A lot of writing gurus will tell you a character for a fictional work cannot be one dimensional. They will tell you a good protagonist is a complex, evolving creature. It is my humble opinion that this is utter BS. I say: keep it simple.
Here is my argument: the most monumental protagonists in the history of writing or screenwriting can be summed up in two personality traits, three max. All the rest is part of situation, plot, setting or filler. A few examples:
Lisbeth Salander: socially inept, smart, Gothic (okay Gothic is not really a personality trait, but it is too important for the ‘face’ of this character not to mention it).
Anna Karenina: beautiful, passionate.
Jack Sparrow: Extremely opportunistic.
Mister Darcy: proud, honest (and mostly rich, really)
Those are the traits that make these characters stand out. That is why you will always remember them.
Then, almost always, those personality traits are challenged. Usually by making them do or say something that’s completely the opposite of their normal behavior. That’s what gives them a semblance of humanity, and of complexity.
Lisbeth Salander falls in love, Anna Karenina is stuck in a passionless marriage, Jack Sparrow does something nice, mister Darcy falls in love with a woman that is considered beneath him.
And just to be complete: I do think growth in a character is necessary. Usually this growth is simply achieved by the opposing force I explained in the paragraphs above.
I wonder what you all think of this theory. Feel free to oppose! (Agreeing is also permitted.)