Fourth Wall Shut in Story

Subtrope of Trapped in Another World, but the hero has intimate knowledge of the world he's in... because he's the one that created it, perhaps moreso a variation of Pygmalion Plot. For this to have conflict, however, not everything is as it appears, he no longer has author...ity, or he didn't realize the problems he was creating, and is as bound to the rules of the world as those he created. The author might be seen as a god of his own world, and worshiped for it, or hated for the problems he made.

Related to Trapped in TV Land.

Film

 * The Adventures of Sharkboy and Lavagirl in 3-D. Max creates Planet Drool and its inhabitants in his imagination and records the information in his dream journal. The villain steals the dream journal, uses it to make the world come into existence and takes control of it. Max has to go to Planet Drool on a quest to stop him.
 * Delirious, a 1991 film: John Candy plays a Soap Opera writer who get trapped in his own series, but he can use his typewriter to edit the events the way he wants.
 * Mirror Mask
 * Monkeybone

Literature

 * Kurt Vonnegut's Breakfast of Champions: The character Kilgore Trout is supposed to be a stand-in for Vonnegut, and toward the end of the story, Trout has conversations with Vonnegut (who is the third-person omniscient narrator). The content of these conversations is Trout (fictional) demanding changes to his world from Vonnegut (real), but the underlying subtext is of Vonnegut (real), in futility, demanding impossible changes to his own life.
 * The Inkworld Trilogy: The main characters are simply fans of the story, but the author himself got trapped in his own writing, too. He wasn't doing too badly there... for a time.
 * In Pamela Dean's Secret Country trilogy, a group of young cousins create a fantasy world together and end up stuck there for real.
 * Typewriter in the Sky has a related problem where an author bases a character in his new novel on a friend, and the friend gets sucked into the novel and forced to play the role of the character.

Live Action Television

 * This is the trap in The Land of Fiction in the Classic Doctor Who serial The Mind Robber. Defeat the (supposed) Big Bad by writing yourself into a story as the hero.

Music

 * The music video to the song "Take on Me" by A-ha illustrates this, with a much more carefree attitude than usual. Given its medium 1980s pop music, carefree is to be expected.

Newspaper Comics

 * This was the kickoff for a Wizard of Oz parody in Dilbert once.

Video Games

 * Classic old-school platformer Comix Zone (yes, it's from back when Xtreme Kool Letterz was in vogue), about an artist who gets dragged into a comic book he's writing, and has to take the place of the hero in order to stop the villain who dragged him in there, and who hopes to take the artist's place in the real world by killing him.
 * The director Captain Blue of Viewtiful Joe fits this trope when he gets trapped in the Movie Land he had filmed. Although he isn't the hero of the actual video game.

Web Comics

 * Avallanath is a webcomic about a writer of thick fantasy novels who has long since succumbed to hackdom being summoned (along with several thousand fans) to the fantasy world so the characters can get their hands on him.