In the bar, the TV is showing a debate on the mutant situation. One of the panelists is "Dr. Hank McCoy," which is the real name of the blue-furred behemoth X-Man, Beast. The other, not seen but called "Dr. Shaw," is presumably Dr. Sebastian Shaw, the leader of the Hellfire Club in the comics.
On Yuriko's computer, the following files are listed: Guthrie (2) (Paige (Husk), and Samuel (Cannonball)); Harada, Keniucho (Silver Samurai); Kane, Garrison (Weapon X); LeBeau, Remy (Gambit); Lensherr, Eric (sic) (Magneto); Maddicks, Artie; Madrox, Jamie (Multiple Man); Xi'an Coy Mahn(Karma);Maximoff (2) (Wanda (Scarlet Witch), and Pietro (Quicksilver)); McTaggart, Kevin (Proteus); Moonstar, Danielle (Moonstar); Munroe, Ororo (Storm); McCoy, Hank (Beast); Callasantos, Maria (Feral); Cassidy (2) (Sean (Banshee), and Tom (Black Tom); Cheney, Lila; Creed, Victor (Sabretooth); DaCosta, Roberto (Sunspot); Dane, Lorna (Polaris); Drake, Bobby (Iceman); Dukes, Fred (Blob); Espinosa, Angelo (Skin), and; Gibney, kyle (Wild Child). On another screen there were a series of folders on the computer's desktop. These folders listed some well-known individuals or places from the X-Men universe, including: Omega Red (Russian mutant super soldier), Muir Island (Scottish mutant research facility), Project Wideawake (Codename for Sentinel project), Franklin Richards (son of Fantastic Four's Reed Richards and Sue Storm; born a mutant), and Cerebro (mutant tracking device created by Professor Xavier and Magneto). Closer inspection reveals that Stryker is keeping files on Pyro, Sabra, Dr Ceclia Reyes, Synch, Penance, Nightcrawler, his own Mystique and Lady Deathstrike, Copycat, Deadpool, Cyclops, Dazzler, the von Struckers, Jamie Braddock, David North, Sunfire, Boom Boom, Mimic, Dr Nathaniel Essex, Toad, Wolfsbane, Strong Guy, Kitty Pryde, Sauron, Forge... Curiously, there seem to be no files for Jean Grey or Wolverine, among others. There are also files on Alpha, Beta and Gamma Flights, Weapon X, Project Wide Awake (sic), Dept H, the Brotherhood, Graymalkin, Zero Tolerance, Massachussets Academy, Blackbird, the Danger Room, Legacy, Morlocks, Xavier's School, Omega Red, Cerebro, the Salem Centre, Franklin Richards, Kevin McTaggart, and Trask.
Professor Xavier's wheelchair from the first movie was bought by a lawyer (who also works for the same law firm as Patrick Stewart's attorney). When production began, the studio realized they had no chair anymore, so the lawyer rented it back to the studio - as Stewart said in an interview - "for a significant sum".
When Wolverine is in the kitchen in Bobby Drake's parents' house, and he is surprised by the cat, he lets it lick his claws - seemingly a very cute moment. But if you listen closely when he hears someone come in and retracts his claws, you hear the sound effect of Wolverine's claws extending (if you listen closely, you can tell the difference, as the retracting sound is the same as the extending sound, but played in reverse), and then the cat crying out. This was an unintentional moment of comedy which was going to but cut but the last minute decision was made to leave it in.
The set for Stryker's underground lair was built in an old Sears warehouse and was the largest set in North America. It involved over 60 miles of cable and was so large that cast and crew members used bicycles to get them to and from the bathroom as quickly as possible. Even then, the production only used about half the space in the warehouse.
Another huge set was the turbine hall of an old dam which housed a museum. Unfortunately the museum was painted in bright, lurid colors, so the production design team had to dress it up to make it look old and dank (something which horrified the museum administration until they realized that it was just temporary).
Health and safety restrictions meant that helicopter blades were not allowed to be moving when the actors - in this case, Rebecca Romijn and Ian McKellen - were sitting inside the helicopter. The moving blades had to be added in digitally afterwards.
Several sets for the film were not used. Some of these sets included the Danger Room and several areas in Stryker's underground bunker. One room in Stryker's underground base was going to be the setting of a Nightcrawler vs. Toad fight.
An early draft of the script had Magneto saving Professor X from Dark Cerebro and escaping with the other X-Men, similar to what happened in the comic graphic novel that the film is based on. According to director Bryan Singer this was changed late in production not only to remain true to Magneto's ruthless character, but also to give the other characters - namely Nightcrawler and Storm - something more to do in the film's climax.
On The Tonight Show with Jay Leno, Hugh Jackman related a story about something that happened during the filming of the Weapon X flashback scene: while he was filming the corridor run (in which he is nude and backlit), he turned the corner and saw the female cast members, including James Marsden's mother, waiting for him, hooting and waving dollar bills.
There was an extended scene that doesn't appear in the final film, nor as a deleted scene on the DVD that features Cyclops's fight with Yuriko (Lady Deathstrike), where he picks up and fights with the two prison guards' plastic nightsticks.
The set from the bathroom scene where Mystique incapacitates the prison guard and injects him with a foreign substance is actually an unused set from X-Men. The scene in question (written and storyboarded, but not shot) involved Cyclops manifesting his powers as a teenager, destroying a high school bathroom.
Alan Cumming was Bryan Singer's first choice for the role of Nightcrawler. However, during initial casting, he was unavailable. The project labored in development long enough that by the time the film was ready to shoot, Cumming was able to come onboard. Ethan Embry was rumoured to have won the role before Cumming was available.
Two of the voice actors from X-Men: Evolution appear in the movie. David Kaye who voices Professor Xavier appears as a TV announcer. Chiara Zanni who voices Jubilee/Jubilation Lee appears as a white house tour guide.
The final scene in Xavier's mansion with Cyclops, Wolverine and Professor X was shot at Shepperton Studios in London, simply because Hugh Jackman was shooting Van Helsing at the time and the producers released him for only one day to do the final shooting of X-Men. The reason Wolverine's hair looks higher than usual in this scene is because Jackman had long hair for Van Helsing and had to wear the Wolverine wig over a lot of hair.
When Wolverine visits the adamantium processing chamber of Stryker's Alkali Base, there is a wall covered with x-rays detailing the adamantium bonding process. On the far right is an x-ray of what appears to be a left wing. The DVD acknowledges this as a hint to a winged character named Angel. In the comic books, Angel's wings are replaced with metal ones and he becomes Archangel.
The White House oval office is an exact recreation, but the corridors in the opening chase between Nightcrawler and the Secret Service, were wider than the actual walls to allow more room for fighting.
Magneto's line "When will these people learn how to fly?" is a reference to the fact that some of the characters (Jean Grey and also Rogue, who gets the ability from permanently absorbing Ms. Marvel's powers in the comics) have the ability to fly in the comics but haven't yet in the films. The only characters with the power of flight in the comics that have shown this ability in the movies are Magneto and Storm (although Storm was manipulating wind currents to levitate herself, and Magneto was only able to levitate by standing on metal - presumably he wears shoes with metal sole-plates to do this in other occasions).
When Mystique reviews the information on the security guards at the facility housing Magneto, the following names are displayed, referencing crew members of the film: DeSanto, T. (Tom DeSanto, executive producer); Dougherty, M. (Michael Dougherty, screenwriter); Donner, L. (Lauren Shuler Donner, producer); Young, R.D. (possibly Rob Young, production sound mixer); Harris, D. (Dan Harris, screenwriter) C. L. G. - Classified; R. G. M. - Classified, and; Singer, B. (Bryan Singer, director). Bryan is the only one who gets his own photo - the others, including Ms. Donner, are given stock male guard photos.
The music played in the opening scene when Nightcrawler attacks the White House is "Dies Irae" from Wolfgang Amadeus Mozart's Requeim. (Alan Cumming, who plays Nightcrawler, shares the same birthday as Mozart.)
Initially, during the "Dark Cerebro" scene where it is attempting to kill all mutants, Bryan Singer had planned to show not only Cerebro's effects on the mutants in the Alkali Base, but mutants all over the world. During this scene, Hank McCoy, aka Beast (Steve Bacic), as seen earlier on the television during the bar scene, was to be shown in agony, transforming into his furry form, and fan-favorite Gambit was to be shown at a card game having his energy powers flare up. This scene was actually shot, using one of Hugh Jackman's stunt men, James Bamford as a stand-in for the role, shot from behind to remain ambiguous. For whatever reason, Singer decided to cut this sequence altogether and it remains unseen.
The Danger Room, the area where the X-Men train and hone their powers, was going to be included in this film. Bryan Singer had wanted it to appear in the first film, but due to budget cuts, the idea had to be scrapped. It was then worked into the story for this film, to take place when Wolverine is left to watch after the students in the mansion. He decides to do a workout in the Danger Room, which was going to segue into the scene of him lying down and having a vision of Stryker and his Weapon X procedure. The Danger Room was going to be a cylindrical-shaped room, with different sections of the floor raising and lowering at dangerous speeds, as well as holographic projectiles, etc. The earliest teaser trailer for the film gave a sneak peak at how the Danger Room was going to look, but shortly after this teaser was released, Fox cut Singer's budget down from $125 million to $110 million, forcing Singer to once again cut the Danger Room from the film. There is still a small reference to the Danger Room remaining in the film: when Stryker first enters the X-Mansion subbasement, directly opposite from the elevator is a door with a small label on it, which, according to Singer's DVD commentary track, identifies the door as the entrance to the Danger Room.
Kurt Wagner's x-rays are all given the same id: C13957. They are all dated May 22/84, and taken by Dr D.Mintz (69) at the offices of "Drs Green, Chetwynd, Gough, Switzer, Siu, Fulton, Bentley, Murray. Radiologists. Vancouver, BC"
The sunglasses worn by Cyclops are Oakley Pennys, although they look very similar to the glasses he wore in the original X-men they are in fact a different model (with Oakley Juliets appearing in the first film), both were modified with blinders around the lens. Oakley were also responsible for manufacturing the visor which Cyclops wears and in some shots Oakleys logo (a horizontally stretched "O") can be seen on the parts of the visor that cover Cyclops' ears.
When Jean is hearing people's thoughts in the Science Museum, one of them is "To the shelter!" This line was said by one of the Secret Service during Nightcrawler's attack on the Oval Office in the previous scene, thus adding/alluding to Jean's growing psychic abilities. Other lines Jean hears are "No!" shouted by Wolverine when he later is separated from General Stryker by Iceman's wall of ice and "They're gonna kill him." which is what Rogue later says to Iceman and Pyro in the tunnel pleading for them to go back and help Wolverine.
The character Rogue, whose surname has never been revealed since her introduction in the comics in 1981, was given a surname for this film - Marie D'Ancanto. Comic writer Chris Claremont, Rogue's creator, has used this name since the movie's release in the "X-Treme X-Men" comic, but for a different character.
According to Bryan Singer's commentary, he removed a couple of seconds of footage after Wolverine stabs a soldier in the kitchen during the raid for ratings purposes. But the extended sequence can be seen as deleted footage in the Supplemental Features disc. The extended sequence was also featured in the theatrical version in other countries (ex: Brazil).
Xavier's School for the Gifted is located on "Graymalkin Lane, Salem Center". "Graymalkin" was the name of the witches' cat in Macbeth (Act I, Scene I: "I come, Graymalkin!"), and Salem Village (present-day Danvers, MA) was the location of the infamous witch trials in the 1690s.
The German phrases that Nightcrawler shouts to Storm and Jean in the Boston church are "Gehen Sie raus! Ich bin ein Büttel des Teufels! Ich bin die Ausgeburt des Bösen!" They translate to "Get out! I am a minion of the devil! I am the spawn of evil!"
Alan Cumming, who played Nightcrawler, would not appear in the third X-Men movie because the crew believed it wasn't worth going through the long preparation. This also include the fact that Cumming did not enjoy to put on the heavy make-up because his appearance was minimal. So, it was written in the video-game storyline that Nightcrawler did become a X-Men member, but decides to leave because he no longer wanted to live the violent lifestyle that X-Men have to endure.
Director Bryan Singer credits the X-Men graphic novel "God Loves, Man Kills" (released in 1982) as an influence for the script. As in the film, the novel concerns William Stryker (a religious leader instead of a military one) building a replica of Cerebro and kidnapping Professor Xavier so he can use it to kill all mutants. The X-Men are forced to ally themselves with Magneto to stop him.
Guy Hendrix Dyas and sculptor James Jones collaborated on designing a Sentinel (in the comics, the Sentinels were a set of mutant-fighting robots constructed by anti-mutant government officials). Their final design was a complex hollow robot that could compress itself into a discus. Animating the Sentinel would have cost about seven million, so the Sentinel was never used in the film.
In the film, William Stryker is an army colonel who perceives mutants as a threat. In the comics, he is a Christian fundamentalist televangelist who uses religion and his sacred belief of all mutants being satanic to rally anti-Mutant bigotry. He even set up his own hate group in the comics called "The Purifiers" to eliminate mutants in a holy crusade.
Chuck Austen, who has written extensively for the character of Nightcrawler, revealed on the DVD that he was asked if there was anything he knew about the character that nobody else did. He suggested that, just like the character has two fingers on each hand and two toes on each foot, he also had two sets of genitals.
Originally the idea was that Jean Grey was temporarily rendered blind after her violent reunion with Cyclops. This was initially filmed as such, but ditched during production, but in the scene where Wolverine shuts a dam door, saving the X-Men from a wall of water, Jean Grey is the only character not looking at him.
According to Bryan Singer, he conceived the idea of Jean Grey's death mid-way through production. During the filming of the museum scene, he privately met with Famke Janssen to discuss the concept of Jean dying at the end of this film, with the allusion to her return as Phoenix (as in the comic book mythology) in the next sequel. Janssen enthusiastically agreed.