Every story has rules. Every setting has laws. Often unknowingly, we shape these rules as we write. With every sentence, we solidify the reality of a story. With every sentence, we're making a promise to the reader. How often have you become disillusioned with a story because the basic laws of the setting are conveniently bent in order to ensure a tidy conclusion? You're left saying, “But...but the author said that X would happen if Y ever happened.” When you break the rules of your own story to achieve an effect, you're cheating the reader. Don't fool yourself, the reader will always know when you're cheating her, and she won't be happy with you.
What is Internal Consistency?
At heart, it's a pretty simple concept. When you've built up a “truth” about your setting, don't go bending that truth or throwing it out, just because it's getting in the way of that slam-bang finale for chapter six. If you've created a universe where it's physically impossible to exceed the speed of light, it's bad form to suddenly have a simple way to do so, just because you have to get the characters to Alpha Centauri right away. That's cheating.
If you've written a story that states that anyone who drinks White Venziri poison will die of convulsions within three minutes, don't have the main character hold out for several hours while his trusty sidekick rides off to find the antidote. The main characters get to be special, but if nothing affects them the way it would affect a normal person, what's the point of even introducing the poison in the story?
In the same way, if your character has a heart condition, and has to be very careful, or she'll expire from a sudden heart attack, you'd better not have her running at full tilt for the final two hundred pages of the book. It doesn't make sense, unless all her problems were psychosomatic. If your character is terrified of heights, having him run up a greased rope and fight on the crest of a rooftop with three ninjas is probably going to look pretty foolish. Make a promise, then keep it.
Another big issue of internal consistency is that of scale. Don't fall prey to the urge to make “everything louder than everything else”. What I mean by this is, don't go overboard and make everything so extreme and gigantic that it doesn't make any sense. There's no need for million man armies in a low-tech setting. There's no need for your character to slay six hundred men in the course of the book. Trust your readers. Make the events dramatic by describing them beautifully. Don't make your story into a Slam! Bang! Crash! action movie, just because you feel the need to keep increasing the stakes. There are a lot of ways to do that, and simply pumping up the scale to an impossible level is probably the least imaginative. When you overdo anything, you lose your readers. Regardless of how strange, wonderful, or grotesque an event might be, it will become reduced to the point of the absurd if it happens too often. If your villain yanks people's ribcages out and wears them for a hat, that will eventually just make the readers laugh.
In subtler circumstances, you want to make sure that your characters remain true to their personalities unless there's a strong motivation for them to change. They shouldn't “change their stripes” easily. Having the old, greedy merchant suddenly grow a heart of gold because he thinks your main character is neat is not good structure. Having the inveterate coward suddenly risk life and limb for some noble purpose stretches credibility. If these things are to happen, you absolutely have to set them up over the course of time. The whole point of stories is for characters to learn and change, but this has to be earned. If the greedy become generous, if the cowardly become brave, you have to show the process by which these things occurred.
Finally, remember that some rules have to be examined for their merit. Don't make stupid rules just to get your plot off the ground. If the two leads in a romantic book can't be together, make the reason for this plausible and interesting. Maybe their countries are at war. Maybe events in the book sweep them apart for many years. Maybe they hate each other at the beginning. Don't let yourself cheap out on the plot by stating, “Jane, because she was the last of the Cardenelli Singing Wizards, could never marry Bart. Bart, who was a warrior of Fistelbars, would cause Jane's nose to fall off if he ever touched her.” That's stupid. Sorry, but it is. Magic is probably the most dangerous plot point you can possibly use, because the temptation to use it will be so strong. Any magic should be backed up by logic based upon the more prosaic laws of your setting. Few, if any plot points should be based directly upon the availability of magic alone.
How can I be internally consistent?
First: don't ever “cheap out” on the ending. If the easy way to conclude an event, or the story as a whole, is to bend the rules a little, don't do it. You'll be especially tempted to do this when there's a magical or super-technical element to the story. Don't invent a magic spell or gizmo that will let the characters off the hook. It's much better for them to save themselves, or even be doomed, than to do this.
Second: always have characters be true to themselves. If a character is a grouchy jerk who always drives everyone away, don't have him suddenly reform himself. If he's going to find some way to be nice or charismatic, that'll have to be a part of the journey, not an overnight event. Remember that the outward struggles in a story are just the tip of the iceberg. The greater struggles are often with our own difficult natures. Characters should have big, seemingly intractable problems, and it should take all their efforts to solve them. If their personalities are badly suited to the cause, all the better. That way, they'll be fighting themselves the whole way. If the coward finally makes good and acts bravely, that's a bigger payoff if the character has been allowed to struggle with his problem all through the story.
Third: consider your setting. Think about the average person in your setting. Where do they get food? What do they do for a living? Are they free to move up the social hierarchy, or are they held to the caste they were born in? It's important to remember that, in most settings, there has to be a great number of “regular folks”, like farmers and laborers, for every “special person”. Remember that big things cost big money. Remember that whatever great event your character is involved in, there will probably be a lot of normal folks who will feel the aftermath. Bringing these truths into a story only improves a reader's perception of reality.
Fourth: consider your actions. Do research. If you can, see if the things you're describing in a story are humanly possible. If you can model whatever behavior a character is doing on a known activity, try to make sure that your character isn't far beyond the realm of mortal ability. Also, try to work out the logical consequences of each big event in your story. If it would really make a group of people angry, let that be part of the story. If the aftermath of the titanic battle would stop trading between countries, maybe there would be shortages or even famine. Never forget to explore “the rest of the story”. If characters are forced to clean up their own messes, or at least to confront them, you'll have a much stronger, richer story as a result.
Internal consistency is often a matter of common sense, but, as with all other concerns, it's best to let a few people help you sort things out. Maybe one of your readers will have knowledge you don't, and can suggest a change that will improve the story. Remember that if a story doesn't seem real, no amount of pyrotechnics will impress a reader. You have to earn their trust by giving them the most well-thought-out story you can.
Next time: Content