Setup and payoff

A setup is a detail, capability or promise planted early so that a later moment can spend it, and the payoff is that later moment — the return on something the reader was shown in advance.

Chekhov's gun is the negative form of the rule: if it never pays off, cut it. Setup and payoff is the positive one, and it does something Chekhov's version does not — it generates tension in the gap.

The mechanism only works when the reader can see the payoff coming. Have the hero stash weapons along her escape route before the fight, and the audience now knows she will have to use them; every minute before she reaches that corridor is spent waiting for it. The anticipation is the effect, which is why a roller coaster starts with the climb. A payoff the reader could not have predicted is a surprise, and surprise is over in five seconds.

Two failure modes. A setup that is too visible reads as a signpost — the reader stops watching the story and starts watching the machinery. A setup that is too buried gets forgotten, and the payoff arrives feeling like a coincidence, which is a deus ex machina with a receipt.

The usual calibration is to plant the detail while the scene is busy with something else, so the reader stores it without being told to.