The characters in your script, especially your lead character, should, according to most of the authorities in the field (the ones who make a living selling writing advice, as opposed to the ones who write and sell scripts) have an “arc”, a progression of growth/change/education that progresses them from someone who is NOT able to achieve the goals/needs that are set out at the beginning of the script to the person who CAN achieve those goals/needs.
Not that they necessarily WILL achieve them… this is called a “sad” ending, or a “realistic” ending (depending on which person you speak to).
The character at the beginning, according to this paradigm, should have both a noticeable flaw (say, a fear of snakes) and a hidden flaw (say, an inability to commit to a relationship). When confronted with the hidden flaw, the character should learn what it cost others as well as what it cost himself; when confronted with the noticeable flaw, the character should be able to “suck it up”, keep going, and get the job done in spite of the flaw. (Witness a certain Dr. Jones in a tomb in Egypt.)
And, to top it off, according to these same authorities, the character should have other idiosyncrasies that make them appear as a “rounded” character… with more than one dimension.
Now, not every character has this sort of story… and not every character has an “arc”.
The examples promulgated in the past were “franchise” characters, like Superman, James Bond, Napoleon Solo, Ilya Kuryakin (yes, I know, these two were from television… but TV had highly restrictive formats in those days)…
This, of course, has changed with long-format TV, multi-episode story “arcs” (something I’ll discuss further on), and less restrictions on what you can and can’t do.
So where does that leave us?
Change, for the sake of change, is not good. Change motivated by the events of the story, that comes from the beliefs, the strengths, and the flaws of a character, is good.
More to follow…