One of the most important things about making a great fantasy/sci-fi film is the creation of the world. That's why HARRY POTTER is so great. The world is rich and borrows a lot from various Greek myths and wizard and witch tales, but finds a way to make it feel refreshingly original.
The story begins with young Harry Potter (Daniel Radcliffe) living under the stairs of his mean aunt and uncle's house. On a visit to the zoo, we learn that Harry has strange abilities that he does not understand. Then the owls arrive, carrying letters inviting Harry to come study at Hogwarts School of Witchcraft and Wizardry. However, his uncle Vernon (Richard Griffiths, WITHNAIL & I) wants nothing to do with all this embarrassing witches and wizards hoopla. So the family runs to the countryside, but they can't hide from magic — arriving for Harry is the kind giant Hagrid (Robbie Coltrane, FROM HELL), who takes Harry into a marvelous world that exists in the shadows of the human world.