In case any of us have forgotten, the screenplay mantra is SHOW DON’T TELL.
In screenwriting there’s always a choice between writing dialog to tell your story, or writing actions, emotions, images, sights, sounds, and visuals to show your story.
The choice is always: Show Don’t Tell…Show Don’t Tell….Show Don’t Tell.
But, there are times when story facts and details must be relayed to the audience via characters’ dialog…a.k.a. exposition.
So, the writer needs to deliver this exposition to the audience in such a manner that the audience doesn’t suspect that’s what the writer is doing.
If the audience recognizes they’re being fed exposition, it diminishes their enjoyment and emotional involvement in the film.
Hence exposition must be delivered with guile and subterfuge.
This can be done by making certain the character who is telling the information is telling it to another character who doesn’t already know that information.
And doing so while some interesting actions are unfolding on-screen.
The kitchen spigot bursts and water blasts all over the place. While the characters scramble to solve the problem the necessary exposition is delivered.
Or, the two characters are on a dangerous precipice scaling Mount Everest while the necessary information is revealed.
Or the character delivering the information does so while he’s performing the Heimlich maneuver on a choking patron of the posh restaurant where they’re having a meal.
In this way, the audience doesn’t realize that the only purpose for the scene in the first place is to relay the needed exposition to them.