How much do you need to know about a character before you can write about them?  A lot of books on writing urge that you develop detailed biographies of your characters, covering everything from the first time they went to the dentist to the state of their bowels. 

I’m not convinced.  What matters isn’t the quantity of what you know, but the quality.  And most of all, how your character will react to the events that you put them through in your story.  Which makes sense: a person’s choices determine their character, rather than it being a Platonic absolute.

Besides, who could honestly say that they can separate out character from story?  The two are entwined in writing, or at any rate should be.  If not, then you’re in danger either of reeling out heaps of backstory that changes the present situation not a jot, or losing sight of what the story is about by unrolling plot complexities.

Neither of those extremes is to be welcomed.  Think how little you can get away with: Lee Marvin in Point Blank is defined totally by his need to put things right in his eyes.  Never mind the odds, he’s going to see that he gets his dues.   And that stance defines every choice that follows.  It’s not sophisticated, but it’s hugely effective.  Same goes for the characters Mifune plays in Kurosawa’s films: we don’t know a great deal about their backgrounds, but their actions right here right now speak volumes.  And that’s what counts onscreen.

The need for extensive character background is symptomatic of the influence of psychoanalytic theory on writers.  English students have to put up with more Freud than psychology ones do, for the most part.  And it’s in many ways a pernicious influence.  This is before we get into the kind of stuff peddled by Kristeva and other French theorists, arguments against academic tenure if ever I came across them. 

I can, I guarantee you, come up with a half dozen or more explanations for why anyone does anything.  Doesn’t mean that any one of them is true.  Let alone that I believe any of them, save the most unlikely, which at least I’d have some fondness for on the basis that its unlikeliness makes me less inclined to take it seriously.

Besides, stories work at their best when characters behave in unexpected ways.  Someone who zigs when you’re expecting them to zag is interesting.  And all of this is in the remit of that most basic of the brain’s functions; pattern detection. 

You don’t need polysyllables, reference to dimly understood science, or echoes of long dead poets to tickle the brain; just present it with things that don’t fit whatever models it may have been encouraged to develop over time.  That way lies stimulation, which an audience will like you for.  And which your own brain will like you for coming up with, for that matter.

That said, not everything should be a surprise.  That way lies overload, as anyone who’s tackled Finnegans Wake can testify: not even the individual words can be trusted there.  Some of David Lynch’s work has a similar effect on me: there comes a point when you’ve been dazzled so much that it becomes old hat.

Notably, both Joyce and Lynch go so far in their experiments that they effectively abandon story, or go meta to it or something equally clever.  Which there’s a time and place for, but not one that I’m especially interested in as someone intent on making films that audiences will relish. 

The bottom line where screenplays are concerned is establishing some fixed points for the audience, and not turning over too many of them.  Ration out your surprises: The Crying Game’s works brilliantly, and wouldn’t be assisted by the reveal that one of the characters is from another world. 

And all of this brings us back to where we started: with character.  A friend who enters into a polyamorous relationship is one thing.  If they do so at the same time as standing for election as a BNP candidate it might be a bit too much to take in.   One rule of thumb I picked up from writer Michael Eaton is that the protagonist of your story is the one who the biggest change happens to.  Figure that out, and odds are you’ll be writing the story an audience wants to know about.