I think it just depends on how âhumanâ your characters are. And how human your characters are depends on what kind of actions they take.
Your character must take big actions (Something that moves the plot forward - I.e. the story starts off with your character murdering someone, and get put in jail) or small actions (this shows your charactersâ personality /quirkiness .i.e. carefully putting on make up in front of a mirror). But either way, whatever your character does, you (and the audience) needs to think,
If I were put in this situation/environment would I (or someone I know) do the same?
Maybe itâs a stretch - âI wouldnât personally do that, but I could definitely see my friend doing that. Or me when Iâm particularly stressed.â But thatâs how your build character.
If you want to portray character B as particularly stubborn, the audience should be able to subconsciously realize that a stubborn person would take the actions that character B takes.
Creating âlikeableâ characters is one thing. Weâve seen plenty of endearing, iconic characters that we all know and love - like Joker, for example. Heâs a nutjob and you canât exactly understand his motives on a personal level, but he is full of charisma and personality either way.
Creating characters that your audience actually CARES aboit is another thing. That depends on how well your audience can emphasize with the character. If something bad happens to him/her, itâll be like watching your best friend get fired from a job or lose a competition. Youâll feel bad, and youâll want them to keep trying.