As with many of the topics we have already discussed, the decision of having a prologue or not is entirely up to you. Whether it is necessary for your story or not is sometimes another matter entirely. Let’s look at the definition of prologue before we continue.
Prologue (Noun): a separate introductory section of a literary or musical work.
There you have it. A prologue is an introduction to the story.
So, if your story begins in the middle of action or events set into motion by a previous incident (especially if it is years prior), you definitely should provide a prologue. The equivalent of this is running up and hugging someone without an introduction. You’ll either get shoved away or punched in the face, normally. In terms of your story, this is the reader putting the book down and moving along. They lose interest as soon as confusion sets in. To avoid that confusion altogether, you can have a brief introduction before the reader gets immersed into the story.
For a sequel. I believe all sequels should have a mandatory prologue in the beginning to recap the main events of the previous book. The reason for this is because I’m one of those people to go buy a bunch of books, get them home, and realize I have the second book in a series. Sure, I could spend time hunting down the first book while letting the second book collect dust. Or I can read the prologue provided, have a good idea of what’s happening, and thoroughly enjoy the book I selected regardless.
In these situations, just like in customer service, the reader is always right because they are who you want to read this product. You have to tailor it to their expectations, to a certain extent. Which brings up another topic we will discuss at a later date.
Personally when writing, I always include a prologue and an epilogue to my novels because it allows me to show how much time has passed between books, important events that occurred, and gives the reader clarity about what to expect and what is to come. I wouldn’t recommend prologues for shorter stories because it can appear to be a little silly.
Once again, the decision is entirely up to you. Whether you decide to prologue or not to prologue, get back to writing.