Spielberg shows us the tanks many times, not lingering on them so long as to be obvious, but reminding us over and over that they are there. There are oxygen tanks clanging around on board. In the climax of the film (not the first act, as the rule is a bit flexible), Martin Brody ( Roy Scheider), Quint ( Robert Shaw), and Hooper ( Richard Dreyfuss) are on The Orca, looking to kill the murderous great white shark. Let's take Steven Spielberg's Jaws for example. Look at any of your favorite movies, and chances are, in many of them, you will have a 'Chekhov's Gun' trope moment. Not doing so is a massive disappointment that only confuses movie watchers. You can't have a gun shown, only for it to then disappear and never be seen again, or else what is the point of even showing it? If a gun is seen in a movie, you know at some point, usually in the second act as a move that forces the plot, or at the end when it's needed the most, it's going to be used.

If you hint at something show something big in your writing, or in a movie, you have to do something with the hint. The meaning of Chekov's gun is pretty straightforward. That style involves the trope of 'Chekhov's Gun.' The trope comes from this writing rule from Chekhov: “If in the first act, you have hung a pistol on the wall, then in the following one it should be fired. Heck, you can even see it in professional wrestling. In fact, you can find Chekhov's style in anything from horror to Marvel movies. It's not overly complicated like some of his work could be. The most enduring part of Chekhov's style is one you might not even be aware of.

Chekhov books