Exposition is a literary tool that is used to explain the setting of a work. The primary function of this device is to tell the reader what happened to the heroes and the world prior to the main events of the plot. In addition, this tool allows the writer to provide the context necessary for a better understanding of the main conflict.

The term has Latin roots and derives from the word "expositio," which can be translated as "to put on display" or "to present."

This tool is commonly mistaken for another term called "a prologue." The reason behind this confusion is that both literary devices share the same purpose – to provide background for the story. However, a prologue is always located at the beginning of the book and has a separate chapter dedicated to it. Exposition, on the other hand, can even take the form of an explanatory paragraph that can be located anywhere in the piece.

Exposition has a wide range of functions. Writers use this device when they want to describe the events that shaped the character traits and values of the protagonist. It is also added to explain the setting of the piece. This can mean either describing the heritage of a single family or town or giving context for an entire historical period or social structure.

Exposition is the introduction to the action, a short retelling of the affairs that happened before the main conflict was created, and it usually leads up to the enticing incident. This tool provides background, without which the reader will struggle to make sense of the events to come. It can be conveyed through various means, such as descriptions, inner thoughts, monologues, and dialogues.

For students and researchers, studying the exposition of a literary work allows for a better understanding of the author's intent behind the piece, as these parts of a book usually include details that will play a vital role in the plot.

Another benefit of using this device is that it makes the characters and the setting seem more realistic to the reader. When the author gives context to the heroes or the world, it creates the impression that they existed before the book began. Thus, all characters have a past that substantially determines their present actions.

This literary device is especially useful in fantasy and science fiction works. This is because authors that write in these genres create entirely new worlds that the reader knows nothing about. To familiarize the reader with the setting, the writer can dedicate several pages of exposition before adding the enticing incident.

Due to the massive size of a trilogy like "The Lord of the Rings," exposition there is presented in small portions throughout all three books. G.R.R. Tolkien uses Gandalf to give both the heroes and the reader crucial bits of historical background, as the story moves along.

The length of an exposition can vary greatly and depends on the author's idea and the size of the work as a whole. For a short story or a novella, a couple of paragraphs can be enough, but more substantial pieces, such as novels, may require even a few chapters of background information to give the necessary context. 

An example of a short exposition can be found in one of Sherlock Holmes' stories "The Red-Headed League." Arthur Conan Doyle describes the place and time of the action and introduces the heroes in five sentences before creating the enticing incident.

Depending on the placement of this literary tool in the text, researchers divide it into three main types: direct, delayed, and reverse exposition:

  • Direct exposition is the most common type and is placed at the very beginning of a work. This way, the writer maintains the chronological order of events: from things that occurred in the past to present adventures that are unfolding in front of the reader. This type can be found in "Romeo and Juliette," in a scene where, before meeting Juliette for the first time, Romeo tells Mercutio about his former love.
  • Delayed exposition allows the author to keep the reader intrigued longer and spice up their interest. In such a scenario, the writer begins the piece with the enticing incident, and only after a couple of chapters explains the reader the full context of what was happening previously. J.K. Rowling uses this type in the last Harry Potter book. This device can be found in the scene where the protagonist finds out about the nature of the Deathly Hallows from Xenophilius Lovegood.
  • Reverse exposition is located at the end of a literary work. Ordinarily, it is used in detective stories, where the author strives to keep the mystery alive until the final pages. An example can be found in "The Husband's Secret" by Liane Moriarty. In this piece, at the very end, the reader learns about a story that occurred many years before to the events of the book. And due to that revelation, the protagonist turns out to be a victim of circumstances instead of a murderer.