Part 3: Action-reaction in fiction as Newton’s Literary Third Law

“For every action, there is an equal and opposite reaction…” Newton’s Third Law, thus stated, uses the words action and reaction to refer to the physical forces operating on two interacting objects. These forces exist simultaneously (equal magnitude, opposite direction), as in the image below.


*** Be forewarned: The writing analogy strays from the simultaneity implicit in Newton’s Third Law. ***

In WriterSpeak (with a little simplification), Newton’s Third Law could be translated as follows: “Every (protagonist) action sparks an opposing (antagonist) reaction.” Conversely, each enemy attack creates some situation to which the hero must respond.

Why? Not necessarily because the antagonist is a bad person (he may not be a person at all), but because he and the hero have clashing goals (e.g., The Fugitive‘s Dr. Richard Kimble vs. Deputy Samuel Gerard).

Dr. Richard Kimble (played by Harrison Ford) professes his innocence and Deputy Samuel Gerard (Tommy Lee Jones) says, “I don’t care.” (But guess what. He cares.)

On a basic level, the central conflict of every novel is founded on this tug-of-war interaction between a hero and his opposition. The antagonist acts (cause). The hero reacts (effect). For every action taken, some change occurs that invites further response. Plot is, by definition, a sequence of events linked by action and reaction—by cause and effect. (More on that here.)

On a large scale, we can see this basic tug-of-war structure across Star Wars episodes 4 to 6. In A New Hope, the rebels destroy the Death Star. (Hero victory!) But then The Empire Strikes Back. (The hero withdraws to lick his wounds.) Finally, in Return of the Jedi, hero Luke not only overcomes the antagonist (Darth Vader), but also rescues him from the dark side. (Permanent victory! The central conflict is resolved.)

Back and forth like lumberjacks moving a two-person saw, the hero and villain push and pull, perpetually digging in deeper. It’s not always as straightforward as hero vs. villain, but the point is, your hero isn’t working in a vacuum (er—unless you’re writing sci-fi). But even if he is in a literal vacuum, it’s not clear sailing to the finish. He’s dodging space debris where there should be a planet, getting caught in a tractor beam, and being diverted into smelly garbage mashers by a pushy princess (all because he’s coming up against that antagonistic force).


Motivated by some personal need, the hero presses forward in pursuit of his goal. That goal is what’s driving him forward. But he must meet with opposition or else the story sags. After all, opposition stems from that all-important ingredient of good fiction, which finds its origin in that action-reaction push and pull: Conflict!

What do you think? What are the forces of antagonism in your own story? Do you enjoy a story more when the antagonist is blatant (as in Star Wars and Silence of the Lambs) or when it’s more subtle (as in The Help or Forrest Gump)? Leave a comment below (and drop your email here) for a chance to win a 2500-word critique or an e-copy of Janice Hardy’s book Understanding Conflict. To enter the “special giveaway” with the option of winning a $25 gift certificate from Better World Books, visit the permalink here and follow the instructions.

Missed the first two? Check them out here: Part 1: How Newton’s First Law mimics character motivation. AND Part 2: How a character’s internal change mirrors Newton’s Second Law.

Cause & Effect in Fiction

Almost everything in a story is the effect to some earlier cause. Indeed, in all of life, this same principle holds true.

You exist. Why? Because your parents…got a visit from the stork. Your eyes are brown. Why? Genetics. Normally you arrive early to work, but today you’re late? Why? Because the alarm didn’t go off because a storm hit last night while you were sleeping and killed the power. mikado-1013877_1280-cause-and-effect4

Your personality may be completely different from that of your parents, but your ingrained traits are, in themselves, the cause for a whole host of other effects. Like the career you choose. The friends you keep. Why you react a certain way in response to some external stimulus. All these things, too, are affected by your life experience. (Human beings are complex.)

Even a glimpse into the universe points to a chain reaction of cause and effect. Light from distant galaxies is red shifted. Why? Because light is composed of waves. Because the wavelength determines the color observed. And because—if the source of light (e.g., star) is moving with respect to the observer—the waves will (seem to) be squished or stretched out depending on whether the star is getting closer or moving farther away. But why is there a red shift? The universe is expanding. Why? The Big Bang set it all in motion.

sky space telescope universe

From these examples, we can recognize a few different elements of fiction that are guided by cause and effect.

(1) Governments, technologies, physical laws, and rules of magic

Just as the physical universe is governed by certain laws, so too whatever world your particular characters happen to inhabit must be governed by consistent laws. If your novel involves magical creatures, don’t change their abilities as the story progresses. If you’ve imagined a futuristic technology, make sure you’ve clearly defined its capabilities, then stick to them. If your story hinges on the mystery of what your magical creatures (or technologies) can do, don’t fret. Just be aware that readers need something logical they can grab onto until the newest revelation occurs.


(2) Personality constraints

Plot is a complex interplay between external events and character decisions (i.e., actions). Perhaps your plot is begging you to take the story in a particular direction… But if that change requires your protagonist (or antagonist) to behave in uncharacteristic ways, you’re better off considering other options.

The bottom line here is that characters must be consistent. If they do change (as we expect), their behavior should shift gradually… and only because the plot has taught them a lesson. In other words, don’t let your protagonist act uncharacteristically confrontational (or whatever) just because it heightens the drama.

(3) External action and consequence

From the smallest fragment of a scene to the broad expanse of character arc and plot, cause and effect permeates good fiction.

The central conflict of every novel, for example, is founded on the tug-of-war interaction between a hero and his opposition. The antagonist acts (cause). The hero reacts (effect). For every action taken, some consequence (i.e., conflict) ensues. Plot is, by its very definition, a sequence of events linked by cause and effect.

Cause and Effect Mind Map. You can think of “Character 1” (teal) as the hero and “Character 2” (red) as the antagonist. Or you can think of them as hero and heroine. Interaction takes place where teal and red meet. Note that the color of the box designates the character to which that particular “property” applies. For example, Character 1’s wound may lead him or her to keep secrets, which in turn may result in Character 2’s misguided action (since they’re acting on wrong beliefs). The purple boxes represent external events that could affect either character. And, yes, this is terribly nerdy, but it was fun to contemplate. (Get a closer look here.)

On a smaller scale, characters are always interacting with the world around them. Although character personalities will differ, their response to any given external stimulus always follows a predictable sequence, as outlined by Swain:

  • Automatic Physiological/Visceral Feeling (e.g., a rush of adrenaline)
  • Reflex/Jerk Reactions (e.g., screaming, jumping in fear, lashing out on instinct)
  • Rational thoughts, speech, and actions

For example, you’re leading a friend through a peaceful forest when all of a sudden the tickling stickiness of a web envelops your face and the creeping crawl of eight tiny legs works its way up your neck. You may not demonstrate each of the reactions in the sequence above. But if you do, they ought to occur in the following order:

First, your heart launches into your throat (physiological reaction). Then, you emit a high-pitched screech as you frantically claw at your neck and face (jerk reaction). Finally, as soon as you’re safely spider-free, you turn to your gawking companion, blush, and sheepishly explain what just happened (rational speech).


Any change in the order will likely come across to readers as being unrealistic. (For example: You turn to your friend. “I just ran into a spider web. Man, I hate spiders. They totally freak me out. In fact, I can feel one crawling up my neck this very instant. Hang on a sec.” Then you shriek and frantically flick the offending arachnid as your heart slams against your ribcage.)

Cause and effect is important enough I’m sure we’ll discuss it again eventually. But for now… What do you think? Is everything in a story the effect to some earlier cause? Are there blatant exceptions to that rule? Join the discussion below for a chance to win a 2500-word critique.