My favorite version of that is The Handmaid's Tale. The background is supposed to be that the story was constructed from audio cassettes recorded by the narrator that were found unlabelled all jumbled together so the order had to be guessed at.
I guess it's less likely to fool you when the setting is the future, but it's pretty nifty.
It's a very common literary technique. In fact, the earliest novels were often epistolatory novels which operated under that conceit - that you'd stumbled across a stash of letters in your grandmother's attic.
Fantasy and science fiction novels in particular favor that trope.
Lots of "rediscovered" Sherlock Holmes stories are tales that the "editor" found when he stumbled across a stash of Watson's papers. Personally, I find the "footnotes" that get put in those stories--I'm looking at you, Nicholas Meyers--to be masterbatory self-indulgence, because anyone familiar with Holmes knows the "editor" didn't spend hours toiling over some eccentricity in Watson's handwriting.
It's a very common literary technique. In fact, the earliest novels were often epistolatory novels which operated under that conceit - that you'd stumbled across a stash of letters in your grandmother's attic.
Dracula! All letters and journal entries.
Gene Wolf also uses this trope in his "New Sun" series. It's supposedly reconstructed and translated from manuscripts from the far future brought back to the....slightly nearer future. Somehow.
Yeah, all of Wolfe's "___ of the ____ Sun" books have some kind of narrative frame like that. And they all wrap around and connect to each other eventually in what is I'm sure a really impressive way if only I could follow it.
I love the guy, but those books are dense.
It's a very common literary technique. In fact, the earliest novels were often epistolatory novels which operated under that conceit - that you'd stumbled across a stash of letters in your grandmother's attic.
Far too common nowadays I'd say. I'm really tired of it. Just tell a story already.
The only way that device could be better is if the filmmaker made the reading of the letters a montage to "Halleluiah".
I can't believe no one's yet mentioned the Griffin & Sabine books.