Why are trilogies so prevalent in Fantasy? (I don't really recall trilogies outside genre-literature and even in genre, trilogies in sci-fi seem to be less prevalent).

Can it be simply chalked down to Tolkien's influence? Or, is this because fantasy is set in some kind of mythical period of history and certain story patterns(like the hero's tales) fit themselves to trilogies very well?

Tried to do some digging up on the prevalence of trilogies, to convince people that it's true.

  • The wiki page on trilogies says "Trilogies — and series in general — are common in science fiction and fantasy because ..."
  • Doing searches for "trilogies in [genre]" or "[genre] trilogies" yields much more higher results for fantasy than science fiction, thriller, literature and mystery.
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    Depending on how you define 'genre-literature' there are plenty of trilogies outside of science-fiction and fantasy.
    – HorusKol
    Jul 25, 2011 at 23:32
  • Three is generally an important number - in storytelling, in painting, in pattern id, in Christianity, etc. It predates Tolkien by quite a bit. I realize that you probably already know that, but the question doesn't make it entirely clear for me whether you view this trend as being a separate thing when talking about fantasy.
    – Misha R
    Jan 5, 2018 at 19:47
  • And Miss Prism wrote a three-volume novel, in which the good end happily and the bad unhappily, for that is what fiction means.
    – TRiG
    Feb 26, 2018 at 12:45
  • 3
    The question seems to be based on a couple of misconceptions: that fantasy = Tolkien & his imitators, and that The Lord of the Rings is a trilogy.
    – user14111
    Mar 8, 2022 at 10:51

5 Answers 5


Here are three reasons:

  1. Fantasy stories need to go into details that real-world-based fiction doesn't: cultures, politics, religions, biology, magic, science, technology, you name it. And part of the fun of it is exploring a completely fantastic setting where all the rules are different; when you take out that exploration, I think you'd get something much closer to magical realism.
  2. As jwenting points out, epics go well in a trilogy format. It's a rare writer and story that can get away with more. And if an author can get people to buy into book two, why not write three?
  3. Fantasy readers, I think, are much more likely to be reading for the fun of it than the general public, and are much more likely to be tolerant and accepting of a story that doesn't finish in one book. Meanwhile, if your main goal in reading a book is to pass five hours on an airplane, you aren't going to pick up a three-volume doorstopper.
  • 10
    I found this to be interesting. A question about trilogies, answered in 3 parts with 3 upvotes. Jul 26, 2011 at 13:24
  • 1
    @Oghma: I hope that doesn't stop people from upvoting. ;-)
    – jprete
    Jul 27, 2011 at 17:14
  • I like the third point myself. I feel like those who read fantasy are seeking full immersion into another world and the more descriptive and alive it seems, the better. Jan 17, 2018 at 19:25

Well firstly, most fantasy genre works are single books, not trilogies or otherwise. That being said, assuming a book is popular enough to be made into a sequel, it's usually spanned into three books because most publishing companies will try to maximize profits in this way.

Consider also the rule of three. Three is typically considered a "well-rounded" number for what concerns stories because it represents a beginning, middle, and end.

  • 7
    It also mimics the play in three acts which is older than dirt.
    – Jeff
    Jul 25, 2011 at 14:25
  • Not to mention that when something is shown to work in business other businesses tend to quickly adopt the model. You can almost map the Star Wars trilogy to the lord of the rings if you do it with generalizations.
    – Chad
    Jul 26, 2011 at 15:46
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    @Neil:Can you provide support for your claim that most fantasy genre books are standalones?
    – apoorv020
    Jul 29, 2011 at 16:57

Many epics take more space than a publisher is willing to publish in a single volume. As customers have gotten used to the trilogy format, that thus becomes a good target to aim for when writing something that won't fit in say 300-450 pages. Make it a 2 volume series, and people will wonder when part 3 will be published, Make it a 4 part series and you get complaints after part 3 that it's "unfinished".
Tolkien has nothing to do with that, trilogies have existed long before he wrote his masterpiece (which was originally released as a series of 7 books btw, not a trilogy, only later were those 7 volumes combined with appendices released as a 3 volume set).

  • 5
    :Actually it was six books, and even then they were published as three volumes I believe.
    – apoorv020
    Jul 25, 2011 at 12:11
  • 4
    @apoorv020: Tolkien never wanted to split it into a trilogy, but the publishing company obliged him because they didn't think it would sell otherwise, having as many pages as it did.
    – Neil
    Jul 25, 2011 at 12:53
  • 3
    @apoorv020: Yeah, he originally intended it to be a single book, but it would have been quite long.
    – Neil
    Jul 25, 2011 at 14:33
  • 2
    @apoorv020: It says so in the foreword to the Lord of the Rings that he intended it to be one volume. Jul 26, 2011 at 0:17
  • 2
    @gunbuster363: Actually, I own TLotR all in one paperback volume. This is currently the first hit for "Lord of the Rings" in books at amazon.com. And I'm sure Stephenson's Anathem is a bigger and heavier book.
    – sbi
    Aug 4, 2011 at 9:14

Note: We had a very similar question on Writers.SE; I'm cross-posting my answer from there, adjusted to your specific question.

I think the reason for the popularity of the trilogy structure in the fantasy genre is simply that fantasy novels tend to be long. This occurs for for many reasons, including:

  • Fantasy novels typically require lots of world-building exposition, explaining the setting, the mechanics of magic, central factions in the world, etc. etc.
  • Fantasy novels are often interested in exploration; showing off various fantastical elements (places, creatures, magic items...) is often a lot of the book's focus. So the narrative is designed with a lot of shifting from place to place, and introducing new elements very frequently.
  • Fantasy novels often have epic plots, about the rise and fall of kingdoms and dragons and deities. Epic plots tend naturally to be of greater length, because this gives both time and wordcount to properly build up this epic scope. Readers will probably not care much whether the Empire of Lime can defeat the Bespectacled Dragon unless they've gotten a sense of all these elements as being rich, intriguing, and with real substance.

Since fantasy tends to expand into great length, multi-book structures are necessary. The moment that's a given, trilogies are a natural choice -

  • it's a short, well-defined series;
  • that's a length fantasy readers will be willing to risk dipping into;
  • the three-book structure can, in many senses, duplicate the three-act structure;
  • it's a short as you can get besides a duo (which - maybe this is just me - feels like an awkward length, which needs to work harder to justify the split into multiple books, and is harder to structure a single narrative around).

In other words, trilogies are popular because they're "short" (compared to longer sagas), not because they're long (compared to stand-alones). I think you'll find that stand-alones are actually easier sells, both to publishers and to readers - they'd much rather buy/read something complete, self-contained, and non-risky. It's simply that such books are less common, particularly when a lot of genre fans are interested in fantasy specifically for the length-inducing elements I've mentioned (world-building, exploration, epic plots).


Most modern storytelling follow a Three act structure. Epics and series often have micro plots (plots that develop and resolve internal to the "episode"), and macro plots that span the entire story (also known as major and minor story arcs). As a story expands, the structure stays fairly constant, and can become a fractal of the three act design. So therefor, the entire story fits into three acts, or three books/movies/whatever, and each piece is itself a three act process.

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