Agent Carly Watters from PS Literary has written a “How to” writing book. Here is an excerpt:
The Dreaded Prologue
Can reader coming to your work for the first time get past your prologue?
Fact: Prologues in fiction should be avoided.
This may be unpopular advice but there are reason why agents and editors alike refrain from keeping prologues once they begin working on material.
Prologues are often back story and backstory can be added anywhere.
They can be distracting when the reader doesn’t know the characters yet and so the reader may skip it entirely.
Prologues often show that the writer doesn’t know where to start the story.
If the material in the prologue is important, why isn’t it in the body of the work?
The prologue may turn readers off from the novel before it even gets moving, so why put yourself at a disadvantage?
You might wave your most-loved book or WIP at me and say, it worked for so-and-so therefore it can work for me too! Alas, this is very rare. It’s a subtle strategy that needs to be reworked countless times, not a writing tool that can be tacked on for clarity. Are you the exception?
Tip: Use an epigraph instead. If you are trying to set up themes or a frame of mind when readers enter the novel an epigraph is a great succinct way of getting this information across.