Narration and storyline are keys components in a film which make up the baseline of a movie. Usually the audience are expected to watch due to a good narrative; almost like conventions whereby the important factors within that genre should be incorporated into a film e.g. in action films explosions, guns and violence is the main theme. However, it is know in some films that the storyline is too confusing or doesn't make sense (take Inception for example) which is also why it is important to explain clearly what the aim of the topic is in the film, so the audience don't get bored.
Some film's storyline seem a bit monotonous, as if it had been done before; sometimes it is just a variation on a theme. The problem here could be that big blockbuster movies mean cheap budget films don't have new ideas, because they are made up from elements the "bigger" film already has. In addition, if a plot is to be made into a film, the rise in action should take place relatively near to the beginning, so that the atmosphere/tension is created instantly, thus allowing it to slowly evolve, otherwise eventually the viewer will become inattentive.
A storyline usually starts at equilibrium where everything Is normal, before chaos happens and creates a state of unbalance. At the middle/centre of the film, there is disequbilirum, before there is a resolution or answer to the problem. Before ending a state of new equilibrium is created. This is Tvetan Todorav's theory of narrative within a film, and is associated to a majority of movies, however more recently there is a factor effecting this, which is ending on a cliff-hanger; some horror films (paranormal) are related to this, typically done to create an opening for a sequel.
Finally, it is also the characters in a film, which develop the storyline; their actions may lead to consequences and create the start of narrative expansion. People in films are usually the reason for the outbreak of a tragedy, for example in the majority of zombie films, the infection usually spreads due to a lack of security or clumsiness within a facility or key setting. The base of a story is commonly created via Binary oppositions (good vs. evil, man vs. alien etc.) therefore without this, there is no plot, and thus no progression in the film; it is rather pointless and leads to a non conclusive end.
Levi Strauss - Binary Oppositions (Good vs. Evil)
Vladmir Prop - 7 Spheres of Action (structural features to a character e.g. a hero restores equilibrium, whilst a villain disrupts it
Tvetan Todorav - 3 stages of narrative (equilibrium, state of disequilibrium, state of new equilibrium)
Barthes - Narrative Codes (Visual codes, similar to an enigma's)