The prologue gives background information to the story that would give the reader insight that helps the story move along that is not found within the story itself. An author might add a prologue to help the story flow more smoothly by getting in information that would be clumsily delivered otherwise.
The epilogue is the opposite. It helps tie up loose ends or possibly hint about a sequel or continuation of the series. An author could add an epilogue to entice the reader into buying the next book in a series or provide resolution by telling us how the characters end up further down the timeline.
There are multiple ways to use prologue and epilogue.
1. In Thrillers, the story can begin with a scene from the antagonist's point of view. This is good if you are following a serial killer, not so good if you are listening to an angry spouse rant. It shouldn’t attempt to tell the reader every little detail about your story world or the history of a situation before the action begins. Some readers will flip past the prologue anyway, especially if it is long. If it is used to set up the villain as really, really bad, it could be a turn off. Your villain is supposed to be bad. The first chapter should include the inciting event. If your prologue does that job with the antagonist or secondary characters, it is weaker than meeting the protagonist and making the reader care about how the inciting event affects the hero.
2. In Literary stories, we often first hear from the protagonist long after the events are over. The entire story is one long memoir with an epilogue that reinforces the wisdom gained. The entire story can be told in flashback between the prologue and epilogue “bookends.” It irritates, rather than delights, if not done well. Many readers don't mind this method if it is intriguing or poignant.
3. In a Fantasy, the prologue sometimes sets up the time, place, and story world. If it is kept short, the reader might actually read it. Otherwise, they flip to chapter one. If necessary, they reference the prologue later. You should be able to fit in the crucial setup and history without using this device. Done badly, it is received as melodrama. Too long and the reader feels overburdened before the story begins, and they may not purchase the book at all.
4. In a Suspense story, the prologue can set up the story problem in advance or hint at the ending before the beginning to set up suspense. You should be able to write suspense without this device, but it is certainly used.
5. In a Mystery, the author often writes the prologue from the villain’s POV or sets up the finding of the body by secondary or tertiary characters. This can be a weak start and the reader might flip past it. If the mystery has multiple scenes from the killer’s POV, then the prologue should really be chapter one or two. If this is the only scene from his POV, you have to ask if it is really needed and if it is a way of introducing false suspense. It is much stronger to pull the reader in with the sleuth being made aware of the crime.
6. A prologue may introduce a past mystery relating to a present day story. If the book alternates past story and present story scenes, the prologue could easily be converted to chapter one. Since a reader picks up the book and opens it to read the first few pages, you might lose them with the past story if the setting or situation bores them. These prologues tend to add color and set the stage with no real action or interaction for the reader to care about. If you use it, make it count. Consider starting with the contemporary story in chapter one, then weaving in the past story as chapter two. Give the reader a reason to care.
1. Do you really need a prologue or are you just in love with it?
2. Is it crafted with intention or lazy writing?
3. Is it riveting in its own right?
4. Is it too long?
5. Does it regurgitate information or try to stuff an entire world history in before the story starts? If so, cut it.
6. Does the story work without it? If not, are you in trouble if the editor says “Delete?”
For more information on prologue and epilogue, check out:
Backstory, How Much Do You Use?
Diana Hurwitz is the author of Story Building Blocks: The Four Layers of Conflict, Story Building Blocks II: Crafting Believable Conflict, Story Building Blocks III: The Revision Layers, and the YA adventure series Mythikas Island. Her weekly blog, Game On: Crafting Believable Conflict explores how characters behave and misbehave. Visit DianaHurwitz.com for more information and free writing tools. You can follow her on Facebook and Twitter.