Types of story arcs: Vonnegut's shapes of stories and the six arcs found in 1,327 novels

What is a story arc?

A story arc is the shape a story's fortunes trace from beginning to end: how much better or worse things get for the protagonist, and when. If you plotted the hero's luck chapter by chapter, the line you would draw is the arc. A character arc is related but narrower: the inner change of one person, which usually travels with the story arc.

Writers have drawn these shapes for a long time. Gustav Freytag diagrammed the five parts of a tragedy in 1863; Kurt Vonnegut sketched stories as curves on a chalkboard; and since 2016 researchers have measured arcs in thousands of books with sentiment analysis. Each view answers a slightly different question, and together they make a practical planning tool.

Sources: Gustav Freytag, Technique of the Drama, trans. Elias J. MacEwan (Internet Archive) · Maria Popova, "Kurt Vonnegut on the Shapes of Stories", The Marginalian (2012) · Reagan, Mitchell, Kiley, Danforth & Dodds, "The emotional arcs of stories are dominated by six basic shapes" (arXiv:1606.07772)

What did Kurt Vonnegut mean by the shapes of stories?

Kurt Vonnegut studied anthropology at the University of Chicago. According to the university's own news publication, Vonnegut's master's thesis was rejected and Vonnegut left to work in public relations; decades later the university accepted the novel Cat's Cradle as the thesis and awarded Vonnegut an A.M. in 1971. In Palm Sunday, as quoted by Open Culture, Vonnegut recalled the thesis idea as stories having shapes that can be drawn on graph paper, and said the committee turned it down because it was "so simple and looked like too much fun."

In the lecture version, the vertical axis runs from good fortune to ill fortune (Vonnegut's G–I axis) and the horizontal axis from beginning to what Vonnegut labelled "E for entropy." A transcript of the lecture and the hand-drawn graphs appear in Vonnegut's essay collection A Man Without a Country (Seven Stories Press, 2005), in the chapter on creative writing.

The shapes Vonnegut drew include Man in Hole, where somebody gets into trouble and gets out of it again; Boy Meets Girl; Cinderella, a rise, a sudden drop at midnight and a climb to happiness; and Kafka, which starts low and ends lower, with a man who has turned into a cockroach. Vonnegut also drew Hamlet, noting that its situation resembles Cinderella's with the sexes reversed.

Sources: University of Chicago Chronicle (2007) on Kurt Vonnegut's rejected thesis and 1971 A.M. · Open Culture, "Why the University of Chicago Rejected Kurt Vonnegut's Master's Thesis" (2019), quoting Palm Sunday · Kurt Vonnegut at the blackboard, lecture transcript via 3 Quarks Daily (credited to Lapham's Quarterly) · Maria Popova, "Kurt Vonnegut on the Shapes of Stories", The Marginalian (2012) · Kurt Vonnegut, A Man Without a Country (Seven Stories Press, 2005), Open Library record

What are the six types of story arcs?

The six types come from "The emotional arcs of stories are dominated by six basic shapes" by Andrew J. Reagan, Lewis Mitchell, Dilan Kiley, Christopher M. Danforth and Peter Sheridan Dodds (EPJ Data Science, 2016). The team took 1,327 English-language fiction books from Project Gutenberg, kept those between 20,000 and 100,000 words with more than 40 downloads, and scored the sentiment of 10,000-word windows slid through each text using the Hedonometer's labMT word list.

Three approaches (matrix decomposition, supervised learning and unsupervised learning) converged on the same six core shapes. Longer, more complex stories combine them, for example two Man in a hole arcs in a row.

Sources: Reagan, Mitchell, Kiley, Danforth & Dodds, "The emotional arcs of stories are dominated by six basic shapes" (arXiv:1606.07772) · Reagan et al., EPJ Data Science 5, 31 (2016), DOI 10.1140/epjds/s13688-016-0093-1

Which story arcs are most popular with readers?

Reagan's team compared shapes against Project Gutenberg download counts and found that Icarus, Oedipus and two Man in a hole arcs in sequence were the three most successful. The most common shapes were not the most downloaded. The authors are careful to say downloads are "only a rough proxy for success."

A larger study points the other way. Ryan Boyd, Kate Blackburn and James Pennebaker analysed about 40,000 traditional narratives, including novels and film scripts, for "The narrative arc" (Science Advances, 2020) and reported no evidence that following a normative story structure was related to a story's popularity.

Read together, the studies suggest a shape is a tool rather than a formula. Pick the arc that matches the experience you promise readers, such as relief after a long hole or the dread of an Icarus rise, and spend your effort on the specific turns.

Sources: Reagan, Mitchell, Kiley, Danforth & Dodds, "The emotional arcs of stories are dominated by six basic shapes" (arXiv:1606.07772) · Boyd, Blackburn & Pennebaker, "The narrative arc: Revealing core narrative structures through text analysis", Science Advances 6(32), 2020

How do story arcs relate to Freytag's pyramid and the narrative arc?

In Die Technik des Dramas (1863; translated into English as Technique of the Drama by Elias J. MacEwan in 1894), Gustav Freytag described the "pyramidal structure" of a drama in five parts: introduction, rise, climax, return or fall, and catastrophe. Freytag also named three moments that move it: the exciting force that starts the action, the tragic force that turns it, and the force of the final suspense that delays the end. Freytag charted rising and falling action in tragedy, not the hero's luck, but in the tragedies Freytag studied the two often move together, which gives an Icarus-like shape.

Boyd and colleagues measured a different kind of arc from word use. Across their corpus, staging words (setting the scene) are highest at the start and then drop; plot-progression words start low and climb; and cognitive-tension words, the language of thinking through a problem, peak in the middle. In practice, that means the middle of most stories is where characters deliberate about the conflict, whatever the shape of their fortune.

Sources: Gustav Freytag, Technique of the Drama, trans. Elias J. MacEwan (Internet Archive) · Boyd, Blackburn & Pennebaker, "The narrative arc: Revealing core narrative structures through text analysis", Science Advances 6(32), 2020

How do you plan a story arc, step by step?

You can turn any of the six shapes into a chapter plan in a few passes. The example table shows one original premise planned three ways, to show how much the shape changes the book.

1. Decide where the protagonist's fortune ends compared with where it starts: higher, lower or back where it began.
2. Choose the shape that gets there. One turn gives Man in a hole or Icarus; two turns give Cinderella or Oedipus.
3. Place the turns first. For two-turn shapes, put the second turn late enough that the final movement still needs several chapters.
4. Score each planned chapter from -3 to +3 for the protagonist's fortune, and write one sentence on why it rises or falls.
5. Put the hardest decision in the middle, where readers expect characters to wrestle with the conflict.
6. Plot the scores. If the line is flat for several chapters, add a reversal; if it zigzags without direction, cut a turn.

How can you plan a story arc in AIBookCraft?

AIBookCraft's free plot generator returns a logline and five beats: Opening, Disruption, Midpoint turn, Crisis, and Choice and ending. Score each beat for the protagonist's fortune and you can see which of the six shapes you have; if the Crisis and the ending point the same way, decide whether you want an Icarus fall or need one more turn. The tool also lets you choose a story shape such as Quest, Mystery, Relationship, Survival or Transformation, which describes the kind of plot rather than the emotional curve. No account is needed.

When the plan works, a free account saves it and lets you write and edit chapters yourself; Pro adds AI chapter drafting that follows the plan. The iOS and Android apps, listed as "AI Book Writer Story Maker" on the App Store and "AI Book Writer Story Generator" on Google Play, use the same account. Check each AI chapter against the fortune score you planned for it.

Sources: AIBookCraft free plot generator · AIBookCraft product facts · AIBookCraft web plans