Definition of prologue:
Pro: Before. (Greek) Logos: Word. Before the word.
1 : the preface or introduction to a literary work
2a : a speech often in verse addressed to the audience by an actor at the beginning of a play
b : the actor speaking such a prologue
3 : an introductory or preceding event or development
Does your novel even need a prologue?
Research indicates agents don’t like prologues and neither do readers; in fact, readers are reporting that they skip prologues because they don’t want the words before the words (and thought of that way, it does seem a little unnecessary, right? Why write a whole book if it can’t start at the beginning?). I have no empirical data what buying editors with publishing houses like.
Note that I said readers skip prologues. Reason #1 not to write a prologue. You’ve shot your book in the foot if you annoy a reader from the first page. Agents know this, too.
I am one of those who skip prologues. I don’t read them until after I’ve finished the book, just to see if I missed anything. It is a rare one that makes me say, “Oh, I wish I’d read that so I’d known what was going on before the story began.” Chances are good I never finished the book that relied so heavily on the prologue.
My reasons for not liking them? They are generally too long and borrrrring. They tell too much (i.e., infodump) and I’ve no reason to be involved yet, or care a whit. They could be in 3rd person POV, a sneaky way to allow the author to stick info he couldn’t otherwise get in the story because chapter one begins the real story in 1st person POV. Or perhaps the characters or subject are too far removed from the jacket copy to make a connection to what I expected to read.
Prologues are sometimes used as “future shots”: The book is back story up to the point where the prologue slides in (there’s a clear gap, and one has to remember that that was Prologue Scene Goes Here spot, and then the readers have a rollercoaster ride to the finish. You’ve seen the movie or TV show that opens: “Three hours previously. . . .” You just didn’t know you were watching a prologue in action.
Writing a prologue for your sci-fi or fantasy novel
Some sci-fi and many fantasy novels are good genres for prologues, but be careful with overload. Fantasy novels especially, given the involved back story and family genealogy can be grossly overused. Those prologues can set the scene, time, and coming storm, and get the reader mentally ready for the (maybe/sometimes) 1000-year leap that happens in chapter one. The best are still short and concise. Five hundred to a thousand words. Those, I read.
Prologue or chapter 1?
When I’m editing manuscripts, I often suggest the prologue would better fit as chapter one, or deleted altogether and the information spread out and shown in other places throughout the story. This is one of the better reasons to hire a professional editor (yes, blatant self-promotion there) because we’ve seen hundreds if not thousands of prologues and can tell you if you need it or not.
In fact, other than in a few sci-fi and fantasy novels, the only prologue I remember not campaigning for removal was this one: “I was going to be late for work one Tuesday morning because I couldn’t get the doggone car started. In hindsight, maybe I shouldn’t have called the car guy to help me: I died when I got on the Interstate fifty-five minutes later.” This author did not make the mistake of going into back story in chapter one. He just leapt into chapter one like a tiger. It was great.
That prologue was rare. Lead-ins—putting the hook in before chapter one in an attempt to make chapter one not so critically important—too often backfire. Avoid them, is my advice.