How to Write a Trilogy: The Definitive Guide

Doug Landsborough
April 20, 2023

The best things come in pairs… er, threes, actually. Like dessert. Who would say no to three desserts? There are surely one (or three) million other things, but that’s not why we’re here.

We’re here to talk about one specific group of three things: a trilogy. Specifically, how to write one.

A trilogy is a series of three books completing a more extensive, overarching narrative. Each of the three stories is a complete tale unto itself—meaning each has a beginning, middle, end, conflicts, character arcs, and themes

The story told by the entire trilogy has all of those elements, too, just on a much grander scale.

Trilogies have a bunch of benefits. They allow you to dive deeper into characters, backstories, and plotlines than a single book can. They let you explore multiple aspects of your world. For those looking to earn a living from writing, they also go a lot further for your marketing spend.

Sure, there are times when a story shouldn’t be a trilogy. As we go through this article, you’ll get a feel for whether you want one book or three. On the other hand, you might learn that you want more than three books.

So brace yourself. In this article, we’ll cover:

  • Everything you need to brainstorm your trilogy
  • Concrete tips for writing all three books in a trilogy

Unlike your favorite trilogies, you won’t have to wait months or years for what’s next. You just need to scroll down to get started.

Brainstorming Your Trilogy

Before you can start writing your three stories, you must figure out what tale you want to tell. Like I said, not every story warrants a trilogy. So first, let’s come up with something worthy of such an epic series.

Choosing the genre

Your starting point is determining the genre you want to write. While there are no rules etched into stone tablets about what genre trilogies can be, some categories are better suited for this type of series.

This isn’t an exhaustive list, but you should be able to figure out what you want to write or whether your genre fits based on the descriptions of these categories.

Genres that work well with trilogies:

  • Fantasy and sci-fi tend to have stories of bigger stakes and scale, resulting in absurdly long novels or multi-book series. This might not apply to all subgenres of these categories, like urban fantasy, which can span a seemingly unending number of serialized books. Still, in general, these genres work well with trilogies.
  • Thrillers are great for trilogies because they can have a bigger plot divided into three exciting books. Each of these stories can contribute to a more extensive understanding of the super secret plot to take over the world while simultaneously upping the ante throughout the series.
  • Historical fiction stories can work well in a trilogy, especially when covering significant historical events. This could include events like World War II, revolutions, or even the life of important people, inventors, etc.

Genres that don’t work as well with trilogies (but still can!):

  • Romance books must have a happily ever after or a happy for now ending. These add a certain finality to books that don’t jive well with trilogies. That said, romance trilogies exist, especially in subgenres like fantasy romance. So don’t jump down my throat, romance authors.
  • Literary fiction is a big category that tackles real-life events and topics. Unlike fantasy and sci-fi, these stories aren’t massive in scope, thus making a trilogy seem drawn own. Again, there are successful lit-fic trilogies, but they aren’t the norm.
  • Horror is one of my favorite genres, but it isn’t common to see trilogies amongst these spooky books. Writing horror focuses on generating scares and overcoming or succumbing to the big scary thing. Stretching that over multiple books is a tough sell.

This doesn’t mean every fantasy story should be a trilogy, and every lit-fic tale can’t be. But read books and trilogies in the genre you like and determine whether this strategy will work for your story.

Developing the plot

Even if the spark of your big, trilogy-long story is inspired by a character or a theme, we want to develop the plot of our series first. This will help us establish our main and supporting characters, think of the settings we need, and—most importantly—determine if we have a trilogy’s worth of story on our hands.

Now, I am an avid plotter. I like outlining. Heck, I love using the Snowflake Method to get some deep outlines.

But I don’t suggest getting too intense with your trilogy outline, at least at the beginning.

On the other hand, I don’t recommend completely pantsing a trilogy. You will want to establish a few big-picture plot points and character journeys. This will let you explore as you write each book without veering so far off-course that you end up wasting time.

And it’s easy to develop our trilogy’s plot. I’ve boiled it down to three easy steps:

  1. Establish the high-level outline
  2. Determine character arcs for major players
  3. Build your fictional world

Step One: Establish the high-level outline

You can outline your trilogy however you’d like, but I strongly recommend using the three-act structure.

If you aren’t familiar with this near-universal story structure, it divides a story into three distinct sections, each with its own plot points or story beats. You can read all about it here, but we’ll also cover these beats quickly:

Act One: The Setup

  • Exposition: An introduction to your world, the main character, and their ordinary, day-to-day life (even if ordinary means fighting killer robots).
  • Inciting Incident: An event that forces the protagonist from everyday life into a new, uncertain world. They can’t return to their previous world after the inciting incident.
  • The First Plot Point: The protagonist embraces the challenge presented by the inciting incident and heads off in a new direction.

Act Two: Confrontation

  • Rising Action: A series of events that present obstacles to the protagonist. This helps them learn about their new world, make new friends and foes, and understand the larger external conflict.
  • Midpoint: Around the middle of the story (surprise!), the midpoint is a massive event that introduces a new dilemma and points your protagonist in a new direction.
  • The Second Plot Point: In response to the revelations of the midpoint, your protagonist heads off in a new direction. Their mindset switches from reactive (because they’ve just been trying to keep up with challenges so far) to proactive (where they actively pursue their big goal.

Act Three: Resolution

  • The Pre-Climax: The proactive protagonist charges towards their goal and appears to utterly fail. Here we see the full might of the antagonist, and the protagonist is forced to face their most significant weakness or shortcoming.
  • The Climax: Your hero rises from the ashes to overcome the antagonist or their biggest hurdle to achieve their ultimate goal. This should be because of the lessons they’ve learned and the skills they’ve gained throughout their journey.
  • The Denouement: Also known as the falling action, this is where your story wraps up any loose ends and lets the reader know how life goes on after the big external conflict is over.

Now that the three-act structure is mulling about in your brain, you might know where I’m going with this:

If your trilogy is one big story, it should fit into the three-act structure—and each act represents one of your books.

So outlining your high-level story looks something like…

  1. Think of the big conflict in your trilogy.
  2. Establish where your protagonist starts and the climax they’ll face at the end.
  3. Fill in the blanks using the nine beats from the three-act structure. Some beats, like the rising action, are more than one event or obstacle.

And that’s all you need to do to get started with the high-level outline.

Step Two: Determine character arcs for major players

We don’t want to get too far into the weeds with this, but it’s a good idea to get some sort of grasp on the arcs you wish for your major players.

“Major players” is just my cool way of saying protagonist(s), antagonist(s), and critical secondary characters you have in mind right now.

A character arc is the change or journey your character goes on. Where a character starts and where they end are rarely ever the same, especially when it comes to memorable characters. At this point, considering the high-level thinking we’re doing for the trilogy, think about these three different kinds of character arcs and how you might apply them to your major players.

Moral Ascending Arc - A character works to overcome their weaknesses and shortcomings to become a better version of themselves. This could be a redemption arc for a villain, an ordinary person becoming a hero, or just someone conquering their insecurities.

Moral Descending Arc - On the other hand, a character could become a worse person. This is your hero doing something morally questionable and justifying it as being for the greater good. Or maybe it’s a normal person getting a taste for power and hurting those around them to get more.

Transformational Arc - Sometimes characters just change, but their morals don’t have anything to do with it. Captain America always had good morals—he was brave, stood up for what he believed in, etc.—and his newly acquired powers put him in new situations and up against new foes, both of which test his resolve and ability to hold onto those morals.

Characters who don’t change aren’t memorable. So start thinking about how you will incorporate your characters’ changes into your trilogy. Click here for a guide to creating character arcs.

Step Three: Build your fictional world

Worldbuilding might sound like something exclusive to speculative fiction, like fantasy and sci-fi, but all genres incorporate some sort of worldbuilding.

Romance needs to establish the jobs and city our love interests are living in.

Historical fiction needs to take something that’s real and add unique, imaginative elements to it.

And then your spec-fic needs to make entire worlds either from scratch or plop it on top of our own.

Worldbuilding can be as big an undertaking as you make it. Heck, we writers have even coined the term “Worldbuilder’s Disease” to reference people who get sucked into creating fictional societies, politics, religions, and languages instead of writing.

My suggestion? Bookmark this ultimate worldbuilding guide by my pal, Abi. She walks you through everything you need to get started!

Introducing characters

Once you’ve got a decent grasp of your plot, it’s time to start thinking about your cast of characters. If you’ve been following along, there are already some character arc ideas floating around in that cranium of yours.

But we need a little more from our characters. Like who they are and why you’re including them in your trilogy. 

You’re also going to want to think about when your characters are going to join the cast. Remember, you’re writing three books here… characters, even important ones, will come and go.

That also means you don’t need to come up with all the characters right now, either. Let’s look at what characters you should start thinking of now, some nice to haves, and those you don’t need to think about yet.

Start thinking about…

  • Protagonists - I mean, the story’s all about them, right? A protagonist is the main character whose goal and journey to the goal drive the entire story. For a trilogy, this refers to the bigger story and each individual story. 
  • Antagonists - At least the big, bad villain (if your trilogy has one) and the antagonist of your first book. These might be the same people, or you might include a baddy specific to that first book.
  • Major Secondary Characters: There will be characters who share a lot of screen time with your protagonist or antagonist. You might already have some ideas for important secondary characters, their own subplots, and how they either support or hinder the protagonist. Those are the ones you should be thinking about now.

Nice to haves…

  • Minor Secondary Characters - There will be some secondary characters who you might have an idea for but don’t know exactly how they’ll work. Flesh out some of their traits, motivations, and goals so you have them ready to go when inspiration strikes.
  • Important Secondary Characters in Books Two and Three - We’re still looking at the big picture while understanding that things will change from the first sentence of your first book. Still, part of writing a trilogy is long-term planning. So get some details down about important secondary characters you are pretty sure will be coming.

Leave them for later…

  • Tertiary Characters - These are those folks who show up in a scene or two to either deliver some information for the plot or add depth to the world. At this point, when you’re just getting a handle on your trilogy from a bird’s eye view, don’t sweat the tertiary characters.

The details you want for your characters

Just like worldbuilding, you can get swept up in creating characters as easily as “accidentally” eating an entire bag of chips.

Here are a bunch of resources you can add to your toolkit, including a bunch of free resources:

Creating a timeline

Finally, you’re going to want to take everything we’ve created so far—your major story beats and your important characters—and create a timeline of big events from your trilogy.

You can do this in a variety of ways, including good ol’ pen and paper, a word processor, or keep them just one click away from your manuscripts in Dabble.

However you do it, your timeline should include the following:

  • The nine story beats from your trilogy’s three-act structure
  • Important moments or events for your character arcs
  • Other important events for your “Start thinking about” characters
  • Events that took place before the start of the trilogy

Keeping this timeline close by will give you an easy document to reference when making decisions about your three books. You can continue to add to it as you go, making it invaluable to keeping track of your series.

15 Tips for Writing Your Trilogy Books

So you have a lot of action steps to prepare you for your trilogy, which I hope will help get you started. But you’re going to get to the point where you need to write your books!

A lot of the steps and knowledge you need will be the same as writing a standalone book. You can find a metric ton of resources over at DabbleU for that (for absolutely no cost, of course).

For a trilogy, there are some specifics you’re going to want to keep in mind.

So here are fifteen tips—five per book—for writing your trilogy.

5 Tips for Writing the First Book in a Trilogy

The first book of your trilogy does a lot of heavy lifting. It’s the entrance to the other two books, the hook for your masterpiece. Not to hype it up too much, but it’s incredibly important.

Tip One: Establish the World - Remember how the beats of your trilogy’s three acts line up with the three books within it? It’s the first book’s job to establish the world you’ve created. This means your reader should learn about major societal norms, events, people, culture, and conflicts. You’ll add more as the story progresses, but the bulk should be introduced in this first novel.

Tip Two: Introduce the Protagonist and Antagonist - You’ll add in important secondary characters in this book and the remaining ones, but your reader should have a firm grasp on the personalities, goals, and motivations of your protagonist and primary antagonist.

Tip Three: Introduce and Resolve a Book-Level External Conflict - Remember, each story in your trilogy should introduce and resolve its own external conflicts while contributing to the larger conflict that spans your trilogy.

Tip Four: Balance a Complete Ending with a Cliffhanger - Whether you’re a fan of cliffhangers or not, your first book needs to end in a way that makes your reader insatiable for the next one. At the same time, your ending needs to be satisfying in its own right.

Tip Five: Make it the Best it Can Be - In any series, your biggest drop in readthrough will be from book one to two. Yes, every book deserves your best effort, but book one really needs to captivate your reader to suck them into your trilogy.

5 Tips for Writing the Second Book in a Trilogy 

At first glance, you might think the second book isn’t working as hard as the other two. It’s not introducing the series or giving us the huge, climactic ending.

But the second book, just like the middle of any story, risks turning into a bit of a slow, boring read. We don’t want that.

Tip One: Determine How Much Time Has Elapsed - Where did you end the story in book one, and how much time has gone by between then and the start of this book? It could be seconds, hours, days, months, or years. Consider how this impacts your bigger story and the reader’s experience. Ask yourself how these would change if your timing changed.

Tip Two: Continue Major Character Arcs - There should have been progress for major players in book one, but their journey should continue in book two. Remember, you’re telling a story bigger than one novel. That should be reflected in your characters’ arcs.

Tip Three: Introduce New Internal and External Conflicts - And make sure they complement the overall narrative and larger conflicts. These should almost be like sub-conflicts but still stand on their own as something worthy of an entire book.

Tip Four: Develop Secondary Characters - The benefit of a trilogy is that it allows you to add more depth to your characters, even if they aren’t the main ones. Use this to your benefit and make your readers fall in love with (or utterly despise) some of your secondary characters.

Tip Five: Vary the Cast - As I mentioned before, it’s a good idea to add new characters throughout your series and remove some older ones. Remove could mean sending them elsewhere for part of the story, writing them out, killing them off, etc. Varying your cast helps to keep things fresh for your reader and allows them to get excited all over again. Just make sure to retain those core players.

5 Tips for Writing the Third Book in a Trilogy

Then we get to the epic finale of your trilogy: book three. All things have been building towards this book. You want the lasting impression to be a good one and to pay off everything your characters have been working for.

Tip One: Start to Wrap Up Plot Lines - Any long-running plot lines or character arcs should start wrapping up throughout your book. Don’t save them all for the end; not everyone’s goal will be the same as your protagonist’s big objective. Start giving closure and showing how your characters have changed.

Tip Two: You Still Need Conflict - Yes, this book will wrap up the big external and internal conflicts, but there should still be other obstacles getting in the way. Remember, your trilogy’s conflict doesn’t replace your book’s conflict.

Tip Three: Callbacks to Book One - If there were some great characters, locations, items, or moments in book one that weren’t referenced in book two, bring them back in book three. Again, it doesn’t have to be all at once, but your reader will appreciate seeing them again.

Tip Four: No Cliffhangers - We didn’t come this far for another cliffhanger. Even if this trilogy connects to another, don’t have some big cliffhanger ending. If your readers expect your bigger narrative to be wrapped up in book three (because it’s a trilogy), wrap it up.

Tip Five: Go Big - Whether your readers have been waiting days or years for the finale of your trilogy, you want it to be worth their time and dedication. These are now your fans. Go big in the climax of this book and the bigger story. Have fun. Deliver everything you’ve promised.

The Best Way to Write Your Trilogy

If you’ve stuck with me through this entire article, you might feel like you’ve just read a trilogy’s worth of advice. But writing a series of three books isn’t easy. The fact that you’re going for it is commendable.

So I commend you.

If you want a novel-writing program that makes writing a trilogy (or any book) easier, you’ve stopped by the right place. Dabble not only lets you write anywhere, on any device with automatic backup (who hasn’t lost hours of work from not saving?), but it has built-in features that help you write multiple connected books.

Under one project, you can house your manuscripts for each book, create a famous Plot Grid for each one, and keep all your character, worldbuilding, and random notes just one click away, no matter which book you’re currently on.

The best part? You can try it for free, no credit card required, by clicking here. Happy writing, dear author, and go kick that trilogy’s butt.

Doug Landsborough

Doug Landsborough can’t get enough of writing. Whether freelancing as an editor, blog writer, or ghostwriter, Doug is a big fan of the power of words. In his spare time, he writes about monsters, angels, and demons under the name D. William Landsborough. When not obsessing about sympathetic villains and wondrous magic, Doug enjoys board games, horror movies, and spending time with his wife, Sarah.