One of the sessions I went to at last weekend’s conference was on structuring a series. My main takeaway from that is that it’s important to find a good balance between a series being connected enough that people will want to read all the books and there being enough “on ramps” to allow new readers to jump into the series.
There are a lot of different ways to structure a series.
There’s the “one big book broken up into chunks” approach, like The Lord of the Rings or A Song of Ice and Fire, in which there’s an epic story published a bit at a time, and each volume doesn’t really have its own narrative arc. In this case, you’d better hope readers discover that first book because there’s no coming in to it late.
There’s probably the most common format, the “episodic” format, in which there may be some big-picture plot arcs and there are character arcs that stretch over the whole series, but each volume is still its own story with its own narrative arc and beginning, middle, and end. That’s what I’ve been doing with my series. There are shadings within that, with one extreme being a bit closer to the one big book style, like I’m doing with Rebels, where each book has its own narrative arc, but those arcs are part of a big picture arc and lead directly from one to the next. There’s no real jumping in to that series. You pretty much have to read the first book. In the middle would be the romantic mystery series, in which each book is its own distinct case, but the character stories arc through the whole series, usually with a romantic relationship gradually developing between two of the characters. You could pick up any book to read first, but you’ll probably get more out of the character stories if you read them in order. The extreme of “episodic” would probably be the mystery series without real character arcs, where each book is entirely separate and the world more or less resets between books, like the Nancy Drew series. Nothing changes in that world, and you can read the books in any order without it making any difference in the narrative.
Then there’s the “spinoff” format, in which each book in the series is about a different character. The best friend of the main character in book one becomes the main character in book 2, etc. You see a lot of this in romance, where it can be difficult to follow the same characters into more books since each book needs a romantic happy ending. So you’ll get a series about a group of friends, with book one establishing the group and the supporting characters from one book becoming the main characters in later books, with the previous main characters becoming supporting characters so you can see how their lives are going. Each main plot is generally distinct, so you can jump in anywhere, but it will probably make more sense and be more meaningful if you read them in order.
And there’s the “world” format, in which the series is mostly about a particular place, with each book being about a different aspect of that place or different people in that place, with some crossover (characters from one story showing up in another story). The big example would be Terry Pratchett’s Discworld series. There are sub-series within the big series that work best if read in order, but you can generally pick a thread and dive in almost anywhere. The more books of the series you’re read, the richer the world feels, and it rewards re-reading after you’ve read more so that you recognize all the people who show up and understand how their stories fit into the big picture.
I’ve been thinking of different kinds of series I might try writing as a way to build an audience. I’ve thought about doing that mystery format, maybe a “strange small town” situation with a case in each book and the amateur sleuth and the pro detective at first clashing and then gradually falling for each other over the course of the series, though I think I would do it more as contemporary fantasy than as mystery, with a variety of cases rather than just murders (does it have to be murder to be a mystery?). I have a hard time suspending disbelief when a small town has a ridiculously high per capita murder rate, and there are a lot of other kinds of cases to solve.
I’ve also thought about trying a “world” series, where I build a fantasy realm and tell a variety of overlapping stories in that realm. That would take some planning to figure out how it all connects, and I’d have to find a way to make it a truly interesting place. I think this is what I might do with that idea of the low-stress escapist fantasy concept and make it be a world people want to visit and enjoy, with the characters having adventures but not necessarily mortal peril.
But first I have to finish revising the book I’m working on, then finish writing a book, then write another book.