What makes a good plot twist?

I don’t just write thrillers. I am also a voracious reader of them. There is a lot to love about the genre—fast-paced stories, larger-than-life characters, sky-high stakes. But one of my favorite things about a good thriller is a perfectly executed twist.

As thriller fans, I’m sure you know what I’m talking about—the shocking reveal, the abrupt reversal, the twist that you never saw coming, but that you should have.

In today’s blog, I thought it might be interesting to dig into this subject and try to dissect what makes a good twist work.

What are some elements that separate a good twist—one that brings a huge smile to your face—from a bad one that makes you roll your eyes? I would offer the following rules:

• A good twist needs to be fair to the reader. The truth is right there in the pages all along, if only the reader is alert enough to see it.
• A good twist is true to the characters. A very common twist is that a good guy turns out to be a bad guy or vice versa. This twist can be very effective, but only if the character was believably “faking” his or her prior role and if he or she was sufficiently motivated to do so.
• A good twist enhances the story, but isn’t the point of the story. Some stories are like jokes, in that they exist solely to support the punchline. This can work on rare occasions—The Usual Suspects and The Sixth Sense are two examples that come to mind—but usually a story told purely as the setup for a twist will not be a satisfying story in and of itself.

Digging even deeper than these general rules, how, exactly, does a twist work? I consider myself to be intelligent. You’re probably pretty smart, too (most book readers are, in my experience). So how is it that these twists fool us, again and again? How are these writers outsmarting us?

Here, I’m going to take off my reader hat, put on my writer hat, and give you a glimpse behind the curtain. Because, while some twists occur naturally in the writing, surprising the writer as much as the reader, most twists are deliberately constructed according to a method that is similar to methods magicians use while performing magic tricks.

The secret is that twists exploit assumptions. All people—even highly intelligent ones—supplement their actual observations with assumptions about how the world works. If you look at a person from behind and the person has a diminutive frame and long hair, you will probably think the person is a woman. This conclusion is based on your actual observation—body type, long hair—and an assumption—most people with small frames and long hair are female. Now the person turns around and you see it’s a man. You experience a moment of surprise as your brain readjusts.

Take that simple example and use it in the context of a thriller. You observe a well-organized group of foreign men with assault rifles, explosives, and other weapons infiltrate and hold hostage an office building in LA. You probably think they are terrorists. But this conclusion is based on assumptions. When it turns out that these men are actually thieves trying to steal bearer bonds, you have the awesome twist in the third act of Die Hard. (Sorry for the spoiler, but hey, the movie is almost 30 years old.)

I’ve tried to use twists in my own books. Some of them have been more effective than others, but overall I think I’ve done a good job. (I often see reviews praising the surprising twists and turns in the stories, which I take as a sign I’m doing something right.) And because I enjoy reading a good plot twist so much, I’m always eager to learn more about how and why they work.

Do you have ideas about what makes a good twist? If so, please share your thoughts in the Comments section below.