Wiktionary
n. An element introduced into a story, film, etc. to advance its plot.
Wikipedia
A plot device (plot mechanism) can be anything which moves the plot forward. A contrived or arbitrary plot device may annoy or confuse the reader, causing a loss of the suspension of disbelief. However a well-crafted plot device, or one that emerges naturally from the setting or characters of the story, may be entirely accepted, or may even be unnoticed by the audience.
Usage examples of "plot device".
True, the plot device workedbut it bypassed what I saw as a rich opportunity to learn more about the Klingons.
If I wasn't of the opinion that coincidences are merely chance or an overused Dickensian plot device, I might conclude that an old enemy of yours wants to get even.
But the marriage is a necessary plot device, and Gradgrind's stony reaction--believable or not--is important to making it happen.
Is this merely a plot device, or did you have something else in mind?
Avi looks like he is wasting away from some vague disease invented as a plot device by a screenwriter.
It's an obvious plot device meant to reveal the motivations of other characters.
Saddam's yacht managed a little of the old Austin Powers super-villain flash, though, boasting a secret underwater escape-hatch (though the mini-sub, my Plot Device noted, is *missing*) and a private operating theater with a black leather operating table (maybe this was for tweaking the doubles into more Saddamoid parameters?
Yet did not Massood storytelling utilize conflict as motivation and plot device?
He is the unmoved mover, the unseen organising principle, like God, and, like God, up he pops in person, one fine day, to introduce the essential plot device.
In fiction, just a plot device, of course, to reveal the full extent and implication of the story to the waiting audience.
What I am in fact is the oldest but most effective plot device of the trite world.
That was not so much a plot device as just what's going on with them.
But mostly it's that she returns wonder and true danger to the plot device of mortals interacting with Faerie.