Iron Man's signature armored suit was cool back in 2008 and has withstood the test of time, but one behind-the-scenes detail makes Tony Stark's first MCU suit even better. 2008 was a landmark year for superhero movies with the theatrical releases of both The Dark Knight and Iron Man. Of course, the success of Iron Man would eventually lead to the greater MCU which shows no signs of slowing down 15 years later.

It's easy to take the MCU granted now given its cultural heft, but the possibility of a Marvel Cinematic Universe existing at all depended on Iron Man doing well both critically and commercially. Luckily, the superhero flick directed by Jon Favreau succeeded resoundingly well on both fronts and even managed to nab two Academy Award nominations in technical categories. More importantly, Robert Downey Jr. ended up being the perfect match for Tony Stark, and Iron Man’s suit ended up being a perfect match for the former Chaplin actor.

Related: All 19 Iron Man Suit Versions Tony Stark Wore In The MCU

Robert Downey Jr. is now synonymous with Tony Stark and Iron Man, but Marvel initially didn't want to cast Robert Downey Jr. because of the actor's scandalous past. A different actor taking on the role of the MCU's Iron Man is an incredible thought exercise in its own right, but another amazing detail is how Iron Man's red-and-gold suit was designed and created for the superhero's live-action feature film debut. According to a documentary extra that was included in Iron Man’s Blu-ray release, it turns out a not insignificant amount of the work had already been completed before anyone had an idea of who might be portraying Tony Stark/Iron Man.

Why An Uncast Iron Man Made A Harder Suit Design

Tony Stark (Robert Downey Jr) kills the power in 2008's Iron Man.

Doing the bulk of the design work for the most important costume in an incredibly important movie like Iron Man seems more befuddling than why Iron Man's MCU suits got weaker instead of stronger. However, according to Physical Suit Effects Supervisor Shane Patrick Mahan, that was exactly how the process went down with the design, concept, and practical effects teams. Not only were there already design ideas in place when the practical effects teams were brought in, but Mahan notes that "the big challenge was the fact that they hadn't cast anyone to be Iron Man."

Given how well the suit turned out, that seems like a minor miracle. Costumes – even sports jerseys – tend to sparkle or sizzle depending on who is wearing any given costume or uniform. That Iron Man nailed the suit to the extent that Robert Downey Jr. stepped in and literally and figuratively fit perfectly is quite an accomplishment. It’s further testament to the amazing design of really all of Tony Stark's live-action armored suits that fancasts from John Stamos to Tom Cruise as the MCU's Iron Man tend to look particularly convincing.

Iron Man’s Oscar nominations didn’t include Best Costume Design. Mahan and the other talented people who worked behind the scenes to bring Iron Man’s suits to life did receive a nomination for Best Visual Effects. However, the true impact of their work and Robert Downey Jr.’s contributions to Iron Man, the very first MCU film, and to the character Iron Man’s first MCU suit live on vicariously through his ongoing legacy.

Next: Ironheart's First MCU Costume Has 1 Major Iron Man Suit Difference

Key Release Dates