
You’ve nailed down your main character and constructed a worthy adversary and now need to flesh out the cast and people your book. You need more characters.
Well-developed supporting characters help to create a more rounded protagonist and reinforce the story between the protagonist and the antagonist. Supporting characters work in harmony with the main character to propel the plot forward and to facilitate growth, change and conflict. Supporting characters can challenge the protagonist’s world view, teach and mentor, encourage, inform, harm, betray, and love. They help make the main character become who you, as the writer, want them to be.
A supporting or secondary character’s purpose is to support the protagonist. And just because they may have a minor role in the story does not mean that the development of these characters is less important. Each character needs to be distinct, their roles, purposes and functions defined.
The following 5 types of supporting characters can help you populate the pages of your novel. These types of characters are intended to further the plot and help the protagonist achieve his/her goals. You may use any number of each type of character that you need to create a compelling narrative.

1. BEST FRIEND
a.k.a Confidant, Supporter, Caregiver, Sidekick
The Best Friend is the one to whom the central character talks and who helps to reveal motivation, fears, and goals. The Best Friend helps the protagonist understand their flaws and work to overcome them through challenging their decisions and attitudes (Piglet, Winnie-the-Pooh). Often through these challenges, the bond between Best Friend and protagonist will be weakened for a time, but because of common goals and through the protagonist’s growth, the two will be reunited and the bond strengthened (Diana Barry, Anne of Green Gables). The Best Friend will do everything in his/her power to support and help the main character achieve their ultimate goal.
The Best Friend may also function as the comic relief or lend contrast to the protagonist.
Examples: Ronald Weasley, Harry Potter series. Samwise Gamgee, The Lord of the Rings. Charlotte Lucas, Pride and Prejudice.

2. CHALLENGER
a.k.a. Antagonizer, Provoker, Henchman
A Challenger can be the villain’s henchman or minion, but the function of this role does not necessarily have to be interpreted as “bad guy”. A Challenger is the antithesis of the Best Friend. He/she can test the protagonist’s choices and make them question their competence, decisions and goals. Their goal is to provoke, antagonize, anger, annoy, demean, aggravate, displease, and irk the protagonist in any way possible, thus providing conflict to the main character.
The Challenger can be useful in creating rising tension and stakes but is not the focus of the final conflict. Often the Challenger is a lesser villain the protagonist needs to overcome before the final conflict with the antagonist (Count Rugen the 6-fingered man, The Princess Bride). Overcoming the Challenger may be accomplished by a Best Friend, or Informer and not directly by the protagonist. The main character can have mixed feelings (annoyance, pity) toward the Challenger and may try to redeem them.
Examples: Draco Malfoy, Harry Potter series. Gollum, The Lord of the Rings. Mr. Collins, Pride and Prejudice.

3. INFORMER
a.k.a. Mentor, Teacher, Technician
The role of the Informer is to provide information to the protagonist that will further the plot. This can come through instruction, inspiration, guidance, technical information, revelations, or gossip. The Informer may teach and mentor in order that the protagonist will have the abilities and knowledge to overcome difficulties (Mr. Miyagi, The Karate Kid). Or he/she may contribute knowledge that the protagonist needs to further his/her goals (Inspector Lestrade, The Adventures of Sherlock Holmes). An Informer may be a passing character, strictly there to convey specific information, or may be a central character in the protagonist’s life influencing decisions.
A sub-type of Informer is the Tech Wizard or Techie. This Informer will provide tools to help the protagonist achieve their goal and become an improved version of themselves (Q, James Bond series. Cinna, The Hunger Games). The Tech Wizard also includes hackers, scientists, weapon specialists and inventors.
Another sub-type of Informer is the Thematic character. A Thematic character is someone who carries the theme or message of the story. They may explicitly state it like Uncle Ben from Spiderman (“with great power comes great responsibility”) or Ian Malcolm from Jurassic Park (“life finds a way”).
Examples: Albus Dumbledore, Harry Potter series. Gandalf, The Lord of the Rings. Mrs. Gardiner, Pride and Prejudice.

4. BETRAYER
a.k.a. Shapeshifter, Deceiver, Double agent
The Betrayer is a character that shifts from one role to another. Their role is to mislead or deceive the protagonist and the reader which may include a surprise twist and create conflict. The Betrayer may be revealed in the end and be integral in the outcome of the protagonist’s story (Brutus, Julius Caesar) or discovered early in the narrative and essential to the protagonist’s motivation and goals (Fernand Mondego, The Count of Monte Cristo). The Betrayer may betray the protagonist or the antagonist, as long as his/her main role in the beginning of the novel is different from the role at the end.
Examples: Severus Snape, Harry Potter series. Saruman, The Lord of the Rings. Mr. Wickham, Pride and Prejudice.

5. LOVE INTEREST
a.k.a. Lover, Admirer, Companion
The function of the Love Interest is to be the romantic attraction to the protagonist. The range of influence of this character is wide and will vary on the genre and style of story you are writing. Every story can benefit from having a Love Interest, however limited or fleeting, and this type of character is not limited to Romance where the plot revolves around a romantic relationship. The relationship can be in any stage from unrequited (Laurie and Jo, Little Women) to widowed (Ellie and Carl, Up). Often this character performs another of the supporting roles as well as the Love Interest.
Occasionally the Love Interest does not fill a romantic role, such as in a “buddy” story (Harry and Lloyd, Dumb and Dumber. Agent J and Agent K, Men In Black). This sub-type of Love Interest still follows the Romantic plot arc of mutual interest, conflict, bonding, separation, and reunion.
Examples: Ginny Weasley, Harry Potter Series. Samwise Gamgee, The Lord of the Rings. Mr. Darcy, Pride and Prejudice.
Supporting characters are like a symphony behind the first-chair soloist playing the melody. They add a variety, depth and richness to the song that one instrument couldn’t hope to achieve on its own. Each instrument fills a need in the orchestration, they manifest harmony, discord, transformation, and resolution. With each instrument’s contribution and support of the soloist and melody the song becomes whole. And with the proper conducting, a master work is created.

Questions to Fine-Tune Your Supporting Characters
- Does this character fill a role and a have a purpose in the story? What type of supporting character is he/she?
- Is this character’s role also filled by someone else? If yes, should this character be eliminated or merged with another character?
- Does this character feel stereotypical? If yes, what can you tweak in the character’s sociological, physiological, and psychological characteristics to make them a type, not a stereotype?
- Does this character’s relationship with the protagonist move the plot forward?
- Does this character have his/her own unique personality? Does he/she have a life and voice of his/her own independent of the protagonist?
- How does this character’s world view differ from the protagonist? How is it the same?
- Does this character have his/her own goals and motivations?
- Does this character influence the protagonist and the decisions he/she makes?
- Do the scenes in which this character appears overpower the protagonist’s POV? If yes, how can you shift the scene back to the main character? If this is a recurring issue, does this character need to be the main character instead?
- Do you know this character well enough to have them tell their own story? If yes, consider a spin-off or sequel that features this character.