Sue Grimshaw (who is lovely, and approachable, and a breath of fresh air) really threw the cat amongst the proverbial chickens when she advised us during a cold read at the Romance Writers of New Zealand conference, that she like prologues.
An editor who likes prologues?
Yes, apparently Sue was serious and, to tell you the truth, I couldn't be happier because if there's something I love, as a reader, it's a well thought out prologue. One that makes me think I've been let-in on a seriously cool secret right from the beginning.
Of course, that doesn't mean I think we need a lot of prologues at the beginning of books and I don't think that's what Sue was saying.
My rule of thumb? Nut out the pertinent information, drill it right down to the most important facts, then write a prologue that creates the feel and tone you want for your manuscript.
If you're having problems with it. If it doesn't flow or come out right,
admit that maybe you don't need a prologue - as all it is, is a lump of backstory - which may be interesting but not the best way to hook your readers (or an editor).