I’ve extensively discussed the role of your central character in terms of serving the central thematic concept and their interaction with the supporting characters. Here is an extract from Mr. Mini Movie Chris Soth, who expounds on how the supporting characters revolve around the main character (protagonist) as different the dimensions of him.
Chris calls them mirror characters because they possess antithetical character traits to your protagonist. Oftentimes, they come into play when the protagonist reacts to a situation.
You MIGHT think of creating a mirror character at each end of your hero’s character arc. That is, among your subsidiary characters might be one character who represents what your hero SHOULD BE, what he will be if s/he undergoes the change this story is driving them through, I think I called him the “YOU OUGHTA BE THIS GUY” GUY, but maybe we could call him “THE SHINING EXAMPLE” – AND –
— a character who serves as “THE CAUTIONARY TALE”. That is, a guy or gal who shows us, and perhaps our protagonist, what they will become if they DO NOT change and serves as a stark warning against the folly of proceeding through life as such a flawed character.
In Casablanca, we’ve got Rick Blaine (as portrayed by Humphrey Bogart), he’s an isolationist, won’t stick his neck out for nobody, and serves only his self interest, especially when it comes to the woman he loves, Ilsa…
HE OUGHTA BE: Victor Lazlo (as portrayed by Paul Henreid), a selfless freedom fighter, who sticks his neck out for everyone, everywhere – and who will gladly sacrifice anything, everything for the woman he loves, Ilsa Lund.
And in fact, it looks like this is who Rick will become as the credits roll, as his character arc has completed – “Where I go, you can’t follow, etc…” he’s off to become a freedom fighter, to take on the Nazis and fight for the little guy, as he used to before Ilsa broke his heart in the backstory.
But…if Rick keeps up his selfish ways, he’ll never be that guy. In fact, he’ll become:
THE CAUTIONARY TALE: Captain “Louie” Renault (as portrayed by Claude Rains). Here’s a man who “blows with the wind” and serves only his own self-interest…and when it comes to love – Louie’s happy to “whore out” any or every woman he comes across…and his doing so w/a young Bulgarian refugee serves as an object lesson for Rick at one point…
This is what Rick has to avoid – and in the end, Louie ends up changing too, and heading off into the future WITH Rick.
So, Victor Lazlo, Captain Renault…both mirrors to Rick Blaine. One is what Rick SHOULD be…the other, what he COULD become…
Characters are also defined in terms of the CHOICES they make? Logical ones? Reactive ones? Instinctive ones? These choices don’t exist in a vacuum because they must be compared to the choices other characters have made.
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