The late great Elmore Leonard advised authors to avoid prologues. His answer to prologues was to "drop in a backstory anywhere you want to." Ordinarily I'd follow his advice. After all, he had a good track record as storyteller. I handle prologues two ways: All three of my novels have them. I used brief prologues to introduce the background for my stories. I labored to make them concise and intriguing. The last thing an author wants to do is bore a reader at the beginning of a book. My latest novel has a prologue written by a retired Navy SEAL whose advice was invaluable during the writing of the book. I felt background from him would set the tone for the novel. I think his contribution helped set up the story and I elected to keep it. But back to Elmore Leonard's advice—Using dialog or a seamless backstory is probably the best way to eliminate the temptation to write windy prologues. My editor always encouraged me to use dialog rather than spending too many words explaining the "who, what, why and when" of a particular character or the setting. She's always right. The trick is making it seem natural as part of a conversation between two characters or perhaps a protagonist offering a brief history. Elmore Leonard would probably say, "Make it short or better yet, scrap it."