It is intuitive in storytelling to suggest that a character, who you as writer have deemed the hero, is in fact morally upright or ‘one of the good ones’ (“JUST LIKE ME!” the audience member gasps, hopefully) through example. If he’s the hero, and it’s not till deeper into the story that he truly gets to take on the comparative bad guy or fight for what’s right, plop in a few acts of kindness or otherwise encouraged deeds to get the point across, and sway the viewer’s favor where it needs to be early.
This makes up the titular principal of Blake Snyder’s ‘Save the Cat! The Last Book on Screenwriting You’ll Ever Need’, a moment-by-moment deconstruction of Joseph Campbell’s Hero’s Journey as a screenwriting template. From his book: “Heroes should be introduced by a selflessly heroic moment in which they ‘save a cat’ or similar, to show they’re a good person…
The poignancy doesn’t need to happen on page one, and the character doesn’t need to (and shouldn’t) be a saint, but readers need to feel something for them. In screenwriting, this is called saving the cat. The protagonist can yell at old ladies, steal from a blind man’s cup and cheat at cards, as long as they go out of their way to save one creature from discomfort. Start watching for it in movies. You’ll find that in the first ten minutes, the lead character will enact some version of saving a cat.”
And while the trope is less common today, as screenwriters avoid tropes which could come across to audiences as emotionally manipulative, and is almost never used with an actual animal anymore, on one front Save The Cat is alive and well: the anti-hero. Coincidentally, those have been multiplying since the ’90s.
Let’s take the absolutely massive success of 2019’s ‘Joker’, for instance. The main character, birthday party clown Arthur, saves the cat for quite a lot of that film, to be honest, but a good example is his kind treatment towards his co-worker Randall, who is a little person and taunted by the other clowns. Audiences were better able to sympathize with the unwell Arthur, due to, what is framed through a film from his perspective, his righteous anger at cruel people and his empathy for the people they demean.
Later in the film, after killing the co-worker who got him fired, Arthur lets Randall leave unharmed (by this point in the story, this passes for mercy). The audience not only has a chance to connect with Arthur’s feelings of victimhood, but internalize how the character justifies his later actions, and becomes an idol to the downtrodden of the city (or at least imagines he does).
So, save the cat is less about proving the protagonist is a good person and more with getting the audience to believe that they agree more with their integrity than with most anyone else’s, especially more than the
antagonist’s.