I've just finished writing the prologue to my first novel (yes my first) and it comes out at around nine pages long. Now I know that this will more than likely have to be significantly cut down in its final form, so my question is, Ideally, how long should the average prologue be?
Can open. Worms everywhere. If you aren't aware, prologues are rather controversial in publishing. For many readers, agents, and editors, the ideal prologue length is 0 words. See a recent thread for differing viewpoints: https://www.writingforums.org/threads/to-prologue-or-not-to-prologue-that-is-the-question.153926/ If you go ahead with a prologue, I don't think there's an ideal length or any kind of average, any more than there's an average chapter length. I did some research into chapter length recently and couldn't find any stats on chapter lengths, which just shows you how unimportant it is. Some books don't even have chapters, just scenes. I would caution against having lots of very short chapters (under 1,500 words or so) in an adult novel, but for a one-off or for a prologue? I'd say make it as long as it needs to be. As another aside, it's good to get into the habit of using word count instead of numbers of pages. Nine pages of dialogue-heavy writing in size 14 font will be significantly shorter than nine pages of narrative-heavy writing in size 10 font. It's hard to talk about length when you don't know how long something actually is. Word count removes the ambiguity. I'll shh with my unsolicited advice now.
Most writers count length in words not pages. The reason being, depending on your font/word size the number of pages will vary. Most word processors tell you your word count (in Microsoft Word it's down in the bottom left corner), but if yours doesn't you can paste it here and it will tell you. As for the actual question, there's no set length, but you definitely don't want it to be too long. If a prologue drags on, you're likely to lose readers.
A Prologue is a particular type of chapter, and can be any length you want. If it's entertaining and gripping or intriguing—same as the rest of your book—your readers aren't going to care how long it is. Study the technique of writing a good prologue, and learn how prologues can help to form your storytelling structure. Prologues are not always necessary of course, but writers shouldn't avoid them out of fear that somebody out there won't like them on sight. They are a storytelling tool you can use, or choose not to use. Just learn what they can do for you.
I kind of think prologues are a cheap trick. It's not that they noticeably will damage anything, but it's better if you can work in whatever you want to say in the story.
