I love to teach structure, and Joe’s post on Wednesday brought up a tremendously important question. Someone in another writing forum wanted to know how you figure out where to end Act 2, and go into Act 3.

The question of where the act breaks go, and what they entail, may be the most crucial in all of dramatic structure, because if they are weak, the entire edifice of the story will be unsound. Knowing how to fix them will go a long way toward making your novel more readable.

Think of novel structure as a suspension bridge.

As is obvious from the picture above, the suspension bridge is held up primarily by the two supporting pylons, one near the beginning of the bridge and one near the end. Without these pylons in those exact spots, the bridge will not be stable.

Now looking at the picture you can see that it perfectly represents the 3 act structure. A solidly constructed novel will look just like a solidly constructed suspension bridge. If that first pylon is placed too far out from the beginning, the first “act” of the bridge will sag and sway. In a book or movie, it means the first act is starting to drag.

Similarly, if the second pylon is misplaced, you’ll end up either with anti-climax (the pylon too far away from the shore) or a feeling of deus ex machina (the pylon too close).

In my book, Plot & Structure, I refer to these pylons as “doorways of no return.” I wanted to convey the idea of being forced through doorways, and once that’s done, you can’t go back again. Life will never be the same for the Lead. If you don’t have that feeling in your story, the stakes aren’t high enough.

Now, the first doorway is an event that thrusts the Lead into the conflict of Act 2. It is not, and this is crucial, just a decision to go looking around in the “dark world” (to use mythic terms). That’s weak. That’s not being forced.

A good example of a first doorway is when Luke Skywalker’s aunt and uncle are murdered by the forces of the Empire in Star Wars. That compels Luke to leave his home planet and seek to become a Jedi, to fight the evil forces. If the murders didn’t happen, Luke would have stayed on his planet as a farmer. He had to be forced out.

In Gone With the Wind it’s the outbreak of the Civil War. Hard to miss that one. No one can go back again to the way things were. Scarlett O’Hara is going to be forced to deal with life in a way she never wanted or anticipated.

In The Wizard of Oz, it’s the twister (hint: if a movie changed from black and white to color, odds are you’ve passed through the first doorway of no return).

In The Fugitive, the first doorway is the train wreck that enables Richard Kimble to escape, a long sequence that ends at the 30 minute mark (perfect structure) and has U. S. Marshal Sam Gerard declaring, “Your fugitive’s name is Dr. Richard Kimble. Go get him!”

The second doorway, the one that closes Act 2 and leads to Act 3, is a bit more malleable, but just as critical. It is a clue or discovery, or set-back or crisis, one which makes inevitable the final battle of Act 3. It is the doorway that makes an ending possible. Without this, the novel could go on forever (and some seem to for lack of this act break).

In The Fugitive, at the 90 minute mark (the right placement for a film of just over two hours), Kimble breaks into the one-armed man’s house and finds the key evidence linking him with the pharmaceutical company. This clue leads to the inevitable showdown with the “behind the scenes” villain.

In High Noon, the town marshal reaches the major crisis: he finally realizes no one in the town is going to help him fight the bad guys. That forces him into the final battle of Act 3, the showdown with the four killers.

By the way, this structure works for both “plot driven” and “character driven” stories. It’s just that the former is mainly about outside events, and the latter about the inner journey. But that’s beyond the scope of this post.

Now, there is always some well meaning literary genius howling in protest at the idea of structure. Too rigid! I don’t write by formula! I am a rule breaker, a rebel! An artist! Away with your blueprints and let me run free! The 3 act structure is dead!

Let me say, first, I understand this artistic impulse. A good writer is a rebel, someone out to make waves.

But let me also say that the literary waters are littered with the works of those who ignored the basic principles of the suspension bridge. Unreadable novels with pretty words that didn’t sell.

You want to write an experimental novel? Go for it. Just be aware that not a whole lot of people are going to care.

What they care about are characters, dealing with trouble by fighting their way over a bridge—meaning, through a plot that matters and is laid out in the right way.

Structure is “translation software” for your imagination. You’ve got a great story in your head. The characters, the feeling, the tone, the gut appeal, the thing you want to say. But it means squat unless you can share it with other people, namely, readers.

Structure allows you to get your story out with the greatest possible impact.

“But that’s formulaic!” Well guess what, Skippy: formulas are formulas because they work. Try making an omelet without eggs. What you, the writer, need to do is get people so caught up in the characters and stakes that they can’t see the structure.

Many published authors know this instinctively. But if there are problems with their novels, they may not always know where to look for the fix.

Is the first act slow? Does the novel take too long to end? Does act 2 seem interminable? Is the ending anti-climactic?

Most likely, the problem is structural. Get a grip on it, and your writing will only get stronger.

Your novel, in other words, won’t end up as a bridge to nowhere.