3. It's able to summon pretty much anything written into it. Including itself (which results in a notebook that spawns random items when you use it)
 * The book in Avalon Code is roughly this. It's meant to record everything in the world, but you must record everything manually by slamming the book on top of them, whether they're a person, a monster or an inanimate object. You can play mix-and-match with some of their attributes to weaken or strengthen them (making monsters easier or harder to fight) and do other tweaks.
 * Makai Kingdom. The Sacred Tome predicts the future with absolute certainty, and whatever is written in it BECOMES the truth. 'Badass Freakin' Overlord' Zetta is pissed off because the tome claims that he will destroy his own Netherworld through foolishness and arrogance, so he burns it. This causes the entire world to collapse, and he has to quickly transform HIMSELF into the Sacred Tome to prevent a total collapse, though his own Netherworld still bites it, thus proving the prediction true... Most of the gameplay basically centers around using the powers of the Zetta-Tome, by having various characters write 'wishes' into it, thus making them come true.
 * Wizardry Dark Savant Trilogy (VI, VII, 8) has the Cosmic Forge, a pen and Tome Of Fate. Anything written in it will become true, albeit not as the writer expects. If written pages are torn out, history itself will be Ret Conned. One of the endings in 8
 * Gran Grimoire from Final Fantasy Tactics Advance has changed entire town into fantasy kingdom.
 * Luso Clemens from Final Fantasy Tactics a 2: Grimoire of the Rift has Type 2 / Type 3 book (Grimoire of the Rift) that writes itself, recording Luso experiences. It was also used to travel between worlds.
 * A non-book example happens in Persona 2: rumors become true if enough people hear about them (this is due to a demon dicking with humanity.) No writing needed, just word of mouth. Mostly this results in Urban Legends becoming true, but at one point the player characters themselves take advantage of it.

Western Animation

 * One of these appears in a later episode of Jackie Chan Adventures, when it's rewritten by Shendu. Luckily Jade is left unaffected since she manages to tear out the page that relates to her, leaving her unaltered.
 * Sabrina the Teenage Witch: Sabrina finds a typewriter in the attic. The short story she writes is Type 3.
 * On Regular Show forging the park records has this effect. Mordecai and Rigby do it to trick Benson into giving them a raise, but Rigby overdoes it, resulting in the park being attacked by a snow monster.