Star Wars: A New Hope, or episode IV (or the first one produced) has the biggest happy hollywood ending I can think of (people reportedly stood up and cheered at the movies final moments). What’s more, it is also a prime example of the classic three act structure.
ACT I: Exposition (41 Minutes Long)
The first act begins with the famous scrolling text that acts almost like a prologue and helps with the big exposition (i.e. where are? a galaxy far far away etc.) and then goes straight into some light action in the form of the movies first battle scene. This scene also introduces the characters of Princess Leia and the droids R2-D2 and C3P0. It also serves to introduce the idea that R2 is very important to both sides, the empire and rebellion. After this first scene the movie slows way down as the droids have a little adventure which winds up bringing them to our protagonist for the remainder of the film, Luke Skywalker, whose uncle buys them. Then we get some more exposition, which is after all what the first act is about. R2’s importance is half-revealed when Luke discovers the message that it is carrying (the message bringing up another character: Obi-Wan Kenobi). The droid then runs off, leading Luke to chase it down. At the end of this chase (which using the word chase makes it sound much more exciting than it is) Luke meets Obi-Wan we have the final little bits of exposition (i.e. what happened to Luke’s father, and a little more on the emp/reb conflict) and Obi-Wan offers to take Luke on an adventure as his student in response to the aforementioned message. Luke however, refuses expressing that he has to remain at home for the sake of his responsibilities (he also feels that he can’t influence the outcome of the conflict). The climax of the first act, or the first plot point, comes when Luke, returning to his house, finds out that his family has been murdered by the empire. He then reverses his previous decision and decides to join Obi-Wan. This decision leads those two characters to set off on the adventure and this brings us to...
ACT II: The Adventure and Thickening of Plot (55 Minutes Long)
The first part of Act II is shows a much darker picture of the world (or rather galaxy) in which our story is set, and introduces our final main character in Han Solo, who is decidedly seedier than our other heroes. The group, comprised of Luke, Han (and his sidekick Chewbacca), Obi-Wan, and the two droids, then proceed to fight their way off the planet. Then the Empire, being led by Darth Vader and Tarkin, escalate the scale of their evildoing and proceed to blow up Princess Leia’s home planet while forcing her to watch (this takes place on the Death Star which is also where the majority of the second act takes place). This cements their evilness in the eyes of the audience. Which makes it all the more exciting when our heroes arrive on the scene to rescue her. This is when all of the characters finally come together. The climax of this Act, or the second plot point, comes in the duel between Obi-Wan and Darth Vader. At the end of the duel Obi-Wan lets Vader kill him, cementing Luke’s resolve to help the rebellion and propelling us to...
ACT III: The Climax (28 Minutes Long Including Credits)
The shortest of all the acts, by about half, Act III is has two parts. The first reveals why both sides were so keen on capturing R2 back in act one: he has the schematics for the Death Star inside of him. It also lets our characters reach the ends of their arcs: Luke is a pilot, as he wanted to be in the beginning of the film, Leia is free and back in charge, and Han gets paid, which he insists he the only reason he helped anyone out, and leaves. The second half is the big climactic battle of the film, wherein Luke destroys the Death Star after having been saved by Han who had a change of heart. Then we have a very brief scene’s worth of falling action where our two male leads are rewarded by Leia and everyone cheers and is very happy. It is on this note that the movie ends with a bit of triumphant music and we cut to credits.