Four Logic Problems that Will Ruin Your Day (and Your Manuscript)

As I’ve mentioned in other posts, there are a number of reasons why I may toss a book aside and never pick it up again. Clichéd characters, dragging first chapters, too much going on…the list, sadly, is long. (For my own personal list of what NOT to do in the opening pages of your story, check out the What Killed It For Me series.)

One of the things that most certainly WOULD kill it for me is when there are problems with the logic. If the author contradicts himself or something happens that totally doesn’t make sense…I don’t have much patience for that, and I don’t think most other readers do, either. Luckily, you don’t see much of this in published books because editors catch those mistakes. But it’s an issue I see quite a bit in manuscripts, and these little problems can slide your baby right out of an editor or agent’s inbox and directly into the circular file. None of us want that.

So I’m excited to welcome Harrison Demchick today to talk about something we’ve never discussed before at Writers Helping Writers: logic problems in manuscripts and how to avoid them.

Have you ever read a scene in a novel, or seen one in a film, that flat-out did not make sense?


Giacomo Spazio @ CC

I’m not talking about flying humans or talking animals or time machines. In their own contexts, there’s nothing illogical about any of these things, or for that matter anything else you can imagine. What I’m talking about are those moments where the protagonist says something he would never say or does something he would never do. Or those revelations that directly contradict already established fact. Or Halloween taking place two weeks after the Fourth of July.

These are logic issues, and if you remember how they made you feel when you spotted them, you know how your readers feel when such problems emerge in your own work. Logic problems remove readers from the world you’ve created. They take from you your narrative authority. They undercut conflict and tension. And if not identified and fixed, they will ruin your manuscript.

So let’s take a look at four different kinds of logic issues, where they come from, why they’re a problem, and how they can be resolved.

Type #1: Rule Violation

What it is: An apparent contradiction or inconsistency relative to the established rules of your world. 

Some might suggest that there are no rules in fiction, but that, of course, isn’t true at all. When it comes to establishing the world of your novel, there are two sets of rules: the rules readers bring to the story and the rules you bring to the story.

What readers bring to the story is common sense. That’s why you don’t have to explain concepts like restaurants, Sundays, and love and hate, and also why you don’t need to tell readers that someone who falls into the Grand Canyon is probably going to die. You, on the other hand, provide basic context—the particular rules and concepts that differentiate (or don’t) your world from the real one. If, in fact, it is not lethal in your world to fall into the Grand Canyon, or if the bottom of the Grand Canyon is an enormous trampoline, then you need to establish this.

Common sense and basic context comprise the rules of your novel, and when those rules are ignored or changed without explanation—for example, a human having an intellectual debate on Tolstoy with a box turtle in a world previously depicted as ordinary Victorian-era England—then we have problems.

Why it’s a problem: In a world without rules, nothing has meaning. Imagine your protagonist dangling off the edge of the aforementioned Grand Canyon. The tension in such a scene emerges from readers’ understanding that an ordinary man who falls into the Grand Canyon will die. But if there are no rules—if rules are added or changed or removed on a whim—there can be no tension. Maybe the character will die, or maybe he’ll bounce, or maybe he’ll fly away. Readers don’t know. And most problematically, very soon, they won’t care.

How to resolve it: Establish the rules early in your manuscript, ideally before the inciting incident. This is more difficult in some genres than others—it’s hardest for fantasy and science-fiction, which require a lot of basic context—but generally speaking, you want to establish the status quo before you change it. And ideally, this is done through showing rather than telling. Convey from the beginning a world in which turtles can talk with humans and that Tolstoy debate will read just fine.

Type #2: Continuity Violation

What it is: A contradiction or inconsistency relative to anything that has happened in your manuscript up to any given point.

This one is pretty simple. Everything that happens in your manuscript—not just every event, but every detail established in every sentence—is part of your continuity, and when you contradict that, you violate continuity. A character established as twenty-two can’t be twenty-five the next day. She can’t live in a trailer park on page 12 and a studio apartment in Greenwich Village on page 60. She can’t be lactose intolerant, then eat a giant bowl of ice cream without consequence.

Why it’s a problem: When readers invest their time and energy in your manuscript, you essentially promise them that you’re the world’s leading authority on the story you’re telling. Continuity violations break that promise. For readers, this is intensely frustrating, because if you seem not to know what you’re talking about, their time becomes a wasted investment. When you lose your authority, you lose your readers.

How to resolve it: First of all, be vigilant. Most continuity errors are simply mistakes. You forget what you wrote before, and thus accidentally contradict it. We all do it, and it’s not a big deal—just read carefully, and have someone else do the same if you know continuity to be a problem.

But you might also consider foregrounding. Foregrounding is addressing the continuity violation head-on, in the process making it part of the story. If something doesn’t make sense, but you or your characters acknowledge that it doesn’t make sense, readers will stick with you and accept it as either an intentional detail or something that will be explained later.

Type #3: Inconsistent Chronology

What it is: Inconsistency in the established passage of time in your manuscript, or lack of clarity and logic in when events occur relative to other events.

We know, as part of common sense, that night follows day and that there are five days in a typical school week, but this doesn’t mean that time passes automatically and logically in your manuscript. I’ve edited three different young adult novels in which school weeks lasted seven days or more, all because the authors referred to “the next day” and “the next day” without keeping track of how many next days had passed. I edited another novel in which, due to overuse of “several months later,” winter lasted for more than a year.

Why it’s a problem: Continuity will frustrate you, but chronology will kill you. You can’t make your climax the Thanksgiving Social if only two weeks have passed from the start of the school year. You can’t have two characters start and end a journey at the same place and same time when one’s adventure lasted three days and the other’s a week. Inconsistent chronology can result in impossible plot points, and these issues are very difficult to unravel.

How to resolve it: If chronology is a concern, timelines can make a huge difference. Create a separate document keeping track of the passage of time in your manuscript. Know for yourself exactly when anything happens relative to anything else. If you write it down and make it a point of focus, you should be able to keep such problems under control.

(Note from Becca: For cool possibilities in timeline software, check out Aeon Timeline, or download Timeline for Microsoft Office or TikiToki for Macs.)

Type #4: Rationalization

What it is: Pushing your characters or plot in the direction you want them to go even when other logic issues make this unlikely or impossible.

The killer strikes in broad daylight even though she’s previously only worked at night, and the only reason is that we’re nearing the end of the novel and the author wants her to be caught. A caring uncle abandons his niece and her friends because the author wants the protagonists to face the villain alone. These important moments are guided not by the needs of the story, but rather the needs of the author, who will spend paragraph after paragraph trying to rationalize her decision.

Why it’s a problem: I sometimes call this 2 + 2 = 5. It doesn’t matter how much explanation an author provides: two plus two will always come out to four, not five. Readers know that, and at heart, authors know that too—that’s why they’re working so hard to convince readers otherwise. Problems with rationalization make fundamental plot points impossible to believe.

How to resolve it: You can’t fix this one with foregrounding, because the explanation is often the problem. Instead, remember that you control both sides of the equation. If you can’t get two and two to equal five, change one of the twos to a three. Find another way to get where you want to go. Instead of forcing something that will never make sense, create something that will.

While logic alone will never create a great manuscript, you can’t create a great manuscript without it. Don’t give your readers a reason to put your book away. Mind your logic.


portraitcolor smallHarrison Demchick came up in the world of small press publishing, working along the way on more than fifty published novels and memoirs, several of which have been optioned for film. An expert in manuscripts as diverse as young adult, science-fiction, fantasy, mystery, literary fiction, women’s fiction, memoir, and everything in-between, Harrison is known for quite possibly the most detailed and informative editorial letters in the industry—if not the entire universe.

Harrison is also an award-winning, twice-optioned screenwriter, and the author of literary horror novel The Listeners (Bancroft Press, 2012). He’s currently accepting new clients in fiction and memoir at Ambitious Enterprises.


Angela is over at Writers In The Storm, talking about Gifts That Matter: The Most Important Thing A Writer Can Give Themselves This Christmas, so please stop in and say hello!




Becca Puglisi is an international speaker, writing coach, and bestselling author of The Emotion Thesaurus and its sequels. Her books are available in five languages, are sourced by US universities, and are used by novelists, screenwriters, editors, and psychologists around the world. She is passionate about learning and sharing her knowledge with others through her Writers Helping Writers blog and via One Stop For Writers—a powerhouse online library created to help writers elevate their storytelling. You can find Becca online at both of these spots, as well as on Facebook and Twitter.
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23 Responses to Four Logic Problems that Will Ruin Your Day (and Your Manuscript)

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  5. A timely post! I am working on the logic of my fantasy series right now. I’m in the editing process and in changing things have created a cascade effect of potential logic issues.

    Also, based on your tip, I just purchased the Aeon Timeline software -goodbye Excel timeline! I’m excited to try it out.

    • Harrison Demchick says:

      I’m very glad Becca added that tip too! I always want to recommend *something*, but I do most of my organization through Word and thus never actually try programs like Aeon Timeline. I’d love to know if it helps–that way, I can recommend it when I speak on logic at writing conferences.

      I was at one of those conferences–actually, a sci-fi/fantasy convention called Chessiecon–just a few weeks back, speaking on logic in genre fiction. With fantasy, Jennifer, it can be tricky, as every fantasy world is going to have its own rules, but the fact that you’re already thinking about logic and addressing the problems means that you’re certainly on the right track.

  6. :Donna Marie says:

    This is great stuff, for sure, and to me is one of the biggest reasons plotting/outlining/recording important details, is critical in novel-writing 🙂 Thanks for this!

    • Harrison Demchick says:

      Of course, Donna! But naturally, putting together an outline doesn’t take care of everything. In fact, I’ve never seen an outline that survived the writing process, because new ideas and unforeseen problems inevitably get in the way. That said, having some kind of plan certainly makes it easier to keep your story details straight.

  7. Great post. Now if I can remember it all!

    • Harrison Demchick says:

      The *real* trick, Carol, is internalizing it, to the point where you’re looking for these things on instinct. But as far as memorizing, this post isn’t going anywhere! (At least as far as I know.) If it emerges as something you can return to now and then as you work–if it helps–then I’ve done my job.

  8. I love this post. Honestly, when things don’t make sense in a story, it drives me bonkers. It’s one of the most obvious problems, I think, to readers, but it’s so hard for us to see in our own work. Thanks for sharing, Harrison!

    • Harrison Demchick says:

      Thank you for hosting! Logic is one of my favorite subjects to discuss with writers. We love to think of fiction as a realm in which anything can happen–and it is–but sometimes that blinds us to the importance of logic in crafting a great story.

  9. Logic is one of my biggest bugaboos when critiquing, so I am thrilled to see you tackle it here – great post! Thanks for sharing your insight with us. 🙂

  10. Martha Ramirez says:

    This is all so true! Thank you so much for the great tips!

  11. A lot to keep an eye on for sure!!

    • Harrison Demchick says:

      It is, Traci! But that’s a lot of what writing a novel is to begin with. There are so many moving parts, and they all impact upon one another in ways we cannot always predict. The more you know and understand, the easier it becomes to craft your story into something great. (Which is not to say that it’s ever actually easy!)

  12. Kessie says:

    Ugh, yes, logic problems! Nothing makes me gnash my teeth like logic problems in a story. A corollary is a smart character being handed the idiot ball–they do stupid stuff to advance the plot, usually in act 3, right before the climax.

    I have beta readers who kick my butt over logic problems in my own work. Often the problems require extensive rewriting to fix, too.

    • Harrison Demchick says:

      Exactly, Kessie. Characters do dumb things when they’re serving the story rather than themselves. And that trap is so, *so* easy to fall into. I was doing it myself with my writer’s group just this past Sunday. My characters weren’t behaving stupidly, but events were happening because I wanted them to happen, not because it fit the progression of the story. I spent the next two days trying to work out the logic problems I was caught up in–which I think I have. But now I need to resolve them in the manuscript, and *that* is going to take some rewriting.

      And this just goes to show you how insidious logic issues can be, even when you’re a developmental editor who knows all about them and spots them easily in other writers’ manuscripts. That’s why it’s so important to keep these things in mind.

      • Kessie says:

        There’s one in the first Twilight book that sets my teeth on edge. Bella was pretty savvy for the whole book, and when she was in danger, she did what the vampires advised. UNTIL the last part, when the vamps are doing everything to keep her safe, and she RUNS AWAY to a secluded location to meet the bad guy. It was so boneheadedly dumb, and so against the way she had acted throughout the rest of the book!

        • Harrison Demchick says:

          Great example. The author needed it to happen, so it happened. And for every one example that makes it to print, there are countless others edited away during the revision process. When you’re editing early drafts of manuscripts all day, as I do, you see these things all the time.

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