6 Ways to Create Amazing Character Chemistry

I’ve been thinking a lot recently about character chemistry—that spark, bond, or shared connection we often associate with strong and compelling romantic relationships.

But chemistry shouldn’t be limited to love interests. Frodo and Sam, Thelma and Louise, Luke Skywalker and Darth Vader…some of the most memorable relationships in fiction had nothing to do with physical attraction. If we can bring chemistry into the protagonist’s friendships, rivalries, or even mentor/protégé and adversarial relationships, the characters and dynamics will come alive for readers.

So I’d like to share six tips for creating that oomph between characters in any genre.

1. Make the Characters Clash

Tension—the reader’s emotional response to what’s happening with the character—is a key element of chemistry and can be generated through conflict, suspense, uncertainty, and anticipation. When we examine tension within the context of relationships, it often arises through the interplay between the characters.

Even positive and symbiotic relationships need tension to keep them moving. So give the characters opposing traits—impulsive vs. cautious, logical vs. intuitive, tolerant vs. inflexible—to create that sense of strain. Maybe they have conflicting goals, or they’re pursuing the same objective but for different reasons. Are they opposed when it comes to certain questions of morality or ethics? Differences create friction, and friction creates interest. So make sure your characters challenge each other simply by being true to themselves.

2. Let Them See Each Other Clearly

Everyone wants to be seen; it’s something we look for in our real-world relationships, so adding that element to a fictional dynamic can give it an extra dose of authenticity. Maybe one character sees something in the other that most people miss: an undervalued strength or how they’re uniquely different. Maybe the character sees a friend’s flaws and weaknesses and are able to call those out in a way that’s challenging rather than critical. This depth of knowing each other speaks to a deeper kind of relationship that most readers appreciate and will respond to.

3. Don’t Forget the Subtext

I recently rewatched the TV show Lie to Me, and in the first episode, the protagonist claims that people on average lie three times per hour. I don’t know if that’s true, but it feels true. Whether we’re lying outright or covertly being deceptive (leaving out details, pretending to feel something we don’t, etc.), no one is completely honest all the time.

Authentic characters hide things: their true feelings or opinions, what they really want, their insecurities and fears—even from the people they love and trust. So a character’s surface-level interactions (their words, choices, and behaviors) contradict what’s really going on inside (visceral responses, thoughts, and emotions). That subtext charges the energy in the relationship, making it crackle.

This kind of chemistry is compelling to readers because it adds a sense of realism to the relationship. It also creates intrigue as the reader sees everything isn’t as it seems, and they start paying closer attention to figure out what’s happening under the surface.

4. Create Shared History or Inside Moments

Chemistry builds on shared experiences—good and bad. When you’re creating characters and their important relationships, add in backstory events that reveal a bond. When they reference those touchpoints, it reveals a depth to their relationship. If the characters are just getting to know each other and don’t yet have a history, create bonding moments—even something small, like a shared joke or win—to start building that depth early.

5. Make the Relationship Interesting

Chemistry is anything but boring, so it’s hard to find it between boring, predictable, or clichéd characters. What can you add to the relationship to make it unusual or interesting?

• As discussed, make the characters clash through opposing traits, goals, or morality.
• Unify them in a difficult objective.
• Make the pairing itself unusual, as in the case of a high school chemistry teacher and his student joining forces to make meth.
• Give them a powerful joint enemy in the form of an individual, organization, a natural or supernatural force, or even the society or culture they live in.
• Add mystery. One of my favorite pairings in all of fiction is the one between Scout Finch and Boo Radley. Their relationship teems with chemistry despite them not talking or officially meeting until the very end. They were separated for most of the story, but the tension, energy, and spark were there because of the mystery surrounding Boo Radley.

Relationships are only as engaging as the characters who embody them, so invest ample time and energy in the character creation process to be sure you’re building a unique and authentic cast that readers will find interesting.

6. Add Ebb and Flow

Chemistry is very much about shifts and changes. A relationship where both parties are content and comfortable and everything stays the same will read as flat. One way to address this is to map out the relationship arc—all the characters’ interactions—throughout the story. Mark those events with a + or – sign to indicate strengthening (increased admiration, proven trust, bonding through adversity) or a decline (increased distance, an argument, loyalty being questioned). If you don’t see changes (if the relationship is mostly flat) add moments that create movement. This will keep it from stagnating, giving the relationship a sense of flow and evolution.

Basically, chemistry emerges not only from what the characters say and do, but through how they engage with each other. Big moments have big impact, but you can only have so many of those in a story. Capitalize on the small things that can bring about friction, camaraderie, subtext, and uncertainty in the relationship, and readers will be drawn in.

Build the relationships—healthy, toxic, and in-between—that your character needs

Check out our comprehensive Relationship Thesaurus at One Stop for Writers. These entries will help you plan each connection with intention, showing how the relationship shapes a character’s choices, sparks meaningful attachments or points of friction, and ultimately drives the story forward.