How to create action in a screenplay

A film script isn't built the way children write stories - event after event.
That's a recipe for dullness. Unfortunately, many books are written like that.

A screenplay must consist of actions, meaning events connected by cause and effect.

Example of action:

A fox goes for a walk and finds honeycombs. He's surprised. A bear appears - it's his honey! He thinks the fox wants to steal it and chases him. The fox escapes into a hollow tree but sprains his paw - setting up the next scene. Now he can't move freely, and if the bear finds him?

That's a chain of events, where each event results from the previous one.

The price of victory and the taste of defeat - controlling value

In life, anything valuable comes at a cost.
You must fight for it, pay a price for success or even for trying.

Example:

The bear manages to get the honey but is chased and stung by mutant bees with powerful venom. He escapes, but at the cost of a broken paw - and loses the honey. So he can escape and win something but must pay a price. He can also lose and still pay dearly. Whenever something is valuable, there must be guardians protecting it fiercely.

 Raising the stakes

When creating action, remember the stakes - what's at risk. Don't start with the highest stakes. In the exposition, introduce a strong reason for the hero to begin their journey.
Then let the stakes rise gradually, peaking at the climax.

Example:
When the bear thinks he's safe, it turns out the mutant bees are smarter than expected - now they're hunting him to eliminate the threat.