Self-insertion is a literary device in which the author writes themself into the story as a fictional character.
Forms
In art, the equivalent of self-insertion is the inserted self-portrait, where the artist includes a self-portrait in a painting of a narrative subject. This has been a common artistic device since at least the European Renaissance.
Similar literary devices include a first-person narrator, an author surrogate, and a character somewhat based on the author, whether the author included it intentionally or not. Many characters have been described as unintentional self-insertions, implying that their author is unconsciously using them as an author surrogate.
"X-insert" or "reader-insert" fiction has the reader appear as a character in the story; their name is substituted with "you" or "y/n" ("your name").
Mindy Kaling has been accused of using self-insertion in her movie roles.
Criticism
Self-insertion has been criticised as a writing device as being unoriginal.
Examples
Money by Martin Amis
The Razor's Edge by Somerset Maugham
Slaughterhouse-Five by Kurt Vonnegut
Breakfast of Champions by Kurt Vonnegut
The French Lieutenant's Woman by John Fowles
Stan Lee in different Marvel comic books and movies
Clive Cussler, author of Dirk Pitt novels, has inserted himself as a deus ex machina character in several of his books. Gargantua and Pantagruel by François Rabelais, in the chapter "How Pantagruel with his tongue covered a whole army, and what the author saw in his mouth" Milton: A Poem in Two Books by William Blake The Divine Comedy by Dante Alighieri Randolph Carter in H.P. Lovecraft tales The title character of the Rush Revere series by Rush Limbaugh Bella Swan in the Twilight novel series by Stephenie Meyer Rayford Steele and Buck Williams in the Left Behind novel series by Tim LaHaye and Jerry B. Jenkins The title character of Jane Eyre by Charlotte Bronte I am the Messenger by Markus Zusak Homestuck by Andrew Hussie JPod by Douglas Coupland The Dark Tower VI: Song of Susannah by Stephen King Handbook for Mortals by Lani Sarem A Series of Unfortunate Events by Lemony Snicket The Map and the Territory by Michel Houellebecq Frank Owen in The Ragged-Trousered Philanthropists by Robert Tressell Robert Langdon in the Robert Langdon book series by Dan Brown John Barth in the Dunyazadiad segment of John Barth's novel Chimera. Rohan Kishibe in Diamond Is Unbreakable by Hirohiko Araki Louis in the Wayside School series by Louis Sachar Rudyard Kipling in The Man Who Would Be King by Rudyard Kipling The Thin Clergyman in The Railway Series by The Rev. W. Awdry