Shaping a story by the 'rule of three'

Here's an article on writing novels that I found extremely helpful.

It's a way to combat an over-active creativity by keeping a novel focussed on the simple progress of its story, rather than on fun and interesting side-alleys. The three things to steer by are simply (1) a protagonist (2) a conflict and (3) a setting.

It's interesting to see how this plays out in giving books unity and narrative force. For example:

The entire Harry Potter series: (1) Harry (2) Voldemort's struggle to take over the earth (3) the magical world.

The Bible: (1) God (2) Reconciling himself to his errant creation (3) the whole canvas of heaven, the universe and eternity.

I think some stories break this rule by doubling it. So:

Pride and Prejudice: (1) Elizabeth Bennet (2) Overcoming pride and prejudice to marry Darcy (3) Eighteenth-century aristocratic England

--and--
(1) Mr Darcy (2) overcoming pride and prejudice to marry Elizabeth (3) as above


Similarly the parable of the prodigal son has two rules of three:

(1) Younger son (2) Returning to the Father (3) the Father's farm

--and --


(1) Older son  (2) Becoming further estranged from the Father (3) the Father's farm.

Either way, sticking to these simple outlines has to give a story narrative energy and stop it wandering off...