What does 1.5 mean in a book series? Novellas, prequels and reading order
You finish book one of a series, go looking for book two, and find a "Book 1.5" in between. It is not a typo and you have not missed half a book. The decimal numbers are a convention for the shorter works that sit between the main books, and once you know how they work, the reading order of almost any series makes sense.
What the numbers mean
- 1, 2, 3… The main books, the ones the series is built on.
- 0.5 A prequel: a shorter story set before book one, often written later.
- 1.5, 2.5… A novella or short story that sits between two main books: 1.5 goes between book one and book two.
- 1.1, 1.2, 1.3… Several short works between the same two books, in their order. Some sites number them 1.3, 1.5 and 1.7 instead; the idea is the same.
- A spin-off is set in the same world with different main characters. Some series number it like a novella, others start a new series for it.
- A companion novel shares the world but stands alone. It often has no number at all.
Who decides the number
Usually not the author. Most decimal numbers come from book catalogues and the volunteers who keep them: a novella published between book one and book two is listed as 1.5, whatever the cover says. That is why the same novella can be 1.5 on one site and 2.5 on another, if one numbers by story order and the other by publication. When the author publishes a reading order on their website, that order wins.
Do you have to read the .5 books?
Most of the time, no. Novellas are often written for readers who already love the series: a side character's story, a wedding, a scene from the other point of view. Many first appear as newsletter extras or in anthologies. But not always. Some introduce a character who matters later, or cover a jump in time that the next main book assumes you know. A quick test: if the next main book opens with consequences you do not recognise, the novella was not optional. When in doubt, read the main books first and come back to the novellas between rereads.
Publication order or story order?
For a first read, publication order is the safe choice. It is the order in which the author chose to reveal things, and a prequel written after book three often assumes you know how book three ends. Story order, also called chronological order, is a pleasure on a reread, when nothing can be spoiled. A few authors recommend a specific mixed order; if they do, follow it.
Box sets and omnibus editions
A box set, a trilogy edition or an omnibus puts several books in one volume, sometimes with a bonus novella. It is easier to keep track if each book inside counts as its own book: you will want to rate them separately, and the numbers stay right.
Keeping your series in order in Storyfeel
In Storyfeel, Series keeps each series with its books in reading order and shows what comes next. Tap Add series and add the books. To change the order, drag a cover: drop it between two covers and Storyfeel asks whether it is a Novella or a prequel, and numbers it for you, 3.5 between the third and fourth books and 0.5 before the first. Several between the same two books go up in tenths, 1.1, 1.2, 1.3, in their order. A Spin-off stays in the reading order too, numbered like a novella, with its label on the cover.
When you add a box set, Storyfeel opens it into its series and books instead of saving one card. More by this author looks up the author's other books and tells you which you already have; the ones not out yet go to your list of releases. And Next in my series, on My Journey, shows the next book of every series you are reading.
To hear when the next book in a series comes out, read how to get notified when an author releases a new book. Bringing your series from Goodreads? Export your Goodreads library first. Or start your reading journal free.