Think of a play like a river...

I could tell I lost a couple of you on this analogy yesterday: what's with Jenny? Is she nuts?

A play, like a river, is about movement.
It will, inevitably, end.
It will, ideally, end by feeding into something much bigger than the play itself.
It gathers energy as it progresses. And it is the product of its many tributaries.
You want ALL of the elements of your play to CONVERGE, in one way or another, around the CENTRAL PROBLEM of your play. As tributaries feed into the main flow of a river, and push it, with increasing energy, toward the ocean, so should the characters, side plots, symbols, minor events of your play gather around your central idea and push it forward.

Just as a river loses force when streams drain away from it, so too will your play lose force if its characters, subplots, symbols and events DISPERSE AWAY from your central story.

Your goal is to end up at the ocean.