How to write a book trilogy: 5 crucial steps

Want to learn how tow write a triad of books that keeps readers with you to the end? Here are 5 key steps for how to write a book trilogy:

How to write a trilogy series:

1. Study trilogies' structure and learn what works
2. Plan a thread that builds through all three books
3. Treat the middle book as a bridge to the finale
4. Leave real conclusion for the third book
5. Choose three titles that resonate together strongly

Let's examine each step closer:

1: Study trilogies' structure and learn what works

The number three crops up everywhere in storytelling: Three wise men; three little pigs; three blind mice; the Father, the Son and the Holy Ghost. The 'Rule of Three' as this structural device is known serves multiple purposes. As Joe Bunting reminds, remembering the course of events is crucial to reading a story, and repetition in threes helps stories to stick in our minds. Bunting says:

'The first two times build tension and the third releases the tension, either through resolution or a twist.'

Now examine some of the great trilogies and think about how they are structured. Take J.R.R. Tolkien's Lord of the Rings trilogy, for example.

The first book, The Fellowship of the Ring, establishes the central cast of the book, introducing the reader to the unlikely hero Frodo and his genial sidekick Samwise Gamgee, along with the wizard Gandalf and the primary villain of the story, Sauron. The book builds tension, as Frodo undertakes to destroy the dangerous ring of the title.

The fellowship encounters multiple challenges and the party decreases in size even as the perils of their quest grow more threatening. When writing the first book of your own trilogy, be it a fantasy novel or a thriller or other genre, think about how:

• Characters' emotional load can increase to create tension (Frodo has to cope with the disappearance of pivotal members of his party)
• Characters' obstacles can become more challenging (Frodo is more vulnerable at the end than at the start, having only one person to accompany him into dangerous territory)
• The action of the story can move to a new location or territory that holds unknown surprises

In the second novel of Tolkien's trilogy, The Two Towers, additional characters are introduced. Tolkien's multiple conflicts create more questions for the reader.

A branching out of stories as Frodo's party is scattered creates mounting tension: the action occurs across several locations simultaneously, rather than only on the hero's path. This complication creates intrigue in the reader, who has not just one outcome (the ultimate goal of the quest) to wonder about but several.

The final novel of Tolkien's trilogy, The Return of the King does exactly what the third book in a trilogy should do. It:

• Resolves major plot lines and tensions, bringing the novel as well as the wider story arc to a satisfying conclusion
• wraps up without being too predictable (Frodo returns to find his home village greatly altered)
• Adds suspense before the final resolution: The protagonist's abduction creates further uncertainty and suspense so that there are minor arcs of increasing tension and resolution within the wider resolution itself.

Examine other favourite trilogies. Read over plot summaries if you need to refresh your memory. Think about what is effective about the overarching trajectory from book to book. Ask:

• How does each book end: What makes the reader desperately need another installment?
• What is the main story arc?
• How does the author use smaller story arcs within each novel to sustain interest over the trilogy? Tolkien, for example, changes the story between books one and two from a linear, group quest to multiple stories and predicaments. This creates increased interest because there are suddenly multiple tensions requiring resolution.

2: Plan a thread that builds through all three books

One of the most important tips for how to write a trilogy is to make sure each book is a point along a series-spanning continuum. If your books read as entirely unrelated stories, there's not anything to make them a real trilogy.

In Tolkien's much-loved trilogy, the quest to Mount Doom is the overarching thread that draws the three books together, making the first two build to a final, conflict-saturated climax.

Epic quest narratives aren't the only great trilogy fodder. Leo Tolstoy's semi-autobiographical trilogy consisting of the books Childhood, Boyhood, and Youth, takes the successive stages of growing up and becoming aware of one's place in the world as a running theme.

There are many different threads that can run through your three novels, for example:

• Multiple points along a quest to a climax in book three (as in Tolkien's trilogy)
• Successive stages of a central character's life (as in Tolstoy's trilogy)

Whatever unifying element you choose, intrigue the reader so that they commit early to getting to the end of book three. One way to create this investment is to make the middle book a rickety bridge to the third:

3: Treat the middle book as a bridge to the finale

YA Author Elana Johnson reminds us that writing the second book in a trilogy isn't easy:

'The author has the challenge of living up to Book One, and the characters aren't new. The world isn't new. The problems aren't new.'

Think about how you can make your world and characters new in your second book, however:

• The book shifts to a new location
• New characters join the cast (or old characters depart or even die)
• Things you made the reader believe were true in the first book become less certain (for example, the reader might think a character corrupt, or else dead, but will discover they are not)

Besides making your middle book offer the reader some element of surprise, think of how you can increase tension and uncertainty. Make the second book like a rickety bridge to the third. Tolkien does this in The Lord of the Rings by:

• Multiplying the settings of the book and making each offer a subset of characters their own challenges
• Having characters make surprise returns
• Introducing new (and not entirely trustworthy) characters who will be pivotal to the remainder of the story

Draw on elements of surprise and uncertainty because they make readers curious to find out what happens next.

4: Leave real conclusion for the third book

Having built up suspense and intrigue over three novels, it's important to create a satisfying ending that lives up to the build-up. At the same time, the ending shouldn't be so predictable and obvious that readers are left thinking 'I could have just read the first half of the book'. You can learn how to write a book trilogy ending from the greats:

Tolkien makes the ending of his trilogy surprising by adding dramatic events in Frodo's hometown that come after the climax of the main story line. If the trilogy had simply ended with the party achieving their objective, there wouldn't be this extra element of surprise. At the same time, Tolkien does deliver on the climax the trilogy promises the reader from the outset.

Things to avoid in writing the final book in your trilogy:

• Too much backstory: Don't assume the reader has forgotten absolutely everything from the previous two books
• The deus ex machina - a plot development that comes in the nick of time to deliver the main character (and the author) from a complex situation
• Fizzling out - In Tolkien's trilogy, the hero Frodo doesn't simply return home to find everything rosy: conflict has spread even to his own hometown

A strong climax resolves the loose ends of the story without being too obvious or predictable.

5: Choose three titles that resonate together strongly

You should leave off choosing titles for your trilogy until the end of completing all three manuscripts, if possible. This is because you'll have more to draw on and will be able to see links between novels clearer. Publishing doesn't always work this way, of course. Often authors may publish a single work, not expecting it to turn into a trilogy.

To write titles that link your series together, you could:

• Use titles that link together the chronology of the series (for example Tolstoy's Childhood, Boyhood, and Youth)
• Try titles that hint at pivotal plot developments in each novel
• Create titles that contain variations on an important character's name (for example, in Mervyn Peake's Gothic fantasy trilogy Gormenghast, the first in the series Titus Groan is named after the eponymous main character while the third (Titus Alone) refers to his solitary travels away from his castle.

In each of the trilogies mentioned above, the title is vague enough not to give away too much. Each title also gives the reader an idea of what the themes in the stories are. In the case of Tolstoy's trilogy, the reader even has a sense of the chronology that will emerge over the series.

If you want to learn how to write a book trilogy, focus on the five steps outlined above. To begin, understand what works in classic trilogies. Then form an idea of the major narrative threads that will run throughout your trilogy. Work out how you're going to make the middle book propel the action towards the climax of the third. Find a satisfying conclusion for the third book and tie it all together with memorable titles that suggest how the books relate to one another.

Ready to write a trilogy? Start honing your central story idea and get helpful writing feedback.