Nothing kills my trust in a book faster than a coincidence that shows up exactly when the writer needed it. The door happens to be unlocked, the hero happens to overhear the one conversation that matters, and I’m out.
What is a plot device?
Coincidence is only one plot device. Objects, characters, pieces of information, prophecies and twists move a plot too, every narrative needs them, and each one either justifies its place or cheats your reader. For more, see why strong verbs beat adverbs and short story techniques.
The question isn’t whether you need plot devices, you do.Share on X
I’ve ghostwritten 54+ books and written dozens of novels of my own. The most common structural problems I see in manuscripts, both mine and my clients’, come down to plot devices that seemed clever during drafting but don’t hold up under scrutiny. The object that drives the quest but could be swapped for any other object. The rescue that arrives from nowhere. The coincidence that makes the story possible. The twist that invalidates everything the reader invested in.
These aren’t minor craft issues. A bad plot device collapses an otherwise strong novel, and I’ve watched it happen to books that deserved better. A good one lifts a simple story into something readers still talk about years later.
Bad plot devices are billed to the wrong person. The writer saves a week by dropping in a convenient rescue, and the reader pays with the hours they spent caring about a danger that turned out to be fake. I think most of these shortcuts come from impatience, and I’d rather see a writer tear up three chapters than give a reader a cheat they’ll spot.
Watch: On Setup, Suspense, and Certainty: Chekhov's Gun Explained, Fandor
What Makes a Plot Device Work?
A plot device works when it’s so woven into your story that removing it would change everything. Not just the plot. The characters, the theme, the emotional experience. If you can swap your device for a different one and the story stays the same, the device isn’t doing enough. The Awful Writing Handbook calls this the Swap Test: replace your central object, event, or mechanism with something else of similar function. If nothing changes, you’ve written a placeholder. If the substitution breaks the story, you’ve written something specific enough to matter.
Three qualities separate working plot devices from broken ones:
- Connection to character psychology. The device should affect different characters differently. It should tempt, test, reveal, or transform the people who interact with it. The One Ring in Tolkien’s work tempts Boromir with visions of saving Gondor, tempts Galadriel with becoming a terrible queen, tempts Sam with gardens. Same object, different temptations. That’s psychological depth. A device that affects everyone the same way is furniture.
- Connection to theme. The device should embody, challenge, or explore your story’s central questions. The Ark of the Covenant in Raiders of the Lost Ark is a powerful object that represents divine judgment. It rewards faith and punishes hubris. When it finally opens, the spectacle delivers on that meaning. A device disconnected from your theme is a prop.
- Rules that create story possibilities. The device should have specific capabilities, limitations, and costs. Rules create tension because characters must work within constraints. Generic power (“it can do anything”) closes possibilities instead of opening them. The more specific your device’s rules, the more interesting the story problems it generates.
Which Plot Devices Wreck Stories?
Some plot devices show up in manuscripts so often that they’ve picked up names. None of them is automatically fatal, and some writers have used every one of them brilliantly. Most don’t. I tell writers to hunt for these patterns in their own drafts before a reader finds them, because a reader who spots one stops trusting you and never bothers to say why.
The Interchangeable MacGuffin
Alfred Hitchcock popularized the term MacGuffin to describe the thing characters chase that audiences don’t really care about. He used MacGuffins intentionally in thrillers where the chase mattered more than the prize. The problem comes when fantasy and science fiction writers create quest objects that are just “powerful” without any psychological weight, thematic connection, or clear rules.
Coincidence that gets a hero into trouble is fine. Coincidence that gets him out isn't.
The Tesseract in early MCU films is a textbook example.
It’s a source of unlimited power. Loki wants it. HYDRA wants it. Everyone wants it. But you could replace it with any other powerful object and nothing in those stories changes. Compare that to the One Ring. That corrupts everyone who touches it in ways specific to their deepest desires. The Ring is irreplaceable. The Tesseract is interchangeable.
If your quest object could be swapped for any other magical item and nothing would change, it’s still a placeholder you forgot to replace.
Deus Ex Machina
The term comes from ancient Greek theater, where a crane literally lowered an actor playing a god onto stage to resolve impossible situations. In fiction, it’s any rescue or resolution that arrives from outside the story’s established logic.
Writers create deus ex machina when they’ve written themselves into corners. The heroes face unbeatable odds because unbeatable odds feel dramatic. Then the writer realizes the odds are unbeatable and reaches for a miracle instead of restructuring the story.
The eagles in Peter Jackson’s Hobbit films are the famous example.
Dwarves trapped in trees, no escape, then giant eagles appear and carry them to safety. The pattern repeats. Audiences learn to stop worrying because eagles might show up anytime. That’s the damage: deus ex machina doesn’t just cheapen the rescue scene. It retroactively diminishes every danger that came before it.
The fix is structural, and it’s work. Set up your rescues early. Let characters save themselves with skills and resources you already gave them. Let mistakes cost something. If you’ve written yourself into a corner, go back and rebuild the corner. A miracle is easier than a rewrite. That’s exactly why so many books have one.
Coincidence-Driven Plot
The hero needs a clue and just happens to overhear the exact conversation that hands it over. Readers roll their eyes every time. The villain needs to escape and, what do you know, somebody left the door unlocked. The lovers bump into each other at the one coffee shop in a city of millions.
Real life contains coincidences. Fiction should contain fewer of them. One coincidence to set the plot in motion is acceptable (many great novels start with one). Coincidence to resolve the plot is almost always a cheat. When coincidence replaces causation, readers stop believing in your story and start seeing your hand moving pieces around a board.
Gillian Flynn’s Gone Girl shows the fix. The story seems full of coincidences until the reader discovers that Amy planned everything. What looked like chance was design. That’s the gold standard: apparent coincidence revealed as character action.
The Tension-Killing Prophecy
A wise woman declares that the chosen one will defeat the Dark Lord. The young farmboy has the birthmark. And just like that, the story has told us how it ends. Prophecy in fantasy should create tension. It usually destroys it. When ancient texts guarantee the outcome, the reader knows the hero will win. Not suspects. Knows. The prophecy said so. Story tension requires uncertainty about outcomes. Prophecy removes uncertainty. I can’t abide the bolted-on prophecy, and I blame the genre’s habits as much as the writers. A thousand fantasy novels taught new authors that a chosen one needs a prophecy, so they add one without asking what it costs. It costs them every ounce of suspense they had.
Oedipus Rex shows how prophecy can work: the characters’ attempts to avoid the prophecy create the conditions for its fulfillment.
The prophecy traps them through their own actions. That’s ironic tragedy, and it’s dramatically powerful. A prophecy that simply says “you’ll win” and then the hero wins is a spoiler the author put in on purpose.
“It Was All a Dream”
The reader finishes the last page. Everything they experienced, the adventures, the relationships, the emotional arc, none of it happened. The protagonist wakes up. It was all a dream.
This tears up the contract between writer and reader. Your reader gave you their time and their feelings, and the dream ending tells them none of it counted. The stakes were make-believe even by the standards of fiction, and readers don’t forgive it.
Deaths can break that contract too. Quentin Tarantino’s violence is a little too grotesque for me, and his characters don’t die right. In Django Unchained, Dr. King Schultz, the former dentist, just dies. I’ve written before that when you build a character up, he needs a good death. That wasn’t one. Kill Bill was okay. It makes great clips, but it doesn’t hold up on rewatch.
Christopher Nolan’s Inception shows how dream-questioning can work: the ambiguity between dream and reality is the point of the entire film. Whether Cobb is dreaming or awake, his emotional arc matters. That’s the difference between using dreams as theme and using dreams as a cheat.
The Idiot Plot
Roger Ebert coined this term for stories that only work because every character in them acts like an idiot. One sensible decision, one obvious precaution, one moment of basic competence would resolve everything. But that would end the story, so everyone becomes stupid on schedule.
The fix isn’t making characters smarter in ways that eliminate conflict.
The fix is creating situations where smart characters face difficult choices with no clean answers. Real conflict emerges from characters with incompatible goals, limited information, and no good options. That’s harder to write than making people stupid. It’s also the difference between a frustrating story and a gripping one.
The idiot plot insults readers more directly than any other device on this list. A smart reader watching a supposedly smart character do something stupid feels talked down to, and I think writers only get away with it because readers are polite enough to keep turning pages. That’s a hell of a way to treat the people who bought your book.
Plot Devices That Work Across Genres
Some devices appear in every genre because they solve fundamental narrative problems. These are the reliable tools.
- Chekhov’s Gun. Anton Chekhov’s principle: if you show a rifle on the wall in act one, it needs to fire by act three. Everything you introduce should pay off. Everything that pays off should be introduced. Shaun of the Dead uses this brilliantly, with early throwaway mentions becoming decisive plot elements later. The device works because it rewards attentive readers and creates a sense of inevitability in the story’s logic.
- The Red Herring. A clue, character, or event designed to mislead. Essential in mysteries but useful in any genre where you want readers guessing. A good red herring must have a plausible innocent explanation when the truth is revealed. If the red herring only works because you withheld information, you’ve cheated.
- The Ticking Clock. A deadline that creates urgency. The bomb will explode in twenty minutes. The ship launches at dawn. The verdict comes down Friday. Ticking clocks work because they compress decision-making and force characters to act under pressure. That reveals who they really are.
- The Reversal. A moment when the reader’s understanding of the story flips. The ally was the villain. The victory was a trap. The safe place is the most dangerous location of all. Reversals work when they recontextualize everything that came before. They fail when they contradict established facts just for shock value.
- The Dilemma. A choice between two options where both have real costs. The character can save the city or save the person they love, but not both. Dilemmas are among the most powerful plot devices because they force characters to reveal their values through action, not dialogue.
How do you test whether a plot device works?
Before your manuscript goes to beta readers, run these diagnostics from the AI-Enhanced Awful Writing Handbook:
- The Swap Test. Replace your central plot device with a different one of similar function. Does anything in the story change? If not, your device needs more specificity.
- The Setup Check. For every rescue, reveal, or resolution in your climax, trace its setup. Where was this element introduced earlier? If it wasn’t, you haven’t justified the payoff.
- The Coincidence Count. Count the coincidences required for your resolution to work. Timely arrivals. Lucky discoveries. Perfect timing. One coincidence is acceptable. Multiple coincidences compound into deus ex machina.
- The Consequence Audit. What do characters lose that they never get back? If no permanent consequences occur in your climax, your stakes weren’t real.
- The Reader Cheat Check. Imagine a reader invested in the conflict reaching your resolution. Would they feel satisfied or cheated? Listen to the answer.
For detailed analysis of 40+ plot device failures with movie and book examples, fix strategies, and AI diagnostic prompts, see the AI-Enhanced Awful Writing Handbook. For red herring construction and clue-planting techniques, the AI-Enhanced Mystery Writer’s Handbook covers fair-play principles in depth.
Some writers flinch at the AI part of that. I think “don’t use AI” is the most wrong-headed writing advice going around right now. Used as an assistant for diagnostics like these, and never to write the book, it can probably get an author’s books out four or five times faster, and the writers who refuse it are going to be competing with the ones who didn’t.
Every book leans on a few plot devices, and I’ve got no quarrel with that. My quarrel is with the lazy ones, because each of them is a writer deciding that their own convenience matters more than the reader’s trust. If a reader can see your hand moving the pieces, you’ve lost them, and they won’t be back for your next book either.
Frequently Asked Questions
Writing It Yourself? Keep Going.
If you want a professional in your corner while you write, my writing coaching works one on one without taking the pen out of your hand. The Plot Handbook takes this topic deeper.
