Alan Rickman was hand-picked to play Snape by J.K. Rowling, and received special instruction from her as to his character. Rowling even provided the actor with vital details of Snape's back story not revealed until the final novel.
Warner Bros. originally considered making the entire "Harry Potter" series as a set of CGI animated films, or attempting to combine several of the novels into a single movie. The studio's reasoning mainly had to do with concern over the rapid aging of child actors-if production ran too long on any of the films, or if production was delayed between sequels, the leading actors might have to be recast. Author J.K. Rowling vetoed both the ideas of combining books and an animated film, so the studio decided instead to produce all seven (later eight) films back to back so the same child actors could play their roles in every film.
West Anglia Great Northern Trains, the company that owns "Platform 9-3/4", affixed one-quarter of a luggage trolley forwardly "disappearing" into the wall so as to allow fans (and their parents) to take pictures of themselves seeming to disappear into the wall.
The Restricted Section scene was filmed in the Duke Humfrey's building at the Bodleian Library in Oxford. They have very strict rules about not bringing flames into the library. The makers of Harry Potter were the first ever to be allowed to break this rule in hundreds of years.
Platform 9 3/4 was filmed at King's Cross, but on platforms 4 and 5. J.K. Rowling has admitted that she mixed up the layout of London's King's Cross railway station when she assigned the Hogwarts Express to platform 9 3/4, reached by using magic between platforms 9 and 10. She meant the location to be in the inter-city part of the station, but 9 and 10 are actually among the rather less grand suburban platforms. The movie conformed to the book: the platforms seen as 9 and 10 are in real life inter-city platforms 4 and 5. However, there is, in fact a "Platform 9 3/4" at King's Cross. It's located in the walkway area between the real platforms 9 and 10, as a treat for fans of Harry Potter.
The filmmakers attempted to go the extra mile of matching the kid's appearances to how the novel describes them, by fitting Daniel Radcliffe (Harry Potter) with green-colored contact lenses, and similarly make Emma Watson (Hermione Granger) wear fake buck teeth. But when Dan's eyes reacted strongly to the contacts, and Emma couldn't talk clearly with the fake teeth in her mouth, these ideas were dropped.
The filmmakers originally wanted to use Canterbury Cathedral as a filming location for some of the Hogwarts scenes, but the Dean of Canterbury refused to allow it, saying that it was unfitting for a Christian church to be used to promote pagan imagery. Gloucester Cathedral agreed to take its place; the Dean of Gloucester, the Very Reverend Nicholas Bury, admitted to being a fan of the books. Nonetheless there was a huge media outcry in Gloucester when it was decided to use the local Cathedral as a filming location. Protesters wrote letters by the sack-load to local newspapers, claiming it was blasphemy and promising to block the film-crew's access. In the end, only one protester turned up.
Tom Felton did not read any of the Harry Potter books before auditioning, and at the audition the director was asking each contender for the role of Malfoy what their favorite part in the book was. When it was his turn, Felton said his favorite part in the book was the part at Gringrotts, which is what the previous contender had just said. The director saw through this very quickly and thought it was very funny.
Nicolas Flamel, mentioned as the creator of the Philosopher's/Sorcerer's Stone, has figured as a plot device in novels featuring characters such as Batman, Indiana Jones, and Robert Langdon of The Da Vinci Code (2006). He was (possibly) a real alchemist (born in France around 1330) who was believed by some people to have produced the Philosopher's Stone. Since there were mysterious circumstances surrounding his death in 1418, it has been rumored that he lived for hundreds of years. The book/movie gets his age right.
The movie is known as "Harry Potter and the Philosopher's Stone" everywhere except the USA and so every scene in which the Philosopher's Stone was mentioned was filmed twice (once with the actors saying "Philosopher's" and once with the actors saying "Sorcerer's") or redubbed (notably, one of the times Hermoine says it in the library, her face isn't shown). The reason for this was to keep the films consistent with the book series: the US publisher, Scholastic, had changed the title (and corresponding text) to "Sorcerer's Stone". The title change was done with the consent of author 'J.K. Rowling', but she has since said that she regrets having granting permission, and as a fledgling author she wasn't in a strong enough position to fight it at the time.
In the film, the scar on Harry's forehead is off-center. This was done at J.K. Rowling's request. Due to the artwork on the covers of her books, many people have assumed that his scar is supposed to be in the center of his forehead. The books, however, never specify exactly where on his forehead the scar is located.
The scenes at Hagrid's Hut were filmed on location, albeit in a small patch of land in London not far from Leavesden Studios. The hut was demolished when the shoot wrapped in case fans of the film swamped it.
In the second book of the series, "Nearly Headless" Nick invites Harry to his "deathday" party, celebrating the 500th anniversary of his demise in 1492 (a fact that fans have used to place the entire book chronology in the years 1991-1998). 1492, is, of course, the year that Christopher Columbus made his famous voyage to the New World; this film's production company is "1492 Pictures", a deliberate reference to director Chris Columbus' famous namesake.
At the time this film was in production, only four of the eventual seven books in the series had been published. J.K. Rowling was retained as a consultant on the film, not only to ensure consistency with the first book, but also to avoid conflicts with her vision for the later entries. It has been confirmed that at least one line of dialogue was removed from the script to avoid a contradiction with the then-unpublished "Harry Potter and the Order of the Phoenix".
In this film, all the food that you see in the Great Hall feasts are real. Director Chris Columbus wanted a very elaborate welcome feast to match the description in the book, with roast beef, ham, turkey, and all the trimmings. Unfortunately filming under the hot stage lighting for hours at a time quickly caused the food to develop an unpleasant odor, despite the meat being changed every two days and the vegetables twice a day. For the following films samples of real food were frozen so that molds could be made of them and copies cast in resin.
Author J.K. Rowling insisted that the principal cast be British and she got her wish, with two main exceptions - Richard Harris was, of course, Irish, and Zoë Wanamaker, though she has made her name as a "British" actress, was actually born American in the United States. Other non-Brits in the cast include Verne Troyer, born in Michigan, USA, who plays Griphook, but he's dubbed by a Brit; and Chris Columbus daughter, Eleanor Columbus, who played Susan Bones, and she never says a word. It's also been noted that Emma Watson was born in France, but to British parents, so that doesn't really count.
In the trophy cupboard, to the right of the Quidditch trophy, you can see the "Service to the School" trophy with part of "Tom M. Riddle" engraved on it; the trophy and the name on it are confirmed by Ron in a deleted scene from Harry Potter and the Chamber of Secrets (2002).
In order to give Hogwarts Castle an authentic look and feel, much of the filming was done at locations around England, including Christ Church, Oxford, Durham Cathedral, Gloucester Cathedral, and Alnwick Castle. In fact, the only sets that were built for Hogwarts were the Great Hall, the Grand Staircase, and the Gryffindor Common Room. In the later films, additional sets would be built for the various classrooms and other locations around Hogwarts.
The floating candles in the Great Hall were created using candle-shaped holders containing oil and burning wicks and suspended from wires that moved up and down on a special effects rig to create the impression that they were floating. Eventually one of the wires snapped due to the heat of the flame causing the candle to fall to the floor. Fortunately no one was injured, but the decision was made to re-create the candles using CGI for the following films as using real candles was determined to be a safety hazard.
Richard Harris only agreed to taking the part of Albus Dumbledore after his eleven-year-old granddaughter threatened never to speak to him again. Patrick McGoohan was originally offered the role but had turned it down due to health reasons. Ironically, Harris had health issues of his own, dying of Hodgkin's lymphoma shortly before the release of Harry Potter and the Chamber of Secrets (2002).
Director Chris Columbus has stated in interviews that he is unhappy with the visual effects in this film, saying that they were "rushed" and "never up to anyone's standards," and sought to improve them for the following film. This did not, however, prevent the film from being nominated for a BAFTA award for "Best Visual Effects."
The Wizard's chess-set Harry and Ron were playing in the Great Hall is based on the Lewis Chessmen, which date from the 12th Century. They were found in 1831 on a beach on the Isle of Lewis, Outer Hebrides, Scotland. In all, 93 pieces were recovered, with 11 now residing at the National Museum of Scotland in Edinburgh and 82 at the British Museum in London.
On the Quidditch trophy that has Harry's father's name on it, there are additional inscriptions for M. McGonagall and R.J.H. King. The latter being a reference to John King, the supervising art director on the film.
The trouble-making poltergeist Peeves (played by Rik Mayall) does not, in the end, appear in the movie nor in deleted scenes on any home editions of the film. Mayall claimed he didn't find out that he was cut from the final cut until he saw the movie himself. Ultimately Peeves was never used in any of the Harry Potter films.
Ron's choice of opening in the final chess match is called Center Counter Opening (or Scandinavian Defense), which, due to its asymmetrical nature, is said to be a highly unpredictable and difficult opening for either side, that rarely results in a draw.
The floor in the great hall is made of actual York stone. Production designer Stuart Craig had the foresight to invest a significant amount of his design budget on the stone. While this decision was questioned at the time, it proved to be a wise one, as the stone was durable enough to withstand the footsteps of hundreds of actors and several camera crews over the near decade it took to film the entire series.
Julie Walters has said that had she known that fellow Midlander Mark Williams would be cast as Molly Weasley's husband Arthur in the following film, she would have played up their shared accent, feeling this would have helped signpost their family's perceived uniqueness in the magical world.
When holding auditions for the role of Hermione, the casting team traveled around to local British elementary schools to hold auditions in hope to find their actress. When they arrived at Emma Watson's school, she had no desire to audition despite nearly every single girl in her school wanting to. It was encouragement from her teacher to at least attempt the audition that made her be the last girl to audition of her whole school.
Harry Potter's birthday is stated in the books to be 31 July 1980, as author J.K. Rowling was born on 31 July 1965. By coincidence, actor Richard Griffiths (Uncle Vernon) was born on 31 July 1947. Actor Daniel Radcliffe (Harry Potter) was once reported to been born on 31 July 1989, but this was merely a publicity stunt. In fact, Radcliffe was born on 23 July 1989.
Tim Roth was a leading contender for the role of Professor Severus Snape. Roth dropped out of contention, however, to pursue his role as General Thade in Tim Burton's adaptation of Planet of the Apes (2001).
At one point, Harry mentions that during his trip to London, he heard Hagrid profess his love for dragons and his desire to own one. The scene that Harry describes was filmed but deleted from the movie.
James Phelps and Oliver Phelps, the twin actors who play Fred and George Weasley respectively, both have naturally dark brown hair which was dyed red for their roles. Similarly, Tom Felton's hair, which is also naturally brown, was bleached blond for his role of Draco Malfoy.
In the flying lesson the whistle 'Madame Hooch' is wearing is called a 'Boatswain's Call' and was originally used in the early Navy (before PA systems) to signal an order, because the whistle could be heard from one end of the ship to the other. It is now used in the Navy as a ceremonial whistle.
This movie, the first in the 'Harry Potter' franchise, has the equal highest number of Academy Award nominations by a 'Harry Potter' movie totaling to three. The other series entry to do this was the final film in the franchise, Harry Potter and the Deathly Hallows: Part 2 (2011). This is the only 'Harry Potter' movie to be Oscar nominated for the Best Costume Academy Award.
When filming the scenes at Gloucester Cathedral, the cathedral's modern electric signs, light switches, and door locks had to be concealed behind panels that were painted to match the rest of the stone walls. The stained glass windows were also modified to hide the fact that the building was a church; the religious symbols were covered with colored plastic filter paper to blend in with the surrounding glass. One window depicted the naked figures of Adam and Eve; they were given clothes and even the trademark Harry Potter lightning scars on their foreheads.
The exterior used for King's Cross Station is actually St Pancras Station which is just down the road. This was used because the facade of St Pancras is more visually appealing than that of King's Cross.
All the cars in Privet Drive are Vauxhalls, no matter the time period. The Dursleys own a silver 2000 Vauxhall Vectra estate. All other cars parked in the drives are Vectra estates in the present day, with Astra Belmont and Cavalier saloons from the late 1980s in the pre-titles prologue.
John Williams composed a piece of music specifically for the movie's trailer without having seen a single frame of film, and it is found on the soundtrack as "The Prologue". As of March 2002, he has done this only once before, for Steven Spielberg's Hook (1991). (However, on the collector's edition of the soundtrack for Jaws (1975), a previously unreleased track appears called "Shark Attack" - this was only used in the trailer for that movie - in 1975.)
In the scene where Harry, Ron and Hermione are approaching Hagrid's hut and Hagrid is diverting himself by playing a recorder on his front steps, the song that he is playing is the recurring series motif.
Director Chris Columbus wanted to work with DP John Seale and asked the studio to hire him to shoot the picture, but at that time Seale was committed to shooting Timeline (2003). However, production delays for the latter film enabled Seale to be available for the movie's photography period.
Almost all the scenes with Harry and/or the trio were filmed in chronological order, most notable exceptions being: The final scene in the film where the trio return home on the Hogwarts Express was the first scene filmed, followed by the scene when Harry first sees the locomotive at Platform 9 & 3/4 (the only other scene which required the actual train present). Then, the Quidditch match was the last thing filmed, mostly due to how long it took the effects departments to figure out how to do it.
Originally Daniel Radcliffe was supposed to wear colored contact lenses to turn his naturally blue eyes green (as Harry is described in the books as having green eyes) but after suffering an allergic reaction to the lenses the decision was made to drop them, and Harry's eyes remained blue for the rest of the series. Similarly, Emma Watson was originally going to wear fake teeth (as Hermione is described as having large front teeth) but she couldn't talk clearly with them in, and the teeth were dropped. There is one scene in the film in which Radcliffe and Watson are wearing their respective contact lenses and teeth; it is the final scene in the film where the trio return home on the Hogwarts Express, which actually was the first scene that was filmed.