Types of Series

Jo Walton divides series up into 4 types:

1. A single novel that happens to be published in multiple volumes, e.g. Lord of the Rings
2. The volumes have individual arcs, but there is also an overarching story which relies on the books being read in order without gaps. This is what I most often think of when I hear the word series.
3. The volumes are largely independant—and can be read out of order—but have common threads, e.g. the Vorkosigan Saga. I like the term “saga” to refer to these.
4. The volumes are entirely independant, sharing only setting and theme elements, e.g. Guy Gavriel Kay’s historical-ish fiction. I often find this kind of series called “world” or “universe”.

It’s worth noting that series of a looser type may contain subsets that form a stricter type of series. For example Bujold’s type 4 World of the Five Gods contains both the Penric books, which are a type 2 series, and the Chalion books, which are a (small) type 3 saga.

I’ve found myself using this classification a bunch, and figured it was easier to reproduce the essentials here than to keep linking to a blog post with the idea buried in the middle of it.