History Trivia / HarryPotterAndThePrisonerOfAzkaban

** Creator/DanielRadcliffe named this as his favourite book in the series.

** Between having the pre-existing sets from the first two films and the fact that the characters spend a lot more time outdoors in this one, ''Azkaban'' managed to film almost all the Hogwarts interiors at the studio. Parts of Hogwarts that were previously portrayed by real-life locations either go unseen in this film or else are substantially altered. For instance, [[ChaosArchitecture the area of Hogwarts that was previously represented by Alnwick Castle is replaced in this film by the Clock Tower Courtyard]]. However, there is still one real-life location that represents a Hogwarts interior in this movie. The staircase leading to Trelawney's classroom is actually the Geometric Staircase at St Paul's Cathedral.

** Between having the pre-existing sets from the first two films and the fact that the characters spend a lot more time outdoors in this one, ''Azkaban'' managed to film almost all the Hogwarts interiors at the studio. Parts of Hogwarts that were previously portrayed by real-life locations either go unseen in this film or else are substantially altered. For instance, the area of Hogwarts that was previously represented by Alnwick Castle is replaced in this film by the Clock Tower Courtyard. However, there is still one real-life location that represents a Hogwarts interior in this movie. The staircase leading to Trelawney's classroom is actually the Geometric Staircase at St Paul's Cathedral.

** This trope never gets more averted in the series than it is in this movie. Hogwarts is meant to be located in Scotland, but for the most part, the ''Potter'' films were done in England with only background plates shot in Scotland. For ''Azkabban'', however, they actually took the principal cast on location to Scotland, where they filmed the scenes involving Hagrid's Hut at Clachaig Gully in Glencoe. That said, some of the exteriors were still done in England, particularly at Virginia Water in Surrey.
** Between having the pre-existing sets from the first two films and the fact that the characters spend a lot more time outdoors in this one, ''Azkaban'' managed to film almost all the Hogwarts interiors at the studio. However, there is still one real-life location that represents a Hogwarts interior in this movie. The staircase leading to Trelawney's classroom is actually the Geometric Staircase at St Paul's Cathedral.

* MoneyDearBoy: Creator/GaryOldman took the role of Sirius because he had not done a film in over a year and needed the work desperately. This turned out to be a positive version of the trope though as he gave a great performance, became good friends with Creator/DanielRadcliffe while filming, and happily came back for the sequels. Combined with his role as Commissioner Gordon in Film/TheDarkKnightTrilogy, the role served as a CareerResurrection for him.

* WhatCouldHaveBeen: See [[WhatCouldHaveBeen/HarryPotterAndThePrisonerOfAzkaban page]].

* TropeNamer;
** SecretKeeper
*** SecretSecretKeeper

** Creator/DanielRadcliffe had a crush on a girl during filming, and personally requested that he has his sleeping bag placed near hers during the conversation between Dumbledore and Snape.
* SoMyKidsCanWatch:
** Creator/EmmaThompson took the role of Professor Trelawney to impress her daughter.

* BTeamSequel: Creator/ChrisColumbus stepped down as director due to family commitments. He stayed on as producer and then vacated the series.

* CreatorPreferredAdaptation: Creator/JKRowling said this was her favourite of the films, claiming she got goosebumps watching some parts of it. She also mourned the fact that she didn't think of the shrunken head herself while writing the book.

* RomanceOnTheSet: Sort of. At the time of filming Dawn French (the Fat Lady) was married to Lenny Henry, voice of the shrunken head on the Knight Bus.

** This almost happened to Dudley, as Harry Melling had lost a lot of weight in between films. They ended up just putting him in a fat suit.

* DummiedOut: The UsefulNotes/GameBoyAdvance version of the game has remnants of a Butterbeer VideoGame/{{Tapper}} minigame [[https://tcrf.net/Harry_Potter_and_the_Prisoner_of_Azkaban_%28Game_Boy_Advance%29#Unused_Minigame floating about]] in the data. You can cheat your way into it, but it's {{Unwinnable}}, as the "catch the mug" routine was either removed or never finished. [[https://www.neogaf.com/threads/lttp-harry-potter-and-the-chamber-of-secrets-gbc-unmarked-spoilers.1010680/page-2#post-155990317 It was cut at the last minute due to concerns about legal issues.]]

* WhatCouldHaveBeen:
** Creator/AlfonsoCuaron intended for the choir to show tiny people jumping on the keys. Creator/JKRowling vetoed that, claiming tiny people were alien to the HP Universe. He also wanted to put a graveyard in, but she vetoed that as well - claiming it would contradict an important plot point in later books. She did however allow him to place a sundial on the grounds.
** The original script called for Hermione to slap Draco as she does in the book. During a rehearsal, Creator/EmmaWatson actually slapped Creator/TomFelton with full force. She later said she had no idea why she did it, and felt horrible about it afterwards. This is why she punches him instead in the final version (as a punch is easier to fake than a slap).
** Creator/IanMcKellen was asked to play Dumbledore after Richard Harris's death, but he turned it down due to the dislike Harris had always felt in real life towards [=McKellen=] (according to rumors, it all started with ''Film/TheLordOfTheRings'', as Harris had lobbied strongly for the role of Gandalf and came to believe Ian had robbed him). Still, he later said he regretted not having played a role in the franchise.
** Creator/ChristopherLee and Creator/PeterOToole were also considered for Dumbledore, while Creator/RichardAttenborough lobbied for it but was turned down.
** Creator/TildaSwinton was the first choice to play Professor Trelawney.
** Creator/GuillermoDelToro was approached to direct. He opted to work on ''Film/Hellboy2004'' instead, but recommended his friend Alfonso Cuaron, and the rest is history.
** Creator/MNightShyamalan was offered the job of directing the film, but turned it down in favour of ''Film/TheVillage''.
** Alfonso Cuaron wanted the Dementors to be achieved through puppetry. Once it became clear that wouldn't be feasible, he switched to CGI. However, they did use footage of puppets underwater for reference when creating the CGI.
** Although Azkaban doesn't actually appear in the story, concept art of it was created - as a giant stone fortress on the edge of a large waterfall. This design was later used in ''Film/HarryPotterAndTheOrderOfThePhoenix'' when the prison actually appears - though situated on an island in the sea, as in the book.
** Lucius Malfoy would have appeared for Buckbeak's execution scene, but Creator/JasonIsaacs was unavailable.

** According to the recently-published diary of Creator/AlanRickman, he regards the film adaptation as the best and most daring of all the films in the series.

* AuthorsSavingThrow: The AdaptationExpansion for the Time Turner sequence is widely agreed to be a big improvement over how it was handled in the books. The film adds a lot more {{foreshadowing}} for the twist (like having Hermione regularly [[StealthHiBye pop up unexpectedly]] in class) so that it doesn't come out of nowhere, and the PlotTwist [[spoiler: that Harry himself conjures the big Patronus]] is properly set up by showing Future!Harry and Future!Hermione influence other past events too--like throwing pumpkin seeds to warn that Fudge is coming. The film also makes it more clear Time Turners can't actually change the past, but can only establish a StableTimeLoop (which requires ''flawless'' pre-planning to pull off successfully), settling the question of why the characters don't just use Time Turners to undo things like [[spoiler:Cedric Diggory's death]] and [[spoiler:Voldemort's resurrection]].

* CreatorsFavouriteEpisode: Creator/DanielRadcliffe named this as his favourite book in the series.

* DeletedRole: Sir Cadogan, played by Paul Whitehouse, was cut almost completely out of the film.
* DummiedOut: The UsefulNotes/GameBoyAdvance version of the game has remnants of a Butterbeer VideoGame/{{Tapper}}'' minigame [[https://tcrf.net/Harry_Potter_and_the_Prisoner_of_Azkaban_%28Game_Boy_Advance%29#Unused_Minigame floating about]] in the data. You can cheat your way into it, but it's {{Unwinnable}}, as the "catch the mug" routine was either removed or never finished. [[https://www.neogaf.com/threads/lttp-harry-potter-and-the-chamber-of-secrets-gbc-unmarked-spoilers.1010680/page-2#post-155990317 It was cut at the last minute due to concerns about legal issues.]]

* DummiedOut: The GBA version of the game has remnants of a ''VideoGame/{{Tapper}}'' clone [[http://tcrf.net/Harry_Potter_and_the_Prisoner_of_Azkaban_%28Game_Boy_Advance%29#Unused_Minigame floating about]] in the data. You can cheat your way into it, but it's {{Unwinnable}}, as the "catch the mug" routine was either removed or never finished.

** Creator/MichaelGambon replaces the late Creator/RichardHarris. Creator/DawnFrench also replaces Elizabeth Spriggs as the Fat Lady.