How to Outline a Complete Book Series
Whether you’re planning a duology or a 12-book series, let’s break down the three types of novel series and how to outline each one.
Book series are fun.
Sure, standalone novels are great. But sometimes, they don’t quite hit the spot.
Often, writers like you may feel like your stories are far too big to be contained in just one book. Or maybe your existing readers are begging for adventure after adventure with your unforgettable cast of characters, especially that villain they just love to hate. And, of course, book series are a wonderful way for writers to keep readers engaged and driving sales.
But as exciting as writing a series sounds, you might be wondering: How do I start? Outlining one book is hard enough. How am I going to outline multiple stories? And what’s supposed to happen on the pages of each individual book?
Let’s figure out which type of series best suits your story and how to outline each type.
Types of Book Series
Episodic: a multi-book series following the same protagonist through a new conflict, not meant to be read in order
Interlinked: a multi-book series following new protagonist(s) through a new conflict, not meant to be read in order
Serial: a multi-book series following the same protagonist(s) through a continued conflict, meant to be read in order
Episodic Series
An episodic series is a multi-book series composed of the same protagonist or cast of characters in self-contained books, not meant to be read in any particular order. This series type is also referred as a static or procedural series. Although the type of conflict is generally the same in each book (i.e. a mystery), the specific antagonist or antagonistic force changes in each book (i.e. Murderer #1 in Book 1, Murderer #2 in Book 2).
Episodic series examples include Hercule Poirot’s crime solving adventures in Murder on the Orient Express and Death on the Nile by Agatha Christie, the Nancy Drew Series by Carolyn Keene, and the Sherlock Holmes Series by Arthur Conan Doyle. The most popular genres for this series are crime and mystery.
How to Outline an Episodic Book Series
Create a compelling and consistent main character
The most important element of an episodic series is the recurring protagonist because they are the only constant. That means the main character needs to be compelling enough to anchor the series. Readers will either love them or hate them (or a mix of both), but regardless, they’ll keep returning to see what new shenanigans your leading character will stumble into next. A compelling character is someone who has a careful balance of strengths and flaws, and is active enough to push the narrative forward.
Can an episodic series have multiple protagonists? Yes. You can have one protagonist with a regular crew of secondary and tertiary characters, just like Nancy Drew and her friends “Bess” Marvin, George Fayne, and Ned Nickerson. And you can have multiple protagonists, like Scooby Doo, Shaggy, Velma, Daphne, and Fred. Although if you have a new protagonist in each book, you might have an interlinked series on your hands instead.
Your protagonist should also be relatively static: same general personality and same general role in each book. That way, a reader can crack open any book in your series to experience their favorite protagonist defeating the new villain du jour—without feeling like they’ve missed out on any important backstory or character arcs from previous books. If your protagonist is a grumpy sleuth in the first novel, that’s what they’ll be for the next ten or twenty novels to follow. Readers will be confused if your grumpy sleuth suddenly decides to start a matchmaking business in the eleventh installment and adopts a cheery personality.
That said, there’s some wiggle room to include smaller character arcs for the protagonist. The important thing to remember is that these mini arcs shouldn’t affect the order in which your audience can enjoy reading each book, otherwise you’re likely writing a serial series instead. Think of these mini arcs as a bonus. The arcs are just enough to reward readers for reading so many books within your series.
For an example of a mini character arc, let’s look at the Hercule Poirot movies based on Agatha Christie’s detective novels, in which the clever and sassy detective Hercule Poirot is our constant main character. The movies and books are similar, but the movies add in a mini character arc for Poirot. Why? Perhaps because the filmmakers realized just how much modern viewers appreciate character depth and steady growth. In A Haunting in Venice, Poirot’s job is to solve the mystery. But at the same time, he’s experiencing small character shifts and revealing layers of his backstory. At the start of the movie, Poirot declares himself on vacation and refuses to consult with desperate townspeople in need of his one-of-a-kind sleuthing skills. By the end of the story, his solved mystery influences him to change his mind and he takes on a new case with more enthusiasm, thus cutting his vacation short. This is a great example of featuring a mini arc in one book.
But these mini arcs can also span several books. In Murder on the Orient Express, viewers learn Poirot had a wife named Katherine who died on a train and he is finally learning to grieve her death. Then in Death on the Nile, Poirot meets a character who challenges his romantic abstinence and helps him realize that he actually is willing to reconsider love again. These mini arcs do not affect the main plots of either movie, so the viewing order still doesn’t matter. The arcs just sprinkle in some fun details that faithful viewers will appreciate as the series continues.
So, while your main character might not have a significant arc of change over the series at large, static protagonists should still be compelling and can experience mini arcs of change.
Compose a detailed character sheet with the following details:
Who is your protagonist / protagonists?
Where are they from? Where do they live now?
What experiences and beliefs have informed the person they are today?
What makes them unique?
How do they respond to conflict? Fear? Love? Making mistakes?
What kind of conflict do they chase after (or find themselves in) with each book?
Who are their supporting characters, if any?
Plot each book individually
Once you have a protagonist strong enough to build your series around, you’re ready to craft several thrilling plots to draw out your protagonist’s unique traits. Although the specific plots are going to change from book to book, the type of conflict should remain the same each time. So, if you’re writing a series of mysteries, each plot should be a mystery and not an action or romance plot.
Each book’s plot will also be self-contained, with a clear beginning, middle, and end. If a mystery begins in Book 1, it will be solved in Book 1—not Book 2 or 3.
What will each story’s plot be? Take some time to brainstorm all the wonderful ways your character could face conflict. Be as imaginative as you’d like. If you have a historical detective, research the designated era to make a list of all the various killers and murder methods that existed. Be careful no to self-edit in the brainstorm phase, as you can select the best ideas later.
Consider:
What elements will I keep the same in each book, and what will I change?
Will I always use the same city, or will I use a different location each time?
What will each new conflict help me reveal about my main characters?
Which plots could pair with which mini arcs, if I want to include those?
What general plot formula is the best for my series?
Determine a timeline of events
That last step is assembling these plots into a loose timeline of events. While you don’t need to release each novel in chronological order of your protagonist’s life, you’ll need an understanding of passed time. Because if your series has mini character arcs that progress from one book to another, reading the books in publication order might offer a more comprehensive view of the character’s growth or relationships. Also, if you have two plots that feel quite similar (i.e. two mysteries about two different Midwestern serial killers), you can space those out with a book or more in-between.
When does your series have to end? Whenever you want. You can write as many books as you think your protagonist has to tell.
Create a timeline and place each book on that timeline in a general order that works best for your story. While you’re doing this exercise, consider:
When does each backstory event occur?
How old is each member in my cast of characters?
Will they age as the series moves forward?
Will the series cover a year of their life? A decade? Longer?
If I am going to reveal certain Easter eggs, what does the correct order of books need to be?
Interlinked Series
An interlinked series is a multi-book series composed of a cast of characters in self-contained books, not necessarily meant to be read in any particular order. Just like an episodic series, readers can pick up any book in any order. As long as each story is linked by the same umbrella universe, theme, and genre, then each book can portray a different protagonist, era in time, or antagonist.
Interlinked series examples include the various Tortall Series by Tamora Pierce, including The Immortals Series, Song of the Lioness Series, Protector of the Small Series, and The Circle of Magic Series where each series follows one protagonist or set of protagonists in different areas and eras of the Tortall world.
Other examples include The Giver Series by Lois Lowry, the Bridgerton Series by Julia Quinn, and The Century Trilogy by Ken Follett. Each series explores a new protagonist (though they may feature some of the same characters as other books), while remaining under the same thematic throughlines, unique worldbuilding and settings, or even family lineage.
How to Outline an Interlinked Book Series
Define an immersive overarching world
Just like an episodic series, your interlinked series won’t have an overarching storyline. Although this time it’s your unique world that will connect each book loosely together, not a constant protagonist. Readers want to immerse themselves in your worldbuilding, using each new installment to explore the world with new characters, conflicts, and storylines.
Create your series world and pay attention to consistency with each element.
Consider:
What overarching themes will every book explore?
What is the overarching world that each of your books will take place in?
If my world has magic or a similar set of unique laws of physics, how do these elements function consistently throughout my world?
If my world is based in historical realism, how does each book connect to the overarching timeline of world events?
Who are the different characters I’d like to explore?
Plot each book or mini-series individually
With an interlinked series, you have two options: you can write a standalone book within a series or a standalone series within a larger series.
To give an example of a series within a series, we can take a page out of Cassandra Clare’s novels. Her entire universe is called the Shadowhunter Chronicles, yet she has several series within that universe. For example, The Mortal Instruments series follows Clary Fray through modern-day New York City, while The Infernal Devices trilogy is set in the same universe but follows Tessa Gray in Victorian London. There are several characters that crossover into both series, but these series are distinct from one another. Both Mortal Instruments and Infernal Devices are serial series, connected to one another through the overarching interlinked series Shadowhunter Chronicles.
Other examples of book series within larger series might include J.R.R. Tolkien's The Lord of the Rings series and The Hobbit, or Brandon Sanderson's works set in the Cosmere universe.
If you choose to write a series within a series, you need to learn how to outline both an interlinked and a serial series (see the last series type below).
Interlinked series are also a great place to drop subtle “Easter eggs”. These eggs are narrative ties between one novel and another. Although you’ve probably heard this term used with one work of fiction referencing another work of fiction by a different author (i.e. Director Steven Spielberg references The Shining by Stephen King in the movie Ready Player One), they can also be used with the same author’s works.
For example, in Lois Lowry’s Giver quartet the overarching tie between the books is thematic: all societies are controlled by oppressive dystopian governments. And each book features a separate plot with new characters. Lowry’s “eggs” are when some of the beloved characters from previous books reappear in the subsequent books. For instance, Gathering Blue has a character named Matty who reappears as a significant character in the subsequent book Messenger. This connection creates a sense of continuity within the series by linking characters and events from one book to another.
To plot each book, dive deeper into each aspect of your world you’d like to explore. Make sure each book sticks to the “rules” you’ve created for your series at large.
Consider:
Which characters, if any, will I continue to feature in upcoming books?
What small elements, if any, do I want to plant as Easter eggs in my series?
How can I explore the overarching themes in new ways throughout each book?
If different from one book to another, what are the unique settings in each book within the overarching world I’ve established?
For each new conflict, which character or cast of characters are the best ones to tell this story?
Determine a timeline of events
Although episodic series can theoretically go on forever, interlinked series are typically more grounded in time. The story isn’t glued to the same character each time, so you have room to explore either different physical corners of your universe in the same timeframe or the same physical location across various eras, or a combination of the two. In any case, a timeline is crucial for making sure each story you write adheres to your unique worldbuilding with it’s rooted history.
And if your story spans any significant length of time, you’ll need to organize the order of events, whether your story’s world is real or imagined. For example, in The Century Trilogy by Ken Follett, his three books chronologically span a significant period of time, covering key historical events across the 20th century from the start of World War I all the way to the start of the Vietnam War. Each book loosely follows the descendants from the book before, while also introducing new characters for readers to follow. Since Follett’s series is based off a real time period, he had to research the various dates of various historical events to reflect the changes in his chronological series.
Similarly, Suzanne Collins created a sturdy timeline for her various interlinked series in the imaginary world of Panem. The Hunger Games series featuring protagonist Katniss Everdeen takes place further along the timeline, while A Ballad of Songbirds and Snakes (an interlinked standalone novel) and Sunrise on the Reaping (another interlinked standalone novel) both take place years before Katniss Everdeen was born. Because of Collins’ clear timeline, she is able to choose which protagonist’s story she wishes to tell and in which order.
As you create your own timeline, consider:
When does each backstory event occur?
When do major political events happen that span portions of my world or the entirety of my world?
How old is each member in my cast of characters from one book to the next?
How many days, months, or years will my series span?
If I am going to reveal certain “Easter eggs”, what does the correct order of books need to be?
Serial Series
A serial series is a multi-book series following one overarching storyline across all volumes, meant to be read in order. Think of a serial series as one large book split up into mini books, intentionally divided at just the right moments in order to keep readers hooked. This series is also referred to as a dynamic series.
Serial series examples include the Game of Thrones Series by George R.R. Martin, the Harry Potter Series by J.K. Rowling, and Wintersong duology by S. Jae-Jones. They’re commonly found in fantasy, but work with every genre.
How to Outline a Serial Book Series
Out of all three series types, serial series involves the greatest amount of planning because they have the tightest points of connection between each book. Each book simply cannot exist without the context of the other. And readers stick around for the grand finale, which also means the series cannot go on forever.
Define your protagonist and their character arc
Similar to an episodic series, your series will follow a set character or cast of characters. However, your main characters, especially your protagonist, should be far more dynamic than the relatively static leading detectives like Nancy Drew or Sherlock Holmes. Dynamic characters must grow, worsen, and ultimately change in a big way by the final book in your series—externally, internally, or (preferably) in both ways.
For example, in the The Hunger Games series, our protagonist Katniss Everdeen changes significantly from Book 1 to Book 3. Physically, she becomes stronger, faster, and more agile, while also incurring several injuries. Emotionally, she falls in love with both Peeta and Gale. And ultimately, Katniss becomes more assertive and plays a major role in overthrowing the oppressive Capitol.
Create a character sheet for your each of your main characters. For your primary protagonist, determine their overall character arc from series start to end. If you have several protagonists, create separate character sheets with their unique character arcs as well. As you go, consider:
Who is my protagonist / protagonists?
Where are they from? Where do they live now?
What experiences and beliefs have informed the person they are today?
What do they want most in the world?
What is their biggest flaw or false belief?
Over the course of 2 or more books, how will the protagonist physically, mentally and emotionally develop to reach the end?
Establish your overarching plot
Unlike the other two series types, the main draw of a serial series is the overarching plot. While each book within the series will have a mini-plot, they each build up to the main storyline’s final showdown. And the showdown shouldn’t happen until the climax of the final book.
That means that not only do you need an overarching plot, you need a plot for each book, too.
The good news is that both the overarching and individual plots are created in the same way. Each one needs a clear beginning, middle, and end—just like every story unit. To establish the foundational plot points of the overarching story first, it’s time to get a clear idea of how the entire story starts and ends.
Before we get into your overarching story, let’s look at the overarching story from The Hunger Games series by Suzanne Collins. Here’s how the plot works on the highest level throughout all three books:
How does The Hunger Games series begin?
In Book 1, readers are introduced to a dystopian society known as Panem, where protagonist Katniss Everdeen volunteers to take her sister's place in a deadly televised competition called the Hunger Games.
How does the series end?
In Book 3, everything ends with the overthrow of the oppressive Capitol, where Katniss Everdeen plays a pivotal role in the rebellion's success.
What is the final series climax?
A high-stakes battle in the Capitol in Book 3, leading to the downfall of President Snow and the victory of the rebel forces.
How does the protagonist grow and change by the end?
Katniss Everdeen evolves from a reluctant tribute in Book 1 into a symbol of rebellion and hope in Book 3, facing personal challenges and sacrifices along the way.
Now you can work with the character sheet you already created to plot the main events of your overarching story. You can be as specific as you’d like, but at this point you only need a general direction.
Consider:
How does my series generally begin?
How does my series generally end?
What will my final series climax be?
Over the course of 2 or more books, how will my protagonist(s) grow and change by the end?
Select the number of books you need
Remember that a serial series cannot go on forever. Everything builds to a final climax, so you need to deliver a set number of books to expectant readers. While that number won’t always be set in stone, you’ll have a smoother planning process if you can pin down a general estimate now.
To determine how many books your series needs, consider how big the overarching plot is, how much time you can allot to writing the series, any deadlines your agent or editor may have for you, and how much life you can squeeze out of your story and its characters.
If you plan to query your book series and do not have an agent or publisher yet, I recommend writing the first book in the series as a standalone with series potential, instead. Agents and publishers sometimes struggle to sell a book series, especially for debut authors. If you are serious about traditional publishing and are open to pitching your story as a standalone, don’t end your querying manuscript with a cliffhanger. Have a clear idea of how you want the series to continue, though, so you can discuss options with your future agent and publisher.
Once you have an idea of the number of books in the series, you might wonder how you could possibly decide which content should go into which book. Sure, you’ve got the overall plot nailed down, but which parts go where?
Don’t panic. There are a few standard guidelines you can use for your series:
The inciting incident for the entire series will typically fall at the end of the first book during the climactic moment.
The midpoint of the series will often be the middle book of the series (or the middle books if there’s an odd number of books in the series).
And, always, the third act for the entire series will fall in the climactic, super high stakes finale of the final book of the series.
Look for natural mini plots within your overarching story. For example, if your protagonists must complete a training program in order to prepare for a final battle with the antagonist, separate each book into a year at their training academy. Just like Rebecca Yarros does in the first two books of the Empyrean series where protagonist Cadet Violet Sorrengail tries to survive both year one and year two of dragon riding school.
You can also use a repetitive plot structure, like J.K Rowling does with her first six books in the Harry Potter Series: Harry goes to school for the year, faces conflict from Voldemort and defeats him for now, repeat. Similarly, Suzanne Collins repeats the Hunger Games set-up in her first two books: Katniss prepares for the Hunger Games, she survives, repeat. In the end of both of these series, the protagonist and their team face the major antagonist in one final determinative battle at the height of the series’ intensity.
When it comes to breaking down the overarching series into each book, writer Jessica Brody uses the three-act structure to suggest possible series splits based on book count:
Plotting a duology:
Book 1 is Series Act 1 and Act 2A (up until the midpoint)
Book 2 is Series Act 2B and Act 3
Plotting a trilogy:
Book 1 is Series Act 1
Book 2 is Series Act 2
Book 3 is Series Act 3
Possible series beat sheet for a quartet:
Book 1 is Series Act 1
Book 2 is Series Act 2A (up until the midpoint)
Book 3 is Series Act 2B
Book 4 is Series Act 3
Possible series beat for pentalogy:
Book 1 is Series Act 1
Book 2-3 is Series Act 2A (up until the midpoint)
Book 4 is Series Act 2B
Book 5 is Series Act 3
Choose how many books in your series you’ll need and plot the foundational plot points on a timeline that works best for your story.
Consider:
Which book will contain the series inciting incident?
Which book/s will span the second act of my series?
Which book will contain the series climax and resolution?
Define each book’s mini plot
Each book needs to build towards the final book in a big way, and they must put the protagonist through a mini character arc until they complete their overarching character arc by the final book.
Don’t forget that each book should increase the intensity, as well. Be sure to keep the overall tone consistent by working under the same umbrella theme, planting foreshadowing and hints for the final installment of the series, and establishing the same mood.
Once again, let’s analyze the foundational plot points of Suzanne Collins first novel in The Hunger Games series:
How does Book 1 begin?
The series begins in a dystopian world where protagonist Katniss Everdeen volunteers for the annual Hunger Games to protect her sister, Prim. These games are nationally televised events in which two tributes from each district battle to the death, and only one victor survives.
What is the climax in Book 1?
The climax occurs during the final moments of the Hunger Games when Katniss and Peeta threaten a double suicide, challenging the Capitol's authority and forcing them to declare two winners instead of one.
How does Book 1 end?
Both Katniss and Peeta survive as joint victors of the Hunger Games for the first time in history. They have survived the story’s main conflict for now, though the threat of the Capitol looms over them.
Over the course Book 1, how does the protagonist grow and change by the end?
At first, Katniss cares only about the survival of her family and district. As the story progresses, she learns more about the Capitol’s oppression and forms new relationships with other tributes. By the end, Katniss defies the Capitol's rules, showing her newly fledged willingness to challenge authority as well as an acceptance that survival is important—but not the only thing that matters in life. Love, friendship, and justice are important, too. She has not completed her entire arc for the series as a whole, but by the end of Book 1, she has taken a large step forward.
Something else to consider is how each book’s plot will bleed into the next book’s plot. Writers often accomplish this with cliffhangers. These are a great way to entice readers to gear up for the next installment, though it’s important that any cliffhangers occur after the individual book’s resolution comes to an end.
Repeat the process you used to outline the overarching plot for each book’s mini plot. If you have multiple POV protagonists within each book, you’ll need an additional outline for each character.
How does mybook begin?
What conflict will my protagonist face throughout the book?
What will my climax be?
How does my book end?
How will the main conflict in this book lead to the main conflict in the next book, and therefore propel readers to read more?
Pick good titles
Choosing a strong, resonant title for each book in a book series is important, because you want the series to feel cohesive under one naming structure. You can use your character’s name, or you can plug-and-play different words in a recurring naming formula. Check out some popular naming styles:
The Divergent Series by Veronica Ross: Divergent, Allegient, Insurgent
A Court of Thorns and Roses Series by Sarah J. Maas: A Court of Thorns and Roses, A Court of Mist and Fury, A Court of Wings and Ruin, A Court of Frost and Starlight, A Court of Silver Flames
The Nancy Drew Series by Carolyn Keene: The Secret of the Old Clock, The Hidden Staircase, The Bungalow Mystery, etc.
Your series title will most likely reference the core conflict, theme, or characters throughout your story. For example, the regency-era romance saga The Bridgerton Series is aptly named after the shared family name.
Bonus tip for serial writers:
With each new book in your series, make sure you find the most interesting and timely ways to recap the previous book events. While we’ve established that these books are not standalones, readers should be able to navigate each new book in the series with enough context to make up for any details they’ve forgotten.
Closing Thoughts
And voila! No matter what kind of series you’re writing—episodic, interlinked, or serial—you now have a clear roadmap to outlining your dream novel series.
Need more help plotting your book series? Download my free resource to step-by-step outline your series whether you’ve got a duology, trilogy or twelve-book saga.
