Asked how many wizards there are, Gandalf says there are five, naming himself, Saruman, and Radagast, then saying he can't remember the names of the other two, merely saying, "The two blues." Their names, Alatar and Pallando, appear in the book Unfinished Tales, a collection of J.R.R. Tolkien ideas and half-manuscripts edited into book form by his son Christopher Tolkien. The filmmakers didn't have rights to use material from that book, so the two blue wizards remain unnamed in the film.
In the Lord of the Rings films, the scale illusion was accomplished by playing hobbit or dwarf actors further away from the camera than Ian McKellen, but still live on the same set. This time, however, the illusion had to be accomplished by having the other actors on a completely different set, while McKellen performed his, all alone, on a green-screen set, with only an earpiece connecting him to the performance being provided by the rest of the cast. McKellen ended up feeling lonely and frustrated, to cheer him up, the cast and crew sneaked into the tent he stayed in during breaks, and decorated it with mementos from the Lord of the Rings films, and stocked it with records and a player so he could listen to music.
Frodo (Elijah Wood), Saruman (Christopher Lee), Galadriel (Cate Blanchett), and Legolas (Orlando Bloom) are all returning characters from the Lord of the Rings films though none of them actually appear in the book The Hobbit. This is the same for Radagast (Sylvester McCoy), who is only mentioned in The Hobbit but does not actually appear until The Lord of the Rings. Conversely however, Radagast was omitted from The Lord of the Rings films.
Azog was a last minute digital addition to the film. He was originally an actor in prosthetics, but Peter Jackson found the effect lacking presence, and had Weta create a digital character, mo-capped by actor Manu Bennett, and insert the character over the previously-filmed live Azog footage. The original Azog appears in the film as Yazneg, the ill-fated Orc lieutenant.
Dwalin uses two large battle axes in combat. Graham McTavish suggested to Peter Jackson that the axes each be named after Emily Brontë's dogs, "Grasper" and "Keeper". Jackson went for the idea & Dwalin's axes were engraved with both names in Dwarvish runes. He also named his knuckledusters "Insult" and "Injury."
Christopher Lee (Saruman) once commented that he would have loved to voice the Dragon Smaug in a film adaptation of 'The Hobbit'. Instead, he voiced the dragon-like Jabberwocky in Alice in Wonderland (2010).
The Hobbit is the first feature film to be shot and projected at 48 frames per second, twice as fast as the industry standard of 24 frames. The intention of this is to provide the film smoother, more realistic motion with reduced strobing. This is particularly beneficial when viewing the film in 3D, as the higher frame rate helps to correctly synchronize the images for each eye. There were controversies about the frame rate with many viewers complaining about the poor quality in certain theatres due to improper equipment and inexperienced projectionists not knowing how to make proper adjustments.
In the second trailer, Gandalf can be heard saying, "Home is behind you, the world ahead..." this is a quote from the original Lord of the Rings trilogy, written by J.R.R. Tolkien for the books; it is part of the song which Pippin sings to Lord Denethor in The Lord of the Rings: The Return of the King.
This is the first Middle-Earth film directed by Peter Jackson that does not have any speaking characters that are ordinary humans, known in the work of J.R.R. Tolkien as the "race of Men." Some men appear in the opening flashback but do not speak. Hobbits are technically descended from the race of Men, and Wizards are strictly not man even though they appear so.
Peter Jackson is the third director after James Cameron and Christopher Nolan to make 2 films that have grossed more than $1 billion worldwide (As of April 2013, The Hobbit: An Unexpected Journey has grossed $1,016,944,389 worldwide.).
Saruman, Gandalf and Radagast are also known as "the white", "the gray" and "the brown", respectively. These nicknames match straightly with their clothes and hair. In addition, Saruman is the only one not having hat or cloak over his head, a symbol of his status as leader of the wizards.
The method of creating hobbit feet was changed for this film. For the Lord of the Rings trilogy, the prosthetic feet only fitted over the actors' feet, requiring them to be re-applied after periods of walking in them. For this film, the prosthetic went all the way up to the actors' (Martin Freeman, Ian Holm and Elijah Wood) knees.
Thranduil, the father of Legolas, first appeared in the Hobbit book simply as "The Elven King" with no mention of his real name. Is it only in The Lord of the Rings, when Legolas first appears in the books, that he is identified as the Son of Thranduil of Mirkwood. When Legolas enters Lothlorien in The Lord of the Rings: The Fellowship of the Ring (2001), Haldir greets him in Elvish as "Legolas Thranduillion."
This is the second film in which Saruman considers a fellow wizard to be mentally inept due to plant consumption. In The Lord of the Rings: The Fellowship of the Ring (2001) he suggests that pipeweed has slowed Gandalf's mind. Here, he suggests mushrooms have rendered Radagast a fool.
This movie went through several stages of pre-production hell, including separate legal disputes between New Line Cinema, Peter Jackson, and Tolkien family members which complicated production. When MGM finally moved the project forward in 2008 more complications ensued when MGM entered bankruptcy and froze production, causing director Guillermo del Toro to step down after three years of pre-production. Later, it was almost cast out of New Zealand when several unions and guilds blacklisted the project and shooting was delayed again while Peter Jackson recovered from surgery from a perforated ulcer.
In 2009 an Internet rumor linked David Tennant to the role of Bilbo Baggins, after he and Peter Jackson both appeared at Comic Con. Both Tennant and Jackson denied this rumor, stating he was never under consideration for the role. However, in 2010 Tennant was considered for the role of Thranduil, but had to turn it down when his then-girlfriend (later wife) Georgia Moffett unexpectedly became pregnant which prevented him from taking part in film's lengthy New Zealand shooting schedule.
This is not the first of Peter Jackson's pet projects where he has asked Guillermo del Toro to direct; del Toro was also offered to helm the now troubled Halo movie, but he turned it down to direct his own pet project Hellboy II: The Golden Army (2008). Del Toro did accept the chance to direct this film, but after years stuck in pre-production limbo, he left to pursue other projects.
Jed Brophy, who plays Nori, is the only dwarf who also appears in The Lord of the Rings Trilogy, although this is the first time we see his face. If you listen to the Writers and Director commentary on the extended version of The Lord of the Rings, Peter Jackson identifies him several times as playing various orcs and background people, including Sharku the Warg Rider, the orc that Aragorn fights in The Lord of the Rings: The Two Towers (2002)' cliff scene.
The opening scenes, in which Ian Holm plays the older Bilbo, do not appear in the book, which is told in present-time, not as a flashback. Shortly after the release of The Lord of the Rings: The Fellowship of the Ring (2001), Holm recorded similar scenes; this time as Frodo; for inclusion in a new boxed set version of the BBC Radio version of The Lord of the Rings.
Radagast (Sylvester McCoy, né Percy Kent-Smith) allows animals to hide in various parts of his robes. While his friendship with animals is consistent with the book, this may also be a nod to Kent-Smith's early stage act, Sylveste [sic] McCoy (from which he took his professional name), in which he stuffed ferrets down his trousers.
Robert Kazinsky was cast as Fili and had filmed a few scenes, but left the project and returned to England about a month after filming started due to personal reasons. He was replaced by Dean O'Gorman.
The trivia items below may give away important plot points.
When Gandalf, Bilbo, and the dwarves arrive at Rivendell the wizard mentions it's also known as "Imladris". This name is a word in Elvish (a fictional language created by J.R.R. Tolkien) and both names mean "deep valley of the cleft". Rivendell was established and ruled by Elrond in the Second Age of Middle-Earth, about four or five thousand years previous to the Lord of the Rings events.
The ghost who attacks Radagast in Dol Guldur is Witch-King of Angmar, the same who stabs Frodo on Weathertop in The Lord of the Rings: The Fellowship of the Ring (2001). The Necromancer spotted by Radagast is the first sign of Sauron's re-manifestation in Middle-Earth.
When Bilbo, Gandalf and the dwarfs arrive to the edge of the cliff just before of the fight against Azog and his orcs, a familiar landscape can be seen in the distance. This landscape is the same seen by Merry, Pippin and Treebeard in The Lord of the Rings: The Two Towers (2002) when these three see the Saruman's Uruk-hai armies moving to Helm's Deep.
When Elrond examines and gives the sword Orcrist to Thorin, in the middle finger of his left hand can be seen a ring. This ring is Vilya, one of the three rings given to the Elves at the beginning of the Second Age of the Middle-Earth, and seen in the prologue of The Lord of the Rings: The Fellowship of the Ring (2001). Vilya is a word in Quenya, a fictional language created by J.R.R. Tolkien, and means "air".
The explanation of Elrond about Orcrist and Glamdring, the swords found in the troll cave by Gandalf and Thorin, is suddenly cut by a dialogue between Bilbo and Balin. Orcrist and Glamdring were forged in the First Age of the Middle Earth for Ecthelion and king Turgon respectively, to fight against the Balrogs sent by Morgoth (the first Dark Lord before Sauron) to rule the Middle Earth.
The orc that Gollum kills was played by an actor wear an animatronic head and then covered in full-body prosthetic make-up. Andy Serkis was so aggressive in hitting the forehead with the rock that the electronics inside were broken and had to be repaired for more takes the next day.
The answers to riddles proposed by Gollum and Bilbo, including the first riddle said by Gollum after the game, are these: 1st - a mountain, 2nd - teeth, 3rd - wind, 4th - eggs, 5th - time, and 6th - The One Ring.
The riddle competition at the end between Bilbo and Gollum is inspired by the Norse legend of the riddle competition between the wise giantess Vafþrúðnir and Odin, the mayor god in Germanic Mythology (who is also an inspiration for Gandalf). Bilbo wins the competition by asking what lies in his pocket, a question only he could know the answer to. This is exactly the same way Odin wins over Vafþrúðnir: by asking "what did Odin whisper in his dying son Baldr's ear?" A question only he would know the answer to.