To simplify writing multiple characters, focus first on your hero. Once you know what your hero wants and what type of person your hero is, then you automatically know what all of your other characters are like since the hero, mentor, and ally should all be alike.
In “Lilo & Stitch,” Lilo is an angry girl who causes trouble. Not surprisingly, Stitch, the alien from another planet, also causes a lot of trouble because he’s been genetically designed to be destructive. Lilo and Stitch are basically the same character.
Look in every good movie and you’ll find this similarity among all major characters. In “Terminator 2,” the hero (the good Terminator) needs to learn to solve problems without killing, which is the exact same lesson Sarah Connor needs to learn as well. In “Little Miss Sunshine,” the hero (the little girl) has a dream of attending a beauty pageant. Her brother has a dream of becoming a pilot and her father has a dream of becoming a successful motivational speaker. They all have dreams because they\’re all basically the same.
The reason why good movies create multiple characters who are basically the same is so all the characters support the same theme. If you have wildly different characters, they’ll create wildly different themes, and then your story will be disjointed. Although audiences might not be aware of this disjointedness, they’ll feel that something isn’t right because the story doesn’t focus on a single theme. Movies without a strong theme tend to be extremely forgettable.
“Titanic” wasn’t a smash hit because it was about a sinking ocean liner. It was a smash hit because of its strong theme of living your life on your own terms. The hero (Rose) wants to live her own life but doesn’t know how. Her lover knows how so he teaches her. Yet the hero’s mother does not know how to live her own life, so that’s why she’s trying to make Rose follow in the same path in life that she did.
So when you create characters, your other characters either mirror your hero or are the complete opposite so they can teach your hero how to achieve his or her dream.
In “Die Hard,” the hero is afraid of flying. Later he meets a black policeman who\’s afraid of drawing his gun after he accidentally shot a kid who had a toy gun. The hero redeems himself by defeating all the terrorists. The black policeman redeems himself by shooting the last terrorist. Even the limousine driver redeems himself by crashing his car into a terrorist.
In “Legally Blonde,” the hero is looking for love, and so is her friend the hair dresser. The villain (the law professor) is also looking for love by using his position to get the hero in bed.
When creating characters, think equal or opposites. Your other characters are often mirror images of your hero, or opposites of your hero so they can teach your hero. In “The Karate Kid,” the hero wants to learn how to fight while his mentor (his karate instructor) wants to help him as a way to help himself.
When your characters mirror each other, then they help support a single theme. Stories with a single theme tend to be stronger than stories with no theme or multiple themes that confuse audiences.