PosterPage? definition: A device in the sense of a strategem or conceit, rather than in the sense of a machine. This device is such that it moves the plot along in a desired channel. The classical example of a plot device is "another dead body is found"
"A dead body is missing" is more interesting... -- Senji
Arguably. It might be a good use for this page to list those devices which we have (seen) used to good (and bad) effect, and why we think that was? --Vitenka
Of course, there's nothing stopping the PlotDevice from also being a physical device - in which case it is often a McGuffin. If such a device also affects plots from within the story then you are getting all weird and SelfReferential?. Well done. --Vitenka
Or: A machine for putting Data onto a Graph.
Some sample devices.
MistakenIdentity - Someone gives something (physical or information) to the wrong person. Then either that person acts on it, or the giver realises their mistake and tries to rectify it, or someone else gets involved, or all of the above. Well used in comedic situations, but also a good way to kick off a serious thriller style plot.
/InarguableProof? - Some well known or presumed fact is proved, beyond a shadow of a doubt, to be untrue. The main suspect in a serial murder case turns up murdered, for example. A bit heavy handed, perhaps - but it certainly jolts the plot.
The train station in The Matrix. It makes no sense for it to exist, but Neo getting stuck there provides a good excuse for a fight scene at the Frenchman's place. CategoryPlotElement, I suppose, pretty much by definition...
Well, presumably it's composed of multiples of that --Vitenka