The Solution to Stand-Alone vs. Trilogy: The Star Wars Option
I write fantasy. Some adult, some young adult. Fantasy, particularly YA, seems to be written as series almost by default. The stand-alone novel has become rare enough in this genre that reviews of such books often start with something along the lines of, "It is so refreshing to read a fantasy book in which the story actually concludes at the end of the book."
My first (publishable) fantasy novel was titled Bloodloss Empire. When I conceived of it, there was no intentional thought put into whether it should be stand-alone or a series - I had a premise from which I could create an original world and a surreal mystery and I knew that the reader would be disappointed if the mystery was not resolved by the end of the book. It didn't seem to me it could be anything other than a stand-alone.
But as I wrote, random sequel ideas floated through my head. Just because the mystery of this book is solved, doesn't mean new mysteries (that tie into this book's premise) can't pop up later in these characters' lives. Just because the main bad guy dies at the end of this book doesn't mean some of the less central antagonists won't come back stronger and more determined in the future.
And as I took notes and started shaping the idea for two sequel books, it occurred to me that what I was creating was a trilogy structure much like the original Star Wars, which I started to think of as an Optional Trilogy.
I first saw Star Wars when I was five years-old. At the end of the film Luke blew up the Death Star, so the good guys won, right? I had no concept of this thing called a sequel, and learning of the existence of The Empire Strikes Back was a surprise to me. But, while Star Wars has a satisfying ending, you can hardly say the same thing about The Empire Strikes Back, can you? There's not a person on Earth who can finish that film and say, "Okay, the rebels are scattered, the Empire still rules with an iron fist, and Han Solo's a frozen prisoner of Jabba. I don't need to know what happens next."
I like this structure. You want to just watch the first one? Great, story's over. You want to dive into the second one? Okay, but if you watch the second one you've got to watch the third. These days all the fantasy trilogies, especially in YA, end the first book on an upbeat (Katniss survived the Hunger Games) but don't have a satisfying conclusion that gives you the option of not continuing the series (this horrible government still has its boot on the neck of the citizens).
Though I can't promise I'll do this every time, I'm going to strive to write any trilogies I create as Optional Trilogies. I not only like giving the readers that option, but it gives me one as well - if the first book is well received and readers seem to want sequels, I can write them, if not, we can both move on to the next thing. I've always got a next thing I'm excited to write.