The three act structure

In Hollywood film narrative tends to be organised in what is called "Three act Structure".

In this structure a film must be set up within the first 20-30 minutes before the main character or protagonist experiences a 'Plot point' That gives him or her a goal that needs to be achieved.

Approximately half of the movie must then be taken up with characters struggling to  his or her goal, this is the 'Confrontation' period.

The final quarter of the film despite the climatic struggle by the protagonist to finally achieve his/her goal and the after math of this struggle.