If you say in the first chapter that there is a rifle hanging on the wall, in the second or third chapter it absolutely must go off. If it's not going to be fired, it shouldn't be hanging there. - Anton Chekhov
The 1994 movie Pulp Fiction cold-opens in a restaurant booth, in which a charming couple is sharing breakfast. As the man ("Pumpkin," played by Tim Roth) and woman ("Honey Bunny," played by Amanda Plummer) converse, it quickly becomes apparent that not only is this duo a pair of career criminals, but that they're contemplating robbing the very restaurant in which they're dining. Within seconds, the audience learns two things: First, that this is not a family-friendly movie, and, second, that the lovey-dovey couple differ on their preference for revolvers versus semi-autos.
Although the firearm itself, a Smith & Wesson revolver, is unremarkable, there is something about its presence in the first moments of the film that's definitely interesting: It seems to subvert the "Chekhov's Gun" trope. The trope, quoted above, doesn't necessarily have to refer to a gun—it can be any object imbued with symbolic meaning. In this case, it's a literal gun, and although the viewer gets several good, long looks at it (a couple of times, from the vertiginous head-on camera angle), it's never fired.
So why would Quentin Tarantino, the director, include it in the opening and closing sequences of a movie that is not only chock-full of popular-fiction tropes but also named after one? It's probably a very deliberate and very clever subversion of the rule by Tarantino: Due to the fact that the movie's entwined storylines are presented out of sequence, the "Pumpkin and Honey Bunny" scenario is actually chronologically among the later events of the picture. So, although the viewer sees Pumpkin's S&W first, in "real time," it is actually among the last firearms to make an appearance. Telling our readers which of those might be considered the "real Chekhov's gun" would definitely count as a "spoiler," even 29 years after the film was first released!