In old Saturday morning cartoons, a character would face a dilemma. That’s when an angel and a devil version of that character would appear on his or her shoulder and whisper advice. The devil version of the character would suggest a selfish decision while the angel version of the character would suggest a selfless decision.
That kind of dilemma is exactly what your hero needs to face. Essentially, tempt your hero into doing something evil.
In “Die Hard,” there’s a sleazy character who’s trying to get to know the hero’s wife. When this sleazy character talks to the villain and gives the villain the name of the hero, the hero has a reason to let this sleazy character die. However, the hero actually tries to save his life by claiming he means nothing to him (which is actually true).
Because the hero tries to save the sleazy character, despite the sleazy character helping the villain, the hero comes off looking good even though the villain kills the sleazy character anyway.
In “Terminator 2,” the hero (the good Terminator) has plenty of chances to kill people but refrains from doing so because of orders from John Connor. Because he doesn’t kill anyone, the hero further shows he’s good.
By tempting your hero into doing evil and becoming like the villain, the story creates conflict and tension. In “It’s a Wonderful Life,” the villain tempts the hero with a big salary if the hero would only come to work for him. That tempts the hero who’s tired of being poor, but when he realizes that the villain just wants to get him out of the way so he can exploit the rest of the town, the hero refuses to be tempted.
In “The Greatest Showman,” the hero (P.T. Barnum) is constantly trying to prove himself to others who insist he’s nothing but a con man. So when the hero meets a singer who finally makes the hero look good and acceptable to society, this singer tempts the hero by trying to get romantically involved with him.
Because the hero has a wife and children, he ultimately turns this singer’s attempts away, proving he’s good.
Temptation is always a good tool to use against your hero. In “The Return of the Jedi,” Darth Vader tries to tempt Luke into joining him. In “Tootsie,” the hero is tempted to continue his deception by pretending to be a woman and remaining popular and wealthy.
In your own screenplay, find a way to tempt your hero into doing evil. Then when the hero refuses to do evil, he or she will wind up looking better in the audience’s eyes, who will then root even harder for the hero to succeed.