On paper, dialogue is the most important part of the filmmaking.
Listening to characters talking—to each other, to themselves, to their pet rooster—is the easiest way to convey information, plot development, and humor. You can pull off all of the above without fancy camerawork, CGI, or the need for stunt doubles. Dialogue—along with sound effects and soundtrack—set the stage for our ears, completing the audible scenery that we take in without even thinking.
Properly crafted dialogue is an essential component, as it helps bridge the gap between movie and viewer, but using it to convey setting requires a careful hand and some restraint. It fills in the gaps between what we see on the screen and what we need to know to better understand the plot or the characters. Characters idly discussing a murder at a bar may foreshadow the grim mystery that will unravel for our protagonist, or murmured concerns about a child’s grades will indicate not all is well in a family home.
Dialogue can help set the scene and tell us more about a movie’s universe. For example, Obi-Wan Kenobi’s explanation of the Force as “an energy field…it surrounds us, penetrates us, binds us together.” His simple description gave A New Hope—up until then a sci-fi film—a mystical element.
Dialogue’s greatest use, however, is its ability to tell us about characters, whether it’s used directly (a character introducing himself: “My name is Frank”) or indirectly (characters telling us Frank should be avoided: “Frank murdered a guy and got away with it”). Dialogue fills in the blank spots and delivers tidbits that might otherwise never come to light.
Look at Merle Dixon from AMC’s The Walking Dead. He spits out virtually every line (unless he’s grumbling menacingly), and within his first few sentences, we can deduce that not only is he a Southerner and a racist, he’s also possibly off his rocker or high as a kite. Merle only appears in three episodes thus far, but one of his most memorable turns is when he appears via hallucination to his younger brother, Daryl:
“All them years I spent trying to make a man of you…look at you…you’re a joke is what you are…you’re…redneck trash, they’re laughing at you behind your back.” Merle continues his string of insults, seemingly voicing insecurities Daryl keeps carefully hidden: “Ain’t nobody ever gonna care about you except me, little brother, ain’t nobody ever will.”
In just a few lines of dialogue, we learn more about Daryl’s life than the man himself has revealed in ten episodes.