The first of the Harry Potter films broken into acts to show the structure.
Harry Potter is a phenomenon. J.K.Rowling's schoolboy wizard battling the dark forces of evil while trying to deal with childhood angst has become a remarkable creative and financial success. Of all of the recent book series that have been turned into films the Harry Potter films are, by far, the most successful, the most satisfying and the best written, something that derives extensively from the quality of the original tales.
All the Harry Potter books are classic heroic legends, filled with heroes and villains, complex motivations that drive essential themes and the ability of people to put aside petty squabbles to unite against truly despicable forces. They are among the most complete children's books ever written and have been adapted for film in a very satisfying way. We're going to look at the first of the Harry Potter films here, because it's a film that almost everyone has seen and its themes are accessible and well-structured. In short, it is a very good example of how to write a good screenplay.
We meet Dumbledore, a great wizard and McGonagall, an ally. They discuss some major event with positive and negative consequences. Hagrid, a giant, appears on a flying motorcycle to deliver an infant, Harry, to the wizards. They leave the infant on the doorstep of his only living relatives, his Aunt and Uncle. Dumbledore defends this because Harry will be famous in their world, so it will be better for him to be raised in a normal environment.
Years later Harry is living with his relatives still, the Dursleys. They have a spoiled son, Dudley, a little older than Harry, but they treat Harry very neglectfully, he lives in a locked cupboard under the stairs and is ignored. A trip to the zoo is organised to celebrate Dudley's birthday and during the trip strange things seem to happen. Harry is blamed, but he can't see why.
Harry's 11th birthday isn't celebrated at the Dursley house. He does, however, receive an old-fashioned-looking letter. The Dursleys steal it and destroy it, to prevent Harry from seing its contents.
The following day Harry receives several identical letters, also destroyed by the Dursleys, the day after more come. Harry's Uncle seals up the letterbox but that leads to hundreds of letters pouring in through the fireplace. The Dursleys decide to abandon their home and travel to a remote stone cottage on an island in a lake, seemingly just to avoid Harry seeing the content of his letters.
That night Hagrid visits the cottage, destroying the door when it isn't opened for him. He delivers a birthday cake to Harry, along with a copy of the letter, informing Harry he's going to go to Hogwarts School of Witchcraft and Wizardry, since he's a wizard like his parents before him. Harry has no idea of any of this. When it becomes clear that the Dursley's hid Harry's heritage from him Hagrid becomes angry, but when he finds out they told him his parents died in a car accident Hagrid is furious. Harry's parents were murdered by the dark wizard Lord Voldemort who also tried to kill Harry. For some reason Harry lived, Voldemort was destroyed and Harry is therefore the boy who lived and a celebrity in the wizarding world.
Hagrid takes Harry to a magical street, Diagon Alley, to shop for his school supplies, once done Harry boards a magical train to Hogwarts. On the train he meets Ron Weasley, a member of a large and warmly eccentric family of wizards, and Hermione Grainger, the daughter of two non-magical (muggle) parents. Ron will prove to be Harry's guide to the wizarding world, having grown up in it. Academically brilliant Hermione will help Harry with his magical studies. Harry also encounters a smooth-talking bigot, Malfoy, who has been raised to believe in purity in the wizarding community, that only children of two magical parents should be trained as wizards. He and Harry dislike each other instantly.
Arriving at school the new students are sorted into houses, Harry, Hermione and Ron all end up in Griffindor. Harry learns that most dark wizards come through Slytherin house. Harry is recruited to Griffindor's Quidditch team, a magical sport, and learns his father played as well. Griffindor's house teacher is McGonagall and Harry immediately dislikes the Slytherin house teacher, Snape. Hogwarts is a very traditional British public school, completely familiar to anyone educated privately in the UK.
One night the three friends discover a giant three-headed dog (a nod to Cerberus) in the school. They learn that the dog is guarding The Philosopher's Stone, a magical artefact with the ability to restore life and prolong it indefinitely. In their unauthorised wanderings they are caught and given a detention, which they serve helping Hagrid look for an injured Unicorn in the Forbidden Forest. While there Harry sees a spectre of some sort drinking the blood of the lost unicorn, and learns that its blood, too, can prolong life. The children become convinced that Snape is trying to steal the Stone and restore life to someone, possibly Voldemort, since Harry thinks he wasn't completely destroyed. Hagrid tells them that it's impossible, Snape is one of a number of teachers who have placed magical traps protecting the stone.
Hagrid accidentally reveals the dog is his own trap and how to get past it, also letting slip that someone else knows this secret. THe children try to warn Dumbledore but he's left the school, so they become convinced Snape will strike that night in Dumbledore's absence. They decide to go after the stone themselves to try to prevent Snape from gaining it.
Our heroes start battling through the traps, it quickly becomes clear they aren't the first ones through. One by one they defeat the traps and make their way to the final chamber, though Ron and Hermione have to be left behind and only Harry reaches the final goal.
Harry discovers the thief is, unexpectedly, Quirrell, another teacher, not Snape. Quirrell is stumped by the last test, set by Dumbledore, but Harry can complete it and does so. Quirrell reveals that Voldemort isn't completely dead, as we suspected, and is in fact living in Quirrell, using him as life support. It was the Quirrell / Voldemort entity that killed the unicorns and wants the Stone to restore Voldemort to full life.
Harry battles Quirrel and eventually defeats him with the touch of his hand. Voldemort's spirit flees, but is still alive, ish.
Harry, now victorious and in bed, learns a few crucial things from Dumbledore. Voldemort was originally defeated by Harry's mother's sacrifice in throwing herself between Voldemort and her infant son. That act of love and devotion was what protected Harry from Voldemort and what still protected him from Quirrell recently. The children are reunited, there are awards all round and the story ends with Harry deciding the wizarding world is actually his real home, not the suburban Dursleys.
Compare the first and third acts to Star Wars. Orphan boy, raised by relatives, pulled away from them by external circumstance, driven to explore the heritage of his parents, it's a fairly classic hero's origin. At the end, final battle, relying on friends and skills developed in the second act, victory against tough odds and in a way that only Harry was really able to achieve, followed by celebrations and medals.
Harry has proven himself a real hero, even more so than Dumbledore, who people treat with enormous respect as a powerful and good wizard, and the one man Voldemort always feared. Ron and Hermione are, of course, entirely peripheral, adding character and depth to Harry but never acting independently. When all the good adults are clearly Dumbledore's people, Ron and Hermione are Harry's people. Harry's big personal growth is not only in learning the magic he needs to win in act 3 but also learning to be a leader, something that will be a recurring theme in seven further films.