Taika Waititi said that while he was already looking for ways to diversify the cast of the film, Tessa Thompson got the Valkyrie part because she simply gave the strongest audition.
In the comics, Hela is 6'6"note 1.98m, but in this movie, she's played by the 5'8"note 1.73mCate Blanchett. However, since Hela is, of course, a literal goddess, it would be hard to find a person (much less an actress, regardless of their performance) who fits this height. Though to be fair, unlike the comics Hela, who like the myth was Loki's daughter and thus her height was due to being part-frost giant, this Hela was Odin's daughter.
Tessa Thompson is billed after Jeff Goldblum despite her character Valkyrie having much more screentime and a far more important role in the story than the Grandmaster. This comes about as the top-billed cast is listed alphabetically sandwiched between Thor stalwarts Hemsworth and Hiddleston and the lucrative And Starring co-stars.
The movie is partly set in the United States but the entirety of principal photography took place at Village Roadshow Studios in Australia, except for the scenes shot in the streets of Brisbane, which coincidentally is standing in for New York.
Reshoots were filmed at Pinewood Studios in Atlanta, GA. The only outside scene you can see from reshoots is the scene where Odin, Thor, and Loki sit down and look out into the ocean. It takes place in Norway but was shot in a field near the studio in Georgia.
After the meeting of Doctor Strange and Thor, Thor looks for Loki, and goes with a key that Dr. Strange gave him. Thor goes near some portable toilets, and when he goes to one, a construction worker comes out of a portable toilet. Thor sees the toilet button which transforms into a lock, and Thor uses the key to open the door. When he opens it, Loki appears, and then tells him "Took you long enough", and Thor responds "I had to pick up the Key". Loki tells him "No one else needed a key", and Thor laughs.
The scene when Odin dies and Hela destroys Mjølnir originally takes place in an alleyway in New York City. In that original scene, Odin doesn't reveal that Hela is his daughter and Hela kills Odin herself by impaling him with a necrosword. Taika Waititi revealed in an interview that Thor would have later find out from Valkyrie that Hela is is sister, but he decided to have the reveal early in the movie because "it's actually not the most important thing. What's more important is the fact that Asgard was built on lies."
When Thor is still captured in the chair and Grandmaster speaks to him, a Bat arrives in the room and passes close to the Grandmaster, and he sends his Guards to go to the other Bats. The Guards begin to chase them, while Thor tries to take out the Obedience Disk.
Guards escort Valkyrie to Hulk's quarters.
While chasing Thor in order to stop him from leaving Sakaar, Hulk is cheered by a few Sakaarans, despite the fact the Hulk is destroying a few vehicles and a Sakaaran's food cart.
While hiding on Sakaar, Banner and Thor had a talk about the Hulk, during which Banner says alternative versions of what Hulk said to Thor and quote a few things that Thor said to Hulk.
When Grandmaster sends Loki and Valkyrie to find Thor and Hulk, he makes a sign with his hands saying to leave, asks Topaz what he understood. He says that there are many universal gestures, then Grandmaster makes a gesture, but Topaz misunderstand it; Grandmaster makes the same gesture several times, but Topaz continues to misunderstand him until Grandmaster tells him that the gesture he made was "Where is my check?" Topaz says the same as Grandmaster, but she does with a different gesture.
While traveling to Asgard, Thor confides in Banner about his Odin's death and his lack of confidence without his hammer note This was before the film's reshoots, as Thor mentions that his father was murdered by Hela, and the film's line about Thor not being "the god of hammers" is said by Banner rather than Odin here. In his attempt at a pep-talk, Banner compares Thor needing Mjølnir to Dumbo needing a magic feather to fly, a reference that Thor doesn't understand.
Hela curses upon watching Loki and the Statesman in Asgard.
An alternate scene parodies this trope. When Skurge was about to cut the head off an Asgardian, Yondu Udonta appears, but then sees the place, and asks if any of those who knew where Kevin and Lou's office was, then someone tells him where he was, then he thanks he, and goes saying that they can proceed, after this, all the present Asgardians began to laugh.
Directed by Cast Member: Taika Waititi both directs the film and plays Korg. He also did the motion capture for Surtur (who is voiced by Clancy Brown), as well as the Hulk in some scenes that needed to be shot after Ruffalo had wrapped filming.
Dueling Works: Due to this film's release the same month as the DC Extended Universe's major Super Team crossover film Justice League. Both feature superheroes teaming up to save a world from a destructive deity who wears a horned helmet and is hell-bent on dominating said world. The difference is that Justice League features well-known superheroes, whereas Thor: Ragnarok features a rag-tag team of heroes who wouldn't normally team up on their own. Both films were also promoted as being Lighter and Softer than their predecessors (Captain America: Civil War in the case of Ragnarok and, well, every preceding DC Cinematic Universe film not titled Wonder Woman in the case of Justice League). In an outcome few would have predicted years earlier, Ragnarok won, earning both significantly higher critical and audience praise as well as stronger box office figures ($853 million vs. $657 million) against a much lower budget ($180 million vs. League's $300 million).
Chris Hemsworth had to significantly bulk back up after playing a slim character in Ghostbusters (2016). Also, he couldn't grow his hair out in time for the production of Ragnarok, so he wore hair extensions for early scenes before the Expository Hairstyle Change.
Karl Urban bulked up and shaved his head to get into character as Skurge even though his body is hidden underneath a suit of armor.
With Doctor Strange's inclusion, some fans are calling the film Thor: Defenders due to Hulk and Strange being two of the founding members of the team and Thor being closely associated with Valkyrie, another prominent member of the team. Alternatively, some people are calling RagnarokAvengers 2.75note Similar to how Captain America: Civil War was a Stealth Sequel to Avengers: Age of Ultron and was referred to as Avengers 2.5 by fans, critics, and Marvel themselves, not only due to the inclusion of these characters but how Word of God confirms that the events of this movie will play a large role in the buildup of Avengers: Infinity War.
God Never Said That: Many have cited Kevin Feige's comments about the film being on par with Captain America: The Winter Soldier as meaning that it would be Darker and Edgier, which was conflicting with director Taika Watiti's comments. However, Feige only said it would be a reinvention of the franchise, using Cap's second outing as an example of such a re-tool succeeding before.
Harpo Does Something Funny: Jeff Goldblum was encouraged by Taika Waititi to improvise and be creative with his portrayal of the Grandmaster in order to make it his own.
As soon as Cate Blanchett's name was first mentioned in the press in conjunction with this film back in December 2015 when it was initially rumored that Marvel was circling her for a role, a subset of the fandom immediately predicted that she was being approached to play Hela. Then Mark Ruffalo let slip that she was indeed in negotiations to play the film's Big Bad and the rumor mill again went into overdrive. The fan speculation was eventually proved true in May 2016 when Marvel confirmed her casting as Hela in an official press release.
After the mid-credits scene in Doctor Strange (2016) a number of fans called that Doctor Strange would be in the film in some capacity. As it happens, not only were they correct, but it ended up that the scene in question was actually a scene from Ragnarok inserted into the credits as a teaser.
After seeing concept art of Infinity War with Thor wielding an axe, many guessed that Mjölnir would get destroyed in Ragnarok.
A number of fans guessed that the blonde-haired warrior who saves Valkyrie in the flashback was her lover, which Tessa Thompson later confirmed in an interview.
A few people guessed that the film would deal with forgotten or otherwise unrevealed offspring of Odin. Especially Angela, whom Hela gets some of her characterization from.
There had been fan speculation that the Infinity Gauntlet seen on Asgard in the first Thor film was a fake all along; Hela confirms it here.
Jossed: Way back in Thor, a fully-assembled Infinity Gauntlet could be seen in Asgard's treasure vaults, leading to many theories about how it would come into play in Avengers: Infinity War. In this film, Hela finds this gauntlet and dismisses it as a fake, providing an I Knew It! to those fans who said it was probably just an Easter Egg placed in Thor before it was decided that the Gauntlet would serve as the overall story arc of the entire MCU.
Milestone Celebration: A minor one, but this film was released in 2017 — the 55th anniversary of the first appearances of both The Mighty Thornote Journey Into Mystery #83 (August 1962)and the Incredible Hulknote The Incredible Hulk #1 (May 1962). In addition, 2017 was the centennial of Jack Kirby, one of the co-creators of both characters (with the film being heavily influenced by Kirby's art). Incidentally, due to the practice of cinemas showing the movie the night before its official American release date, it came out on November 3, 2017, the 90th birthday of Steve Ditko, the co-creator of Doctor Strange. In addition, its release (along with the other 2017-dated MCU films) coincided with the 10th anniversary of the start of production on Iron Man, the first Marvel Cinematic Universe film which was released in 2008 but filmed during 2007; coincidentally, the film includes references to Tony Stark and features the Hulk — the lead character of the second MCU film, also produced during 2007.
The scene showing Loki juggling with knives in slow motion doesn't appear in the movie.
The scene where Hela summons a Storm of Blades during the Bifrost battle doesn't appear either.
The Other Darrin: The Hulk's vocal effects and few bits of dialogue had been provided by Lou Ferrigno in previous MCU films, but starting with this film Mark Ruffalo takes over voicing the Hulk, in addition to playing Bruce Banner.
Chris Hemsworth's brother Luke plays a stage actor playing Thor at Asgard, which doubles as a Development Gag since their brother Liam was originally considered for the role before his older brother was cast.
Two of the women who nurse Thor back to health after the fight against Hulk are played by Taika Waititi's and Chris Hemsworth's wives, Chelsea Winstanley and Elsa Pataky.
One of the girls asking Thor for a selfie in New York City is portrayed by Chris Hemsworth's second cousin, Taylor Hemsworth.
There's a scene where Heimdall saves an Asgardian family of four (father, mother, son, and daughter) from Berserkers in an Asgard forest. The son and daughter of the family are portrayed by real-life brother and sister.
Thor: The Dark World was originally going to feature an appearance from Valkyrie, but the idea ended up being scrapped. Valkyrie would later be used as a major character in this movie. Hela was also planned to be the villain in The Dark World at one point, but was likewise reused for Ragnarok.
The inclusion of "Immigrant Song" by Led Zeppelin was actually originally scripted to happen in Thor, according to that film's co-writer Zack Stentz. It was scripted to appear in scenes whenever Thor rode into battle, but ultimately it was cut.
Sequel Gap: Of a sort. Four years is a perfectly normal gap, but in terms of the MCU lineup, Ragnarok is separated from the previous Thor film by eight movies, when most MCU direct follow-ups are separated from their predecessor by no more than three or four films. In the busier Phase Three, gaps of up to seven films are becoming more commonplace, but the gap between The Dark World and Ragnarok is still the largest gap in the lineup to date.
So My Kids Can Watch: Cate Blanchett has commented that the reason she accepted a role in this movie (and in the MCU) is for the street cred it will give her with her kids. Her eldest son is even the one who suggested she take the role, as he argued it'd be a career boost.
Star-Making Role: While he had already several critically acclaimed films under his belt, Taika Waititi was arguably thrust into the mainstream spotlight with this film (along with his next film), to the point that he was tapped by Disney to help work on the Star Wars franchise.
Cate Blanchett (Hela) and Karl Urban (Skurge) were both in The Lord of the Rings trilogy as Galadriel and Éomer respectively. Urban commented that one of the main reasons he wanted to play Skurge was to work directly with Blanchett, whom he didn't get to share a scene with in LOTR.
Skurge is completely absent from Hasbro's product line for the movie, despite Thor, Hela, the Hulk, Valkyrie and Loki all being prominently featured. He doesn't appear in any of the Lego kits either. However, he does appear in Funko's Mystery Mini line.
In some interviews, Taika Waititi said that he ignored the other Thor movies, sometimes even claiming that he didn't even watch them. Given the many Call Backs and Continuity Nods to both Thor and Avengers movies this was obviously not to be taken seriously.
Taika Waititi begins the director's commentary by stating that he doesn't like director's commentaries, and then proceeds to spend the entire time proving it by alternating between riffing on the scenes and making up fake 'facts' about production such as having actually been on fire while performing motion capture for Surtur.