I'm working on a story with a large cast of characters (or at least, it will be large by the end of the series) and I want to make sure that I can make them all different, unique, and very, very flawed. However, I tend to run out of ideas for nuanced character flaws very quickly. (By nuanced, I mean something that actually affects the character to a meaningful extent, so not something like being clumsy - the more psychological flaws, i.e. having a huge temper.) So I figured I'd ask for everyone to list interesting character flaws they've come across, or ideas they've had, or just something they thought of while reading this - not just for me, but for anyone who's struggling with making nuanced characters. I guess I'll start with one, since that's something people normally do when starting lists: Very negative - cynical, pessimistic, can't enjoy anything because they're always thinking of how it'll go badly
To me, an interesting flaw is a misplaced strength. For example lets say a character is trusting. They can make friends easy because they believe in people. But pit that against a character who takes advantage of the trust-- well now your character has made a huge mistake and there are problems. Thus, plot! Or you could invert it, a suspicious character disbelieving someone who's being genuine and that causes problems. I read somewhere and it stuck with me, that flaws and strengths are really one and the same thing-- it just depends on what situation the character is in. Your negative and cynical character would be good at seeing how things could go wrong, and in a high-stakes situation where they have to be careful of their every step that would be helpful. Less helpful when they're at a rest point and can take a break.
Pollyanna - His/Her world is rose-tinted and they see only the best of everything. Naïve is the color of this person's flaw. Other characters will likely engage the person as displaying toxic positivity. There is often also a mirrored side to this character. The pollyanism is just a veneer for a person who is quite damaged inside, using positivity as both a shield and a disguise.
There are very few flaws that are just bad with no gain anywhere. Even being selfish can be a gain and a strength in some circumstances. Self-sacrifice may seem like a good strength but it could also be a deadly weakness and flaw in a certain circumstance. My Mum's biggest flaw, and she'll admit it, is her quick temper. Sometimes her temper has paid off, her temper is like the force of God and people know pretty quick not to mess with her, to not try a fob her off and that gets problems solved. Equally, it means she can fall out with people easily or get the opposite reaction where people become resentful of her combative attitude and she gets nowhere. So just about any flaw being that and a strength is interesting to me. A character who is the only survivor because his selfishness saved his life, those who cared and went back to save the others all died. That kind of thing gets me. Also a flaw that means something. A flaw that gets them into problems and with out that flaw maybe the plot wouldn't have happened.
I tend to find developing character backgrounds easier than flaws; backgrounds will eventually and inevitably offer you a set of flaws to choose from. It is even better if the "background" is played out on screen and the character flaw is acquired during the narrative. Character development we all love; should not only lead to triumph but also to a fall from grace or a decline in a sense. It also helps us connect with a character and paints them more real; a man who survived assassinations may become paranoid, a soldier could become a staunch opponent of war and a disenfranchised person can become narcissistic and hateful. Another good choice is to play around with flaws that become strengths, and strengths that become flaws. In my world, honest and just characters are respected proper - but when they enter politics, they are usually stomped down and abused until they are chewed out and thrown into the mud title-less. These subversions can allow your character to interact with their weaknesses and flaws and develop them even faster / more profound.
