War of the worlds

The purpose of this opening film clip is to show the audience what exactly goes on throughout the film, it also tries to get the viewer hooked and wanting to watch more by starting off the film directly with action.

Timing conventions: Most film openings are around 2 minutes long. However major blockbusters may last up to 5 minutes long.
Set the scene: Looks to be present day with all the latest cars and the surroundings, set in possibly America
Introduce the key characters: Tom Cruise - Just a normal civilian which evades from the enemy and is one of the only survivors.
Introduce pre plot or beginning of the narrative: From watching this clip it seems to be an action film.
Key Credits: such as production company, logos and director.
Usually starts with equilibrium: Some robot out of this world rises from the ground and starts destroying people.