History Trivia / ReadyPlayerOne2018

** Before his untimely death Creator/GeneWilder was offered the role of James Halliday, but he politely declined. Creator/MichaelKeaton was also considered.

** Avoided with Sonic the Hedgehog, who makes a cameo appearance in the final film. Since Creator/{{Paramount}} was making a [[Film/SonicTheHedgehog2020 feature film]] adaptation at the time, Warner Bros. met up with Sega and Paramount to work out a deal that kept him in the movie, an arrangement similar to what Creator/{{Disney}} did with the two in regards to both Sonic and Dr. Eggman's appearances in ''Disney/RalphBreaksTheInternet''.

* SwanSong: In the Japanese dub, this was one of the final voice acting works Tetsuo Goto (as James Halliday) did before dying at November 2018.[[note]]Technically speaking, his final voice acting work was the Japanese dub of ''ComicBook/MortadeloYFilemon'' live-action film as El Super, according to Yōhei Tadano, Mortadelo's Japanese voice actor.[[/note]]

** Creator/JackNicholson was [[https://variety.com/2019/scene/news/doctor-sleep-the-shining-cameo-danny-lloyd-1203388429/ approached]] to make an appearance in the film, possibly reprising his legendary role as Jack Torrance. However, Nicholson declined the offer as he is retired since ''Film/HowDoYouKnow''.

** The first draft of the screenplay involved Wade going through a recreation of ''Film/BladeRunner'' as the second challenge before it was changed to a reenactment of ''Film/TheShining''. Interestingly enough, Creator/WarnerBros holds the rights to both films.

* FakeAmerican: Olivia Cooke (Samantha / [[spoiler:[=Art3mis=]]]), Creator/SimonPegg (Og), Creator/MarkRylance (Halliday) and Creator/HannahJohnKamen (Zandor) are British, Creator/BenMendelsohn (Sorrento) is Australian.

** Avoided with Sonic the Hedgehog, who makes a cameo appearance in the final film. Since Creator/{{Paramount}} was making a [[Film/SonicTheHedgehog2020 feature film]] adaptation at the time, Warner Bros. met up with Sega and Paramount to work out a deal that kept him in the movie.

* ScrewedByTheLawyers: Even though Cline's original novel prominently featured [[Franchise/UltraSeries Ultraman]] fighting [[Franchise/{{Godzilla}} Mechagodzilla]], Creator/WarnerBros replaced the character with the titular protagonist of ''WesternAnimation/TheIronGiant'' due to the then-ongoing legal dispute between Creator/TsuburayaProductions and Chaiyo Productions over who owned the rights to the character. [[spoiler: Mechagodzilla managed to make it into the movie for the climatic final battle.]] To twist the knife further, Tsuburaya and Chaiyo finally resolved the issue, during the first week of the film's release in theaters.

* MultipleLanguagesSameVoiceActor: In the Japanese dub, Win Morisaki reprise his role as Daito. Oddly enough and despite his Japanese name, he is Burmese.

* ActingForTwo: All of the actors playing the main characters also provide the voices for their avatars. In the case of Aech and Sho, voice filters were used for their avatars to disguise their real voices.

** The film's score was originally going to be composed by Music/JohnWilliams but due to scheduling conflicts, he left and was replaced with Music/AlanSilvestri. Hilariously, this means a unexpected reunion occurs of Steven Spielberg, Alan Silvestri and [[Film/BackToTheFuture a certain Delorean...]]

* ActingForTwo: All of the main characters' avatars have the same actors as their users. In the case of Aech and Sho, voice filters were used for their avatars to disguise their real voices.

* ScrewedByTheLawyers: Even though Cline's original novel prominently featured [[Franchise/UltraSeries Ultraman]] fighting [[Franchise/{{Godzilla}} Mechagodzilla]], Creator/WarnerBros replaced the character with the titular protagonist of ''WesternAnimation/TheIronGiant'' due to the then-ongoing legal dispute between Creator/TsuburayaProductions and Chaiyo Productions over who owned the rights to the character. [[spoiler: Mechagodzilla managed to make it into the movie for the climatic final battle.]] To twist the knife further, Tsubuyara and Chaiyo finally resolved the issue, during the first week of the film's release in theaters.

** The first draft of the screenplay involved Wade going through a recreation of ''Film/BladeRunner'' as the second challenge before it was changed to a reenactment of ''Film/TheShining''. Interestingly enough, both films are currently owned by Creator/WarnerBros.

** The first draft of the screenplay involved Wade going through a recreation of ''Film/BladeRunner'' as the second challenge before it was changed to a reenactment of ''Film/TheShining''.

* ScrewedByTheLawyers: Even though Cline's original novel prominently featured ''Franchise/{{Ultraman}}'' fighting [[Franchise/{{Godzilla}} Mechagodzilla]], Creator/WarnerBros replaced the character with the titular protagonist of ''WesternAnimation/TheIronGiant'' due to the then-ongoing legal dispute between Creator/TsuburayaProductions and Chaiyo Productions over who owned the rights to the character. [[spoiler: Mechagodzilla managed to make it into the movie for the climatic final battle.]] To twist the knife further, Tsubuyara and Chaiyo finally resolved the issue, during the first week of the film's release in theaters.

* ScrewedByTheLawyers: Even though Cline's original novel prominently featured ''Franchise/{{Ultraman}}'' fighting [[Franchise/Godzilla Mechagodzilla]], Creator/WarnerBros replaced the character with the titular protagonist of ''WesternAnimation/TheIronGiant'' due to the then-ongoing legal dispute between Creator/TsuburayaProductions and Chaiyo Productions over who owned the rights to the character. [[spoiler: Mechagodzilla managed to make it into the movie for the climatic final battle.]] To twist the knife further, Tsubuyara and Chaiyo finally resolved the issue, during the first week of the film's release in theaters.

* ActingForTwo: All of the main characters' avatars are portrayed by their users.

* ScrewedByTheLawyers: Even though Cline's original novel prominently featured ''Franchise/{{Ultraman}}'' fighting Mechagodzilla, Creator/WarnerBros replaced the character with the titular protagonist of ''WesternAnimation/TheIronGiant'' due to the then-ongoing legal dispute between Creator/TsuburayaProductions and Chaiyo Productions over who owned the rights to the character. [[spoiler: Mechagodzilla managed to make it into the movie for the climatic final battle.]] To twist the knife further, Tsubuyara and Chaiyo finally resolved the issue, during the first week of the film's release in theaters.

* SwanSong: In the Japanese dub, this was one of the final voice acting works Tetsuo Goto (as James Halliday) did before dying at November 2018.[[note]]Technically speaking, his final voice acting work was the Japanese dub of ''ComicBook/MortadeloYFilemon'' live-action film as El Super, according with Yohei Tadano, Mortadelo's Japanese voice actor.[[/note]]

* AuthorExistenceFailure: In the Japanese dub, this was one of the final voice acting works Tetsuo Goto (as James Halliday) did before dying at November 2018.[[note]]Technically speaking, his final voice acting work was the Japanese dub of ''ComicBook/MortadeloYFilemon'' live-action film as El Super, according with Yohei Tadano, Mortadelo's Japanese voice actor.[[/note]]

* AuthorExistenceFailure: In the Japanese dub, this was the final voice acting work Tetsuo Goto (as James Halliday) did before dying at November 2018.

* ScrewedByTheLawyers: Even though Cline's original novel prominently featured ''Franchise/{{Ultraman}}'' fighting Mechagodzilla, Creator/WarnerBros replaced the character with the titular protagonist of ''WesternAnimation/TheIronGiant'' due to the then-ongoing legal dispute between Creator/TsuburayaProductions and Chaiyo Productions over who owned the rights to the character. [[spoiler: Mechagodzilla managed to make it into the movie for the climatic final battle.]]
** Even more of a knife twist, the companies who were trying to figure out who owned Ultraman's film rights finally resolved the issue, during the first week of the film's release in theaters.

** Spielberg decided against featuring references to any of his own films, though luckily this doesn't extend to his producing other directors' work like ''Back to the Future''. Despite that, a number of VFX artists at Industrial Light & Magic were determined to sneak in as many references as they can and hope Spielberg didn't catch all of them.

* UrbanLegendOfZelda: Given the positively immense amount of cameos and references contained in the film, needless to say, rumors that certain characters or objects can be spotted in the movie at one or more points in the movie have gone flying. One of the most persistent rumors is that you can spot ''Website/{{Homestuck}}'' or ''VideoGame/{{Undertale}}'' characters (specifically fan-favorite Sans in the latter case) during the climax.

* CastingGag:
** In the Japanese dub, Creator/YoshitsuguMatsuoka (Shoto) got stuck in [[LightNovel/SwordArtOnline yet another]] [[LightNovel/NoGameNoLife online game]]. The same goes for Creator/AiKayano (F'Nale Zandor) and Creator/KoichiYamadera (Morrow), at least regarding ''LightNovel/SwordArtOnline'' in Yamadera's case.
** The same goes with the same dub with Creator/MaayaSakamoto as Samantha, albeit with a [[Franchise/DotHack very different franchise]].
** The Latin-American Spanish dub also brings back a few cast members from ''LightNovel/SwordArtOnline'', albeit in different roles. Jocelyn Robles (Lisbeth's voice actress) voices Helen and Kerygma Flores (the LA voice for Sakuya) voices Alice. Alejandra Delint (Asuna) plays the red-haired IOI employee.

* MissingTrailerScene: In the book, Wade must defeat an opponent in the arcade game "Joust" - and one of the trailers shows players riding winged creatures in what appears to be live-action Joust. This sequence doesn't appear in the film, though a ''Joust'' character does appear in the final battle.
** Technically, the scene does still appear in the film, as we see a whole army of them going against the scorpion mechs just moments before being introduced to Aech on Planet Doom. The thing that's missing is the shot of a Napoleon avatar holding Excalibur above his head, riding on the back of a scorpion mech as it grabs an Joust ostrich and reverts it back into an egg, as seen in the San Diego Comic Con teaser trailer.