Wikipedia:WikiProject Novels/Harry Potter task force/Notability/Differences/PS

The adaptation of the book into the film necessitated the removal of some plotlines, characters, locations and scenes. As the book is fairly short, and the narrative threads are not excessively interwoven, much less alteration was needed than for later Harry Potter books, some of which are several times as long as the first. The most truncated chapters of the novel are those before Harry learns of his magical heritage; the introductory scene following Uncle Vernon to work is cut entirely, as is the majority of the escape from the owl letters. The scene in Madam Malkin's which introduces Draco Malfoy is also cut from the film adaptation.

A few scenes were modified for dramatic or comic effect. While in the book, Harry merely makes the glass of the python cage vanish allowing the snake to escape, the film adds the comic touch of Dudley falling into the snake tank, at which point the glass reappears trapping him inside. Only four of the six protections around the Philosopher's Stone are shown in the film; the unconscious troll and Snape's logic puzzle were removed as they "did not translate as well to screen as Ron and his chess playing". Some of the tasks were also dramatised for the film adaptation: Flitwick's keys pursue Harry through the door when he manages to find the correct one, and the enchanted chess pieces physically destroy captured pieces instead of merely dragging them off the board. Quirrell, instead of tying Harry up in the final chamber, surrounds the room with magical fire to prevent him escaping. Quirrell's pain when touched by Harry is dramatised in the film – each area Harry touches actually turns first to ash, then to stone.

Many minor alterations are present in the film, mainly to simplify subplots and avoid the need for long expository sequences. While the initial part of the Norbert subplot is retained, it is tied off without the involvement of Charlie Weasley. This change had knockon effects removing the midnight duel with Malfoy and the Forbidden Forest detention. A minor alteration that angered devoted fans was the presentation of Dudley and Petunia Dursley as brunette, while they are described as pale blond in the novel. Harry's eyes are also brown in the film rather than green, and Ginny Weasley's are blue rather than brown. These alterations have all been continued in later Harry Potter films.