I'm reading the Song of Ice and Fire series at the moment, largely because a boxed set of it was going cheap in the sales. It has me thinking a bit about written series and where they fit into the world these days. What do they do for the author, for the publisher, and for the reader? How do we go about writing them sensibly? I've worked on a number of series for other people, and my novel Witch Hunt is at least a sequel to Searching, so in theory, I should understand this stuff by now, right?
The basic idea floating around seems to be that publishers don't like committing to series. Presumably, they don't want to commit themselves to tying up resources in books they don't know the quality of in advance. Yet there are plenty of series out there, so it can't apply everywhere.
For the author and the reader, a series gives almost the same thing: a chance to play in the same world again. Everyone knows what the rules are and how things work. Everyone knows the biggest characters (and the author knows which characters the readers like best by now). Yet not all series are the same. There are a few different types. These include:
(For best comic effect, read all of these as 'Harry Potter and...'. Or don't).
The single epic story. Take the Lord of the Rings. No really, take it away. It has too many songs. Before that though, notice that it's all one story, and that the second one in particular doesn't come to that satisfying an ending in itself. It really does feel like one story that is too big for one book. The same is true for the Song of Ice and Fire series mentioned above. If you have a story that is going on and on, and occasionally you think 'I've got five hundred pages here, I'd better stop and call it a book' then this is the one you're doing.
The consecutive sequels. A lot of urban fantasy series seem to have started off like this, and possibly the same could be said of Pratchett's early work. They submitted a single book, the publishers went 'oh, all right then' and it turned out to be popular enough for them to write a sequel, and another, and... Here the thing is that they're separate, distinct books, probably with a shared world and so forth because otherwise they wouldn't be a series, but each one imagined separately. They don't set one another up as such even if one inevitably builds on the last.
The overarching plot. This is an idea common in TV series, where there's a series plot arc, but there has to be a solid arc for each episode. It's common in a lot of modern book series, and is a lot better as a tactic than just assuming that your readers will read the next one for the rest of the plot. Its main advantage is that it manages to combine definite story endings for each book, giving a sense of satisfaction, with unresolved elements, giving a sense of interest for the next one. Its big disadvantage is that it has to keep getting bigger and bigger, moving away from where you started.
The hastily acquired plot. A variation on the above, coming in largely when a lot of the urban fantasy writers I referred to in the first one realised they had multi-book deals and really should acquire some kind of overarching plot. It's about sitting down, looking at all the things that have happened previously, and trying to work out how you can possibly tie them together so it looks like you meant it all along. I should point out that there's nothing actually wrong with this. It's just hard to do convincingly.
The recurring theme. In this sort of series, you have a series of essentially separate stories, all of which have a recurring setting or theme to bind them together. It's quite common in romance series, for example, where you can't really have one person falling absolutely in love five or six times without it seeming a bit odd, but you can have five or six people in the same job (or the same pantheon of supernatural beings, if paranormal is what you do) who have that happen to them.
The shifting baton. This is just a variation on the recurring theme, where an author emphasises a secondary character in one book, to create enough interest in them that people buy the book where they're a main character. Or to put it less cynically, they try out the character in the background to see if they will work in the foreground.