Marvel's superhero blockbusters have dominated the box office for years, going back to the days of Blade, the original X-Men and Sam Raimi's Spider-Man, but the foundation on which they were built was actually laid almost a decade earlier. While nothing would have been possible without the comics in the first place, the revolutionary era of '90s animation had a big hand in charting the genre's course to the big screen.

Animated versions of DC and Marvel's pantheon of characters appeared during the Silver Age of comic books, mostly as Saturday-morning cartoons aimed at children. Due to the content being made for kids and featuring heavy censorship, both from the Comics Code Authority and the FCC, the stories came off as relatively silly and naive. The Fantastic Four's ridiculous encounter with the Super-Skrull in Season 1, Episode 4 and The New Fantastic Four's defeat of Magneto with a wooden gun in Episode 2 illustrate the era's tone to a tee.

In addition, shows almost never adapted comic book storylines, an almost standard practice today that is often taken for granted. For instance, Spider-Man and His Amazing Friends was based on a friendship between Spider-Man, Iceman and Firestar, which had little basis in any existing comics. Meanwhile, the Super Friends' Darkseid was at times more focused on impressing Wonder Woman than he was with dominating the universe.

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Super Friends

The style began to change, at least for Marvel, when Margaret Loesch became head of both Marvel Productions and Fox Kids. Despite the immense marketing potential of superheroes, Marvel was facing bankruptcy at the time, having to sell the rights to some of their most valuable properties just to stay afloat.

Loesch was passionate about the value of Marvel's portfolio and championed the creation of the now well-known X-Men: The Animated Series. However, Loesch and her creative team wanted to do something different this time around. The new vision was described most succinctly by showrunner Eric Lewald when remembering the over-the-top voices some actors tried during casting sessions.

"[The actors] thought, 'They want to do something goofy and childish,'" Lewald said. "They didn't get it."

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The idea was to make the narrative more serious and thematically complex, crafting multi-episode storylines to honor existing comic book arcs, such as Days of Future Past and Dark Phoenix. The crew often faced increased production costs associated with the interconnected episodes that troubled the studio, and many claimed to have risked termination because they opposed the demand to "dumb it down or make it younger." Their resolve was rewarded when the first season skyrocketed to the upper echelon of television ratings, drawing viewership numbers closer to that of a primetime show than a Saturday-morning serial.

X-Men Animated Series Cyclops and Jean

Several years later, a new Spider-Man series would also premiere to rave reviews, continuing the practice of drawing from the comics source material and constructing overarching storylines, such as Secret Wars. On top of introducing the web-slinger to a whole new generation of fans, the show also relied on now common cross-franchise appearances, featuring everyone from Daredevil and Dr. Strange to Red Skull and Doctor Doom, as well as one of Stan Lee's first on-screen cameos in a Marvel property.

Though the X-Men show also had characters from other properties, Spider-Man: The Animated Series was always more proactive in employing the tactic, evidenced by the animated X-Men appearing on an episode of Spider-Man instead of the other way around. It even pulled off what can be argued to be the first on-screen Spider-Verse crossover event when the final season's last two episodes had Peter team up with alternate versions of himself to save the multiverse.

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Spider-Man's showrunner John Semper and writer Stan Berkowitz are also more bullish on the animated series' connections to the later live-action films. In a 25th anniversary panel, Berkowitz suggested, with Semper's support, that producer Avi Arad, who owned the character at the time, used the show to better understand the process of adapting Spider-Man for a feature film. At the same panel, Semper also claimed the idea of portraying Blade, another one of the show's many cameos, as a half-vampire hybrid was initially his. This depiction of Blade seemed to influence the feature film, whether intentional or not.

Spider-Man Animated Series Spidey With Girl

DC may have also experienced a revolution in animation, but the links between their feature films and their animated series are much more complicated. For one, both Superman and Batman had already found cinematic success in previous decades, meaning future filmmakers relied more on prior films than animation.

The DC shows were also much better funded thanks to backing from Warner Brothers, suggesting studio executives were already comfortable with a mature style and did not need to be convinced. There was definitely some influence that carried over, especially considering Harley Quinn now has her own movie after debuting in Batman: The Animated Series, but '90s animation didn't seem to shift the paradigm for DC quite as much as it did for Marvel.

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Therefore, it's no surprise that the two live-action films that kickstarted the "modern" era of superhero films were X-Men and Spider-Man, the innovators of the preceding animation era. Since then, Marvel films have made a point of telling compelling stories with flawed individuals, incorporating comic book references and integrating the properties into one shared universe. These ideas may have seemed absolutely revolutionary when all the major heroes united in The Avengers, but there was already ample animated evidence that such storytelling would appeal to mainstream audiences.

The days of random stories that just happened to feature Marvel heroes are long gone, replaced by a much finer and more satisfying approach. The origin of this shift can be found in the willingness of comic writers to explore darker themes, but without a crew showing it was possible to translate those stories to the screen, there's a high chance the genre may have taken a much longer time to be considered serious enough to warrant major funding. Fans will undoubtedly carry these shows in their hearts as sources of nostalgia, but they also represent a major stride for how superheroes are perceived on-screen.

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