10 Kinds of Plot Twists

1. The Dream Twist.
   It is the worst and most annoying type of plot twist when the story you have emotionally invested in turns out to have been just a dream. It usually does not please the reader. The only way to save this over-used plot twist from total disaster is to ensure that the events in the dream world has parallel events and emotional consequences in the real world surrounding it. If the adventures in the dream world substantially changes the course of life for the protagonist in the real world, the story can be satisfying. If it was just a dream and nothing changes in the real world, it would be a let down. That means that the dream sequence should not end in a saved-by-the-bell wake-up. If the protagonist is about to die in the dream world and woke up to find that everything was okay, the story is not okay.
2. The Butler Did It Twist.
   The staple of Agatha Christie mysteries, the final twist is that the person you were looking for (the murderer, usually) was someone totally unexpected. The most often mentioned gripe with this twist is that some key information is withheld from the reader until the very end. How was I to know that the nurse was the murderer when it was hidden until the last page that she was secretly a distant relative of the victim with potential to inherit a huge fortune? In order for this plot twist to work, the reader must have access to as much information as possible without making the conclusion too obvious. Also there should be some foreshadowing leading up to the twist.
3. The Upper Hand Twist.
   Someone plans a heist. Someone plans a double cross. Someone predicted the double cross and had secretly taken measures to counter it. When all is revealed, someone had the upper hand. The upper hand twist is the staple of bank robbery and jewel capers. If done well, it rarely fails to entertain. A variation of this twist is when the double crosser switches sides and feeds information to the enemy, but later turns out to have been a mole who planted misleading information on purpose to distract the enemy. Mostly used in crime stories, but also seen in political thrillers and courtroom dramas. It only works if the initial double cross was unexpected for the reader.
4. The Secret Good Guy Twist.
   Hitchcock seemed to have loved this. One of the bad guys is too charming to be true and the heroin falls for him though she is well aware that he is dangerous material. And then, at the critical moment, he reveals himself to have been a secret agent for the good guys. It works best if the reveal is saved for the very end, or if the secret good guy reveals himself to the wrong person, making it a double twist. The premise is often too good to be true. The way to get this to work is to make the secret good guy an increasingly suspicion-inducing character as the story progresses. He must lie a lot, and his lies are exposed one by one, making him progressively less trustworthy. But he keeps patching up his story with new lies which nobody but the heroin (or equivalent) buys. The reader (or the audience) should be screaming “Don’t trust him!” long before the reveal. The best example is Alfred Hitchcock’s Charade.
5. Identity Twist.
   “Luke, I am your father.” Someone you thought was one thing turns out to be something else entirely. Works best when the first characterization is well developed, and the reveal is related to the objective of the story or the motivation of the main character. Darth Vader was perfectly characterized as a murderous villain. Luke was motivated (at least in part) by his desire to avenge his father. When the object of his vengeance turns out to be his father, it flips his motivation and adds a new conflict to the story. Street investigation police stories often employ this device. Old fashioned spy novels sometimes employ this also. This twist would fall flat if the secret identity was not directly related to the motivation of the main character.
6. Hallucination Twist.
   An unreliable narrator who is not really sure what is real and what is his imagination tells a strange and confusing story. It is later revealed that one part of the narrative was a figment of his imagination. Most often, the imagined thing is a character in the story. In this case, one of the characters does not actually exist. The imagined element could also be a series of events, or the inciting incident. The inciting incident that set the main character on his journey did not actually happen, or he was mislead on his journey by a series of hallucinations. This twist works best when the instability of the narrator is amply foreshadowed, but not really exposed until the reveal. You find this plot twist often in the so-called “rubber reality” movies.
7. The Liar Twist.
   An obsession of Orson Welles. You hear a series of accounts from different perspectives of the same event, and eventually the audience pieces together a story, until a contradiction surfaces. Somebody is not telling the truth. The reveal identifies the liar. This works best when the audience has invested enough effort into constructing a story from the various accounts. It is difficult for the audience to identify the liar because his account is one of the key building blocks of the narrative they have come to believe in. However, the reveal is not satisfying if the liar is too far out in left field. There should be enough foreshadowing to make it plausible, but not enough to make it too obvious.
8. Not Dead Twist.
   Someone whom you thought dead was actually alive. This twist cannot work unless the story preceding the twist hinged on the fact of the death. For example, someone is said to have died of illness, but the story does not fit and murder is suspected. The story follows the investigation until it is revealed that the victim was not actually dead. You might feel that this story twist has been over-used. It would take a clever writer to pull this off without making it seem cheap. It works better when a lot of emotional investment is infused in investigating why and how the supposedly deceased died. (A variation is the Dead Twist, in which one of the characters, such as the narrator, previously believed to be alive, turns out to have been a ghost.)
9. The Same Person Twist.
   The most typical examples may be the movies Vertigo and Body Double,  in which characters whom you originally thought were two different people turned out to be the same person. But it can be combined with elements of the Hallucination Twist or the Identity Twist to enhance the confusion, particularly when an unstable character does not really know how many people he really is. It works best when there is a lot of emotional investment infused on finding (or finding out about) one of the (supposedly) two characters. (A clever variation on this is the Two Persons Twist, in which someone, previously thought to be one person, turns out to have been two separate people.)
10. The Stage Twist.
    The story you thought was taking place on a strange alien planet was actually taking place on Earth, or a story you thought was set in medieval times was actually taking place in the present. If done well, this twist can be shocking, like the ending of the original Planet of the Apes movie with Charlston Heston. If done wrong, it will be a let down like a poorly done Dream Twist. This twist has more failed examples than successes. The reason that it is so difficult to pull off is that it needs to be the answer to the central quest of the story. Either the protagonist is vindicated or all hope is lost depending on this final reveal.

A writer does not always plan a plot twist. Often, a story takes a wild turn and a plot twist jumps out at the author. In which case, you have to go back to the beginning and retrofit the foreshadows in the second draft. Whatever type of plot twist you install, somebody has already done it better, but more usefully, somebody has done it worse. A writer should look for examples of the same kind of plot twist where somebody screwed up and ruined it. Then you can improve on the failure and create a better plot twist. If you are the type of writer who plots your stories, a little research can yield some useful information. Even though plot twists in novels are not so heavily researched, information on the plot twists in movie scripts are all over the place. There are plenty of examples out there that can help you fine tune your story. The rule of thumb is, a plot twist works best when a lot of emotional investment is made by the time it happens. The twist should confound the emotional investment.