* CaliforniaDoubling: Spectacularly averted for the most part, with only a few minor exceptions:
** Scenes from Zürich and the French countryside in ''Identity'' were filmed in the Czech Republic (in and around Prague), The skyline of and scene taking place in Amsterdam in Supremacy are probably filmed there as well and the very brief re-appearance of Moscow in ''Ultimatum'' was filmed around old [[UsefulNotes/EastGermany GDR]] era buildings in UsefulNotes/{{Berlin}}.
** In ''Ultimatum'' they filmed a scene set at the Waterloo train station on location, but there was no way they could get the location shut down for filming, so they just worked around the crowd. It generally worked alright as they put up signs to please ignore the film crew.
** Calgary, Alberta served as Alaska, but that doesn't mean Creator/JeremyRenner didn't actually get into glacier water with little protection.
* DoingItForTheArt: In ''The Bourne Legacy'', Creator/JeremyRenner actually entered glacier water with little protection.
* FakeAmerican: Creator/BrianCox (Ward Abbot) is Scottish
* StarMakingRole: Creator/MattDamon has mentioned that despite getting wildly critical acclaim for previous movies, it wasn't until he proved to have Box Office clout that film offers really started to show up.
* UnderageCasting:
** Creator/JuliaStiles played Nicky Parsons, one of Jason Bourne's field handlers on an extremely sensitive mission and apparently has beyond Top Secret clearance given what she is involved in (monitoring all of the Treadstone field agents). In other words, significantly more dangerous to the Agency than Bourne is if she screws up, or if something was missed in her vetting and she is less than 100% loyal. When ''The Bourne Identity'' was released, Stiles was a very young looking ''21''. There's an attempted HandWave in ''The Bourne Supremacy'' when Nicky explains [[OlderThanSheLooks her cover was an exchange student studying in Paris]].
** In ''Jason Bourne'', unless Alicia Vikander's character is older than she is, the audience is being forced to believe that a 27-year-old could have a high-ranking position in the CIA. Her demands at the end of the film to be put in an even higher ranked position highlight this.
* WhatCouldHaveBeen:
** Creator/BradPitt turned down the role of Jason Bourne.
** Creator/CliveOwen was the sniper assassin towards the end of the first movie. In the lead up to ''Film/CasinoRoyale2006'' he was one of the people in the running for the role of Film/JamesBond, which would have made this movie just a little funnier in hindsight. Still, you can always imagine it was either [[Film/ShootEmUp Smith]] or [[Film/TheInternational Salinger]].
** The original draft of the first film [[http://gulfnews.com/life-style/celebrity/hollywood/julia-stiles-gave-up-her-adult-life-to-jason-bourne-1.1871485 would have seen Nicky die]] by having her thrown against a wall and breaking her neck. The scene was recut to have her live so that she could appear in a sequel, which she did.

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