Just before the race to the Eiffel Tower, Breaker takes Duke's last piece of bubble gum. This is an homage to the Breaker comic book character, who was often seen or reprimanded for chewing gum during missions.
In real life, "G.I. Joe" was a generic term for general infantrymen in the United States Army during World War II. In an early script for this film, G.I.J.O.E. was going to be used as an acronym for "Global Integrated Joint Operating Entity." It was later decided not to go this route after a huge outcry from Joe fans and patriots prior to the movie's editing.
Channing Tatum originally didn't want to act in this film because he felt it glorified war. He changed his mind when he read the script. His friend and Stop-Loss (2008)-co-star Joseph Gordon-Levitt also encouraged him to sign on.
Martial artist/stuntman Ray Park had little knowledge of the G.I. Joe saga, but as a child he had played with a Snake-Eyes action figure. He was thus delighted to play a childhood hero of his. To prepare for the role, he practiced wushu training and studied Snake-Eyes's appearances in the G.I. Joe (1985) comic/television series. Afterwards he approached writer Kevin VanHook and artist S. L. Gallant with the idea of a G.I. Joe comic further exploring his incarnation of the character.
According to Brian Goldner, the writers took their inspiration mostly from Larry Hama's G.I. Joe comics, and not the G.I. Joe (1985) animated series. Lorenzo di Bonaventura admits he feels the Cobra Organization, as depicted in the cartoon, was "probably the stupidest evil organization out there!"
The Paris action scenes were filmed in 14 days in Dejvice, Czech Republic, in Prague. Filmmakers built shops with flowers, changed school names, and parked many old French-manufactured cars in the area. The Barron's laboratory was filmed in Vysocany in the headquarters of the big company Sazka.
Stephen Sommers took great care over the technology depicted in the film, going through various books/magazines about weapons technology. He feels that almost 100% of the technology can be developed within 10-20 years.
Byung-hun Lee, who plays Storm Shadow, had no knowledge of the G.I. Joe saga, but was advised by the filmmakers not to learn about his character, letting his portrayal stand by itself. He describes Storm Shadow as defined and driven by two conflicting facets: "huge pride and a sense of honour."
James McCullen alias Destro is the head of M.A.R.S. Industries. In the G.I. Joe universe, "M.A.R.S." stands for "Military Armaments Research Syndicate"; it is also a reference to Mars, the Roman god of war.
In an interview in Top Gear (July 19, 2009), Sienna Miller, said 112 cars were destroyed during filming. She also said it was a record number of cars destroyed in a movie [at the time of the interview].
112 cars were crashed during filming. This beat the previous world record of 104 cars crashed during the making of Blues Brothers 2000 (1998). The figure of 112 does not include cars that were blown up.
According to Stephen Sommers, total invisibility is impossible, but the camouflage cameras in the film (they project the view from a soldier's back onto their front) can allow for virtual invisibility.
The Delta-6 accelerator suits delighted Stuart Beattie and made him write up "a car chase where one guy's not even in a car!" However, they were bulky and heavy for the actors to wear and for any planned sequels their use will be reduced.
Ray Park was nervous about wearing the ninja suit and asked to practice with it at home so that he could be comfortable with it. He found the suit (composed solely of rubber with a metal visor) like wearing a rubber band, and had to put effort into moving in it.
The Cobra Night Raven in the film differs greatly from its comic book and G.I. Joe (1985) animated counterparts. In the comics and the series, it's based on the SR-71 Blackbird. In the movie, it's very much like the MiG-31 from the movie Firefox (1983).
Duke and Ripcord train with FN model FS2000 Tactical series assault rifle in NATO 5.56x45mm (.223 Rem). During the elevator sequence, the Baroness uses an H&K MP7 in 4.6x30mm. Both are very real, very successful, futuristic-looking weapons. Snake Eyes' pistol is modeled on the FN Five Seven semi-auto pistol, which is also a real weapon. Instead of energy-based projectiles, the real gun shoots small-caliber 5.7x28mm rounds.
As Duke and Ripcord avoid the missiles launched from the Steel Crusher A.P.V., the camera moves in front of them and briefly slows down, framing the two men with an explosion behind them: just as in the card art for the 1980s figures.
Hama, the creator of G.I. Joe (1985), was hired as a creative consultant on the film. He also got a cameo, as a NATO general during the nanomite presentation. The role was cut during editing, and he can only be seen in wide shots of the NATO assembly.
A post-credits scene was planned, in which famously mute ninja Snake-Eyes tells a joke to the G.I. Joe team. Larry Hama advised against it because it would detract from the seriousness of the film, as well as go against the core of Snake-Eyes' character, who has always been portrayed as a complete mute.
David Murray was cast as Destro, but dropped it when he had problems with his visa. He was replaced by Christopher Eccleston; however, the character was named James McCullen XXIV, thus enabling Murray to film a flashback scene as the first Destro, James McCullen I.
Skip Woods wrote an early draft of the film, which featured Alex Mann (aka Britain's Action Man) and the antagonist as the Naja/Ryan, a corrupt CIA agent. Scarlett is married to Action Man but still has feelings for Duke, and is killed by the Baroness. Snake-Eyes speaks, but his vocal cords are slashed during the story, rendering him mute.
For the voice of the Cobra Commander, Joseph Gordon-Levitt was partly inspired by Chris Latta's voice from G.I. Joe (1985), but he also used a bit of his own imagination as he felt that copying Latta's voice fully would be unoriginal and ridiculous.
While Karolina Kurkova described being part of the film as an amazing experience, she was upset that she didn't get to take part in any action sequences, due to her character, Cover Girl, being killed off by Zartan.
A clue to Zartan's mission can be found early in the film. When first seen, Zartan is sitting at a table aboard McCullen's submarine reading a book. The book is on the Bill of Rights, and he makes remarks about USA government inefficiency, so he is preparing himself for his future role.