Twenty years ago, superheroes weren't just unpopular - they were dying.

The most recent cinematic adaptations were Joel Schumacher's two Batman films, most notably Batman and Robin, the one with the bat nipples and various ice puns. Even a film like Mallrats that openly discussed comics and superheroes was considered niche when compared to other independent films. Comic book publishers themselves were losing the faith of their readership and as a result pandered carelessly to what they thought their readers wanted, none worse so than the creation of the Marvel Swimsuit Specials. Marvel, today's biggest name in the superhero business, even had to file for bankruptcy in 1996. 

This is a far cry from today. Over the past fifteen years, superheroes have become an increasingly mainstream part of our collective culture. Besides several million (if not billion) dollar box office successes, more TV adaptations are finding their way to networks and even streaming services like Netflix. Movie studios, networks and audiences alike seem more thirsty than ever for superheroes. Even the once dying comic-book industry grew to a record $935 million in North America by the end of 2014.

Still, 2016 may indeed be the litmus test for another important point in the history of superheroes. This year marks the beginning of a serious uptick in the number of superhero movies Hollywood will be pumping out, leaving many to question their long-term viability. Last year Stephen Spielberg reiterated his thoughts on how their over-abundance will lead to a collapse not unlike the "Western."

There most likely will always be a portion of fervent fans ready to see the characters they once thought isolated to a comic book brought to the big screen. What's more difficult to predict is how general audiences - particularly worldwide - will react to an ever increasingly amount of such films. So far they have voted with their wallets to support the likes of Disney's Marvel Cinematic Universe (The AvengersGuardians of the Galaxy, etc.), Fox's X-Men films, and Warner Brother's budding D.C. universe (Man of Steel).  

These studios collectively released 15 superhero films between 2012 and the end of 2015. Audiences are looking at 23 more adaptations between 2016 and 2019. As Comic Alliance's graphic showcases, no studio seems to have any intention of slowing down now or, as Disney C.E.O. Bob Iger says, ever.

  

(Note: Fantastic Four 2 has since been "quietly" cancelled and Gambit is likely to release 2017 instead.)

Such characters indeed have more of a fanbase then they have ever had, but it wasn't their support alone that yielded the lucrative worldwide returns that really perked studios' attention. It's no coincidence that an entire sequence of Avengers: Age of Ultron took place in Seoul and that Iron Man 3 had scenes filmed only for the Chinese theatrical release. China's ever growing box office, as well as worldwide audiences' affinity for superhero movies, has been a huge factor in studios' decision making.  

Even if these films start to lose their resonance with domestic moviegoers and critics alike, they may not fade away like many would think. To the dismay of many, diminishing domestic returns haven't been enough to topple the Transformers franchise; each one has done better than the last in foreign markets and unsurprisingly the franchise is set to continue

Fortunately, for comic-book fans and general audiences alike, many of the superhero adaptations of recent years have largely avoided devolving into cheap "cash-ins" and been predominately entertaining films -- barring a few exceptions. These cases provide a glimpse into how such studios react to diminishing returns.  

After the release of The Amazing Spiderman 2, it became increasingly evident that Sony Pictures stood to make less and less on every subsequent Spiderman film. At the time Sony, like it's competitors, had an expanded slate of spin offs and sequels planned. Yet with the writing clearly on the wall, the studio made a deal with Disney's Marvel Studios to have the character join their far more "financially solvent" continuity; meanwhile, they quietly canned many of their previous projects. Similarly, Fox discreetly changed Fantastic Four 2's release date to T.B.A. (a not so subtle way of canceling it) after the first one flopped. All remaining three - Disney, Fox, and Warner Brothers - will most likely scale back in similar fashion should their films tank one after another at the box office.  

The increased importance of international audiences makes the future of super hero films far less predictable. Forecasting the "end of the superhero film," however, may be predicated on the notion that every superhero film of the past - and next - few years is and will be seen by moviegoers as being of one narrowly defined genre. There are certainly apparent similarities, namely that they all point towards Marvel's or D.C.'s comic books as source material. To assume they're all identical would downplay the wide range in storytelling that exists from at least 50 years worth of turnover in writers, artists, and characters.

Many "superhero stories" do have a comparable premise: protagonist - who is very often struggling against adversity of some kind - defies the odds and bests an antagonist. However, one could argue that it is hardly unique, as it is a common setup used in countless works of fiction. Even the superhero adaptations of recent years that have used such a "skeleton" have had a noticeable amount of tonal and genre diversity.  Marvel's films have taken a lighter tone but have also experimented with the conventions of period films, fantasy movies, science fiction, spy thrillers, and heist films. D.C.'s Man of Steel, and seemingly the upcoming Batman vs. Superman, are distinctly darker and more serious. Deadpool - the first of many superhero films this year - is based on the title character that blatantly disregards and often parodies what many think of as the conventions of "superhero stories". Having this kind of diversification will help keep superhero adaptations fresh to comic-book fans and audiences alike.