Why
A turn is not an event. It is a change in the situation such that the next scene cannot be the same as it would have been.
The most reliable test is the charge test: name the emotional charge entering the scene and leaving it, on a scale. If the two numbers are identical, no turn happened. This is deliberately mechanical, because "does it turn" is the kind of question a writer answers optimistically about their own work and a number is harder to argue with.
The second test is the state test, and it catches what the charge test misses. Describe the world in one sentence before and after. Charge can be nudged — a writer who wants to clear the first test simply adjusts the number — but two identical sentences are hard to lie about.
Turns come in a small number of shapes:
Information — someone now knows a thing. Position — someone now has power they did not. Relationship — the terms between two people have changed. Commitment — someone has decided, and cannot easily undecide.
A scene may turn quietly. The turn does not have to be a revelation or an argument; it can be one person deciding not to say something. What it cannot be is absent, and the most common cause of an absent turn is a scene written to convey information the audience needs rather than to happen to the people in it.
How
- Before writing, name the turn in one sentence: what is different after.
- Assign the charge in and the charge out. If they are equal, either find the turn or cut the scene.
- Write the state of the world before and after in one line each. If the two lines could be swapped without anyone noticing, the scene has not turned.
- Identify the shape — information, position, relationship, or commitment. A turn you cannot classify is usually a mood change.
- Find the exact line or action where the turn happens, and check it is not the last line. A turn on the final beat leaves no room to see its effect.
- If the scene must exist and will not turn, argue for cutting it and see whether anyone can defend it. Most cannot.