Hi there this is technically a question about a play rather than a novel, but as far as I'm concerned the principles of character construction are the same regardless of the medium, so I figured as seasoned writers and critics of fiction your advice would be very useful! Here goes: There are two main characters in the story I'm writing, and I want them to both be well-rounded. I've heard it said that for an audience/reader to properly become invested in a character, the character needs to have both agency and desire, i.e. we need to understand that they want something, and they need to be taking steps to achieve the thing that they want. I completely understand this, and I'm not having any difficulty with the agency side of things with my characters, but I'm not quite sure how the desire side applies to stories in which character motivations are necessarily fuzzy, i.e. psychological thrillers. Take Gone Girl, for instance: we know both characters are hiding things, that they're unreliable narrators etc., but it still works as a story and both characters are great. We are still invested in both of them even though we know we don't have all the pieces about them. So if I'm writing a story in which the audience's understanding of the characters' motivations is constantly shifting (and in one case, is only made clear right near the end), how do I make sure the characters are written well, like in Gone Girl, and don't alienate the audience when the audience realises that their understanding of the character motivations is inaccurate/incomplete? In particular, it is necessary for one of the two characters to only have her true motivations revealed at the end, because the reversal of expectations in this instance highlights the themes of the story, but I don't want the audience to feel alienated from her, I want them to understand where she is coming from, even though they only learn the truth about her right near the end. I don't want them to leave feeling distanced from her. But also, I don't want her to have to monologue about herself to get the point across. How do I square all these circles? Thank you in advance for any insights/assistance!!
The plot of the story should reveal early-on a goal or a problem for your characters. One character might be in need of money. Another might be in love. Another might be angry and seeking revenge. A hidden quality or secret about a character isn't a problem for me, as long as I understand the overall goal. Sometimes, characters surprise us at the end of a story by having a secret or an ulterior motive, but the overall goal should still be there. Establishing want in a character is easy if I can relate. For instance, if a kid is the only one in a group not given an ice-cream cone, I'm going to feel sorry for that kid. If a boy is in love with a girl, and she chooses to date another boy, well unfortunately I can easily relate to that one, too. The plot of the story, if it has a clear goal or problem to solve, and the behavior of the characters, should be enough to satisfy the audience.
What you need to focus on is sympathy. Motivation and desires and even the characters sense of agency will change as they develop. They start out wanting one thing, then when called to action, they seek revenge, finally in the reveal they see they have to save the universe. And that's a good thing and part of what character development is. So really what you want to get people into your characters is sympathy. Show the character being vulnerable, show them being human, show them struggling with what they are doing. Sympathy doesn't mean 'feel sorry for' by the way, it means 'feel like me'. Even characters who are very far outside the norms of reality, having moments where they share for a second the kind of feelings the audience would likely have in that circumstances; that will get you buy in. Forget about when and where motivation are shown and whether that get's people on board. Focus on sympathy; the juxtaposition of sympathetic character doing something unsympathetic will create interest and tension and mystery.
Apologies for the incredibly late reply. Thank you both for your extremely thoughtful responses - this has given me plenty to think about and I look forward to incorporating it into my story. Cheers!