Is there a niftier narrative trick than when a movie plays out in real time?
Well, yes: it's significantly impressive when a film makes sense than when it relies on a gimmick.
But if you've got a good story and characters worth caring about, real time can be an interesting and innovative way to frame a tale.
Take Psycho helmer Alfred Hitchcock's famous mystery Rope. This unbearably tense thriller is told in a few seamless, absurdly long cuts, and its (almost) real time presentation manages to turn what could have been a thin story into an incredibly tight and atmospheric genre classic.
With that in mind, this list is looking for successful examples of real time storytelling from the genre which the narrative technique is most suited to. Since horror flicks tend to typically feature compressed action which takes place over a few days at most, the genre is ripe for real time storytelling.
Of course, there are only so many movies which can pull off this audacious trick, and precious few worth recommending.
So some of these flicks feature brief prologues and other rule bending, but that's an inevitable sacrifice in dredging up the ten best horror movies told (mostly) in real time.