Jen and I went to see Pirates of the Caribbean: On Stranger Tides yesterday. It's a fun movie, but the first is still the best of the lot, and I don't think it quite manages to match the second and third installments.
It got me thinking, though, about Chekov's Gun. Without giving anything away, On Stranger Tides features a number of dropped Chekov's Guns; plot elements that are made to seem significant at the time, leading the audience to expect something more, and then turn out to have no real importance to the story. When writing a story, it's important to ensure that your Chekov's Gun goes off before the end of the final act.
Following the rules for Cheov's Gun when writing a book is about more than just adhering to narrative theory. It's about set-up and reward. When you entice the reader with something, you need to let them enjoy the results, otherwise you're trailing them along like a donkey with the proverbial carrot-on-a-stick. The donkey sees the carrot. The donkey wants the carrot. In order to have a satisfying story, the donkey must eventually get to eat the carrot. If not, sooner or later the donkey gets tired of chasing the carrot and does something else.
Sticking with the Pirates series, in Curse of the Black Pearl we have a literal Chekov's gun. In this case, it's Jack's pistol. It's made clear early on that he is carrying a pistol with just one shot's worth of powder loaded, with no extra ammunition, and this pistol is one of the few things he insists that no-one ever lose or let him go anywhere without. Later we find out why: it's the pistol Barbossa gave him when he was marooned, and Jack's been saving that shot for his former first-mate. At the film's climax, we get the payoff for all that set-up. Jack outwits Barbossa and uses his one shot to kill him, finally getting his revenge.
The series is rife with more examples, but this is the most clear. Others include Will's medallion, the "touch of destiny" Tia Dalma senses in Will, the method by which the Flying Dutchman gets a new captain, even Elizabeth's corset in the first movie. These elements are all shown or described early on and then feature in plot development later. That's the payoff. The audience won't always spot a Chekov's Gun, but when they do, the expect to see it go off. If it doesn't, then they wonder why it was even there to begin with.
Keep your Chekov's Gun loaded and ready. Don't always let it be seen, or make it obvious when it's going to go off. But make sure it goes off. Otherwise take it off the mantle and out it away. It doesn't need to be there.