In screenplay writing, Desire is what will help form the Spine of your story. From the getgo, in Act 1, this Desire is what drives your Hero in his Ordinary World. The Desire of your Hero is then seized upon by the Inciting Incident of your story, which is the “match that lights the fire” of the Desire. The Inciting Incident is an external event, which will ultimately catapult your Hero with a slightly changed external Desire into the world where most of the story will take place: in Act 2 and Act 3.
In “American Sniper,” it might look something like this: Although it is established early on that the Hero is a sharp shooter, the Hero’s Desire in his Ordinary World is to win rodeos. The World Trade Center is attacked by terrorists and 3,000 people are murdered in one day. The world stands still, in shock. The Hero is not one to stand still- Islamic terrorists are behind the murders- So the Hero, no longer desirous of winning rodeos, joins the Navy S.E.A.L.S. with a changed Desire: He’s going to Iraq to fight the evils of Islamic terrorism. Once in Iraq, his Desire becomes: Fight off the Islamic terrorists while protecting the backs of his fellow soldiers. His Desire to “protect” is intensified by his particular skill set: He is a spot on, fearless sniper. The Desire of the Hero of “American Sniper” stays with him until the end of the story, and the audience is at the edge of their seats during all three acts.
In crafting your story, your character needs to know what he wants. Once he establishes what he wants, he now has his Desire, which is his “end goal.” Unlike the Desire embedded in an emotional yearning, the Desire your Hero wants is an external Desire. Knowing what the external Desire of your story is will result in your audience rooting for the Hero. The Desire will be the force that creates the Spine of your story; it creates focus; it gives clarity to your story.
Examples of a Hero’s external Desire: To win the gold medal in the Olympics; to get the girl; to reach the top of Mt. Everest; to get a divorce; to win custody to see his children; to find the person who murdered his wife; to discover a cure for cancer; to protect a witness from a murderer; to slay 10 dragons who are keeping his family hostage; to consummate an illicit affair; to take over a family mafia business; to get to the truth behind child abuse by pedophiles.
However, just like “real life,” it is a tough challenge to figure out one’s Desire. So the Hero’s Desire in the beginning of the story might be: To drink and play the rodeo circuit: “American Sniper”; to get into trouble with the ex-wife which will preclude getting child custody rights: “Mrs. Doubtfire”; to stay as far away from a Mafia family as possible: “The Godfather”; to bury the truth about pedophiles destroying children’s lives because it goes against tradition: “Spotlight”; to ignore the love of his life for a more shallow goal of making money: “Jerry Maguire.”
Therefore, the Hero’s Desire is not clear in the beginning of your story. The Desire that your Hero has in the first few pages of the story will get “ramped up” after the Inciting Incident, which comes about 10, 11, or 12 pages into the story. The Desire doesn’t completely change, but rather, it takes a “bend in the road.” By the end of Act 1, or about 30 pages into the story, the Hero will have the beginnings of a Plan and also a more clearly defined Desire.