A doppelganger is a “ghostly counterpart of a living person, a double, or an alter ego.” If a person looks in the mirror, and the face in the mirror does something different than the person making the reflection, or if there’s an evil twin of you running around and doing bad things you couldn’t possibly have done (alibi), then that’s a doppelganger.
I’ve been trying to think of a word to describe something, and the best I’ve come up with so far is “false doppelganger.” If you know of the actual term for it, let me know.
This shows up mostly in beginners’ writing; more professional writers seem to know how to cover this enough so either it’s not apparent or it works as a plot point.
Let’s say you have a story in which the main character falls in love with someone who does something unacceptable–it’s bad, it’s evil, it’s laughable–and then gets killed off. The main character then falls in love with someone else, who essentially is the same as the first person, but promises never to do that unacceptable thing.
I’m calling that a false doppelganger. The second person is a double of the first, but is used only to help the main character avoid dealing with an issue. The better choice would be for the writer to not kill off the first love interest but to keep the same love interest throughout, and force the main character to deal with the unacceptable action.
Another example. Let’s say you have a story in which the main character’s social group is doing something unacceptable, and the main character leaves. During the course of their journeys, they find another society that is doing the same unacceptable thing, only worse. The main character stops this other society from doing this thing, then return home, either learning to accept what the original society does (because it’s not as bad as that other society) or becoming a leader in the original society, making quiet changes to the original society that will fix everything.
The second society is the false doppelganger; the writer makes the main character deal with issues in this other society rather than the first society, when the better choice would be to make the main character deal with issues in their home society.
Another example. Let’s say you have a story in which the main character has a more character-driven journey than anything else, and the characters that your main character encounters are related to that inner journey. The main character meets multiple people who all teach them the same lesson, because the main character never responds to the lessons from the earlier characters: a character who lacks self-confidence meets characters who reaffirm her abilities, desirability, etc., over and over. Those characters are false doppelgangers; one person to represent one lesson should suffice. In addition–while it’s nice having other people help you build up your self-confidence, the main character cannot, finally, become self-confident while relying on the opinions of other people.
I’m tempted to lump in multiple climaxes as false doppelganger endings, but I think that that’s just different enough that I’ll leave it out. But oh, they’re annoying. The trick is to time the endings of your subplots so they’re all near the end. Endings should be near the end, not starting in the middle. Don’t wind up subplots before their time, or you’ll be tempted to start another subplot with another character, eerily similar…