As the biggest comic book publisher in the world, Marvel has their hands in everything from film, merchandise, video games, film, and television. Arguably, there has never been a more bountiful time for superhero movies than in the last decade or so, with the release of a litany of films like Guardians of the Galaxy, Iron Man, Thor, Wonder Woman, and Watchmen. Many of these films have received critical acclaim also, The Dark Knight films being an obvious example from DC. Films like Black Panther, The Avengers, and Spider-Man: Homecoming have also made an impact.

Being at the top of the comic book world as part of a booming industry that’s never been bigger, major studios are very wary of their reputation. Actors that take a leading role in these films are either A-listers or become A-listers soon after the films released, giving them a huge amount of public exposure and, by extension, susceptibility to public scrutiny. Fans of comic books and comic book movies tend to be, shall we say, among the most dedicated. So actors have to be careful of what they say about their roles and their films to keep the directors, writers, and producers happy. Add the long hours, make-up, and rigorous training regimes that come with these roles too, and let’s look at how these actors sacrifice some freedom for their fame.

25 Don't Work With The Enemy

In a Supernova Comic-Con convention in Sydney, Australia in 2017, Chris Hemsworth, who played buff blonde Viking Thor in the 2011 Marvel film claimed that it is illegal for actors cast in Disney/Marvel Studios movies to take roles in films for competing DC Films and Warner Bros. Studios. His claim has been challenged by various other actors working for Marvel Studios.

But it seems that the general feeling is that talent cross-pollination between both sets of companies is discouraged.

This would, of course, make sense, considering the fact that Marvel and DC are in direct competition with each other. It’s like Coke vs Pepsi, Burger King vs McDonald’s, Metallica vs. Megadeth (okay, maybe not that). So don’t expect Christian Bale to be cast as the next Iron Man anytime soon.

24 Loose Lips…

So remember what I said about comic book fans being dedicated? It’s great when a studio like Marvel releases a movie because they are basically guaranteed good box office numbers. However the flip side of that is that fans like to find out as much information about the upcoming movies starring their favorite superheroes, and now with the prevalence of the internet and social media, it's getting harder and harder for those involved in the films to keep a secret.

So, the solution is not to tell the actors anything about the plot until shooting begins! That’s exactly what happened on the set of the Avengers films, with actor Don Cheadle remarking that things changed in “real time,” keeping him “on his toes.” No pressure, man.

23 Secret Actors

Speaking of secrets, actors are not the only ones kept in the dark when it comes to major movie information. So are the fans.

And we’re not talking about potential spoilers here, we're talking about the identity of actors cast in specific roles.

As mentioned before, with the whole world now shrunk down and accessible via the smartphone in your pocket, secrecy is key to avoid major information being leaked to the public at large. A great example of this is the film Guardians of the Galaxy Vol. 2, where casted actor Michael Rosenbaum’s character was kept a secret. In the end, he went on to play laser beam-firing Martinex, that we know. Well, at least now we do!

22 Vetting

Keeping in line with the secret service-esque level of secrecy and security (or paranoia, depending on how you look at it), Marvel also subject their potential cast to background checks. Actor Tom Vaughan-Lawlor, who is to play villain Ebony Maw in the upcoming Avengers: Infinity War, spoke about the thorough vetting he went through during the casting process. Apparently “they do background checks” to make sure prospects aren’t, among many things, a monster. I don’t think Tom being white and bald necessarily qualifies him as such but, can’t be too careful, I suppose. He also spoke about contracts he had to sign which ensures he keeps tight-lipped about the film's plot. Somehow Hemsworth’s story seems slightly more plausible now…

21 I Am… Actually Iron Man…

In a fascinating case of art imitating life... imitating art again, we have this. Chosen to portray Iron Man in the 2008 film of the same name, Robert Downey Jr. was cast, in part, due to the similarities the actor shares in his real life with the fictional Tony Stark. According to the film’s director Jon Favreau, Downey Jr. "had to find an inner balance to overcome obstacles that went far beyond his career. That’s Tony Stark."

He also said that the actor could make Stark likable and could win over the audience, probably due to their shared arrogance and charm.

Even the montage which occurs in the film features real pictures of Downey Jr. and his actual father, meant to represent Stark’s father. Who needs method acting when you're living out your own life on the silver screen?

20 Creative Control Issues

Acclaimed actor Edward Norton played the role of Bruce Banner in the 2008 film rendition of the Hulk, and while it wasn’t that successful (at least by Marvel’s standards), he was set to reprise his role in the 2012 film The Avengers, which, even without Norton’s contribution, would go on to be a commercial and critical SMASH! (Get it?)

The reason for this down to a dispute between Norton and Marvel Studios. Norton, who expected a certain amount of creative control over his character, did a rewrite of writer Zak Penn’s draft. However, Marvel decided to make a “shorter, more action-packed” film, discarding much of the character development included in Norton’s rewrite. This fragment could not be resolved, and Norton was replaced by Mark Ruffalo. Did we mention Marvel’s penchant for creative control?

19 Authenticity

Not solely the studio putting pressure on its actors here but a combination of studio pressure and willing participation from its cast. Black Panther, this year's big Marvel box office hit, strove for authenticity in its re-creation of fictional Wakanda and its inhabitants.

The film contained an all-black cast, and lead Chadwick Boseman insisted on using an authentic African accent for the role.

This is because Wakanda, the fictional African nation in the Marvel universe in which Black Panther inhabits, was never colonized by European settlers. By doing all of the above, Boseman and all those involved with the movie strove for a level of authenticity that others studios may not have tried to achieve.

18 I Am Groot

You would be forgiven for thinking that Vin Diesel, who played the voice of character Groot in Guardians of the Galaxy, had the easiest acting job for a major Hollywood flick. I mean, all he had to do was say the words "I am Groot," as that’s all his character can say, right? Well, turns out it wasn’t quite that simple. According to Diesel himself, he had to say those three magic words over a thousand times to capture the feeling or nuance of any given scene.

Apparently, Diesel would walk into the recording booth and there was “a fifty-page document that on the left-hand side said ”I am Groot” and on the right-hand side… a paragraph or a sentence explaining what he really meant or what he was really trying to say.”

17 From The Top, People!

The epic fight scene is a quintessential element of the superhero genre, and the action genre in general, so when real-life behemoths Dave Bautista and Chris Pratt, who played Drax the Destroyer and Star-Lord respectively, were set to have their own duel, it was to be a showdown of epic proportions.

The two had rehearsed their fight scene for over two months before James Gunn decided he wanted to change it.

This gave the actors less than a day to learn their new choreography, taking the two actors twenty-two takes to nail it. Talk about last minute changes; you can’t help but feel sorry for Bautista and Pratt, who must’ve been at least somewhat miffed that all their previous preparation was for nothing.

16 Pulling A Stunt

Of course, these fight scenes are theatre, involving no actual hand to hand combat. But what about when an actor has to take part in a scene which poses a real-life risk of injury? Well, that’s what stunt doubles are for! With very high insurance premiums, Disney is keen to ensure the safety of their actors, as well as their bank accounts.

Brave men and women, like skateboarding daredevil William Spencer, who doubled for Spider-Man in The Amazing Spider-Man, or 59-year-old Tracey Eddon who doubled as Supergirl and recently worked on the film Doctor Strange, ensure that the men and women cast in the starring roles get to wow audiences in relative safety. And take all the credit for it, too.

15 Making Up A Beast

Landing the role of Drax the Destroyer was a huge break for Dave Bautista in the movie business, as the former WWE superstar found himself cast in one of the biggest blockbusters of 2014.

However, it wasn’t all glamorous, as Bautista had to undergo a long and arduous application of full-body make up daily.

David White, who was the special makeup effects designer on the film, recalls the five hour make up job as “a real slog for the team” due to its complexity. Also, a plastic mold was created in the exact shape of Bautista’s hulking physique, complete with prosthetics, extremely detailed character tattoos, and a multi-colored paint job. Hope he didn’t have to use the bathroom during the application!

14 Go Bald Or Go Home

On the subject of Guardians of the Galaxy and extreme makeovers, Karen Gillan, who plays the mega-villain Nebula engaged in a spot of method acting by shaving her head bald for the role.

Marvel studio boss Kevin Feige commended the dedication of the actress, saying it was “really, really cool that she was willing to do that”, also saying (truthfully) that Gillan “is beautiful with or without hair. To make the transformation all the more dramatic, at that year’s Comic-Con Gillan arrived donning a wig, only to reveal her bald head mid-convention, much to the surprise of those in attendance. The courageous feat was admired by Feige, as well as other members of the studio and, more than likely, most fans at the convention.

13 Press Tours

Promoting a film is part of the gig for actors in Hollywood, whether appearing on a television chat show or being interviewed for a periodical, actors are at least partly responsible for generating buzz and interest for their upcoming flick.

Many Marvel actors, but not all, are contractually obliged to partake in global press tours.

With a rabid fan base and a culture of conventions in the comic book world, Marvel actors know what the have to do to get as much exposure and positive press as possible, and that is by going to see these die-hard fanboys and girls. Again, these may be actors from different worlds and original scripts, but they draw their characters from comic books with extremely loyal and dedicated fan base.

12 Last Minute Cramming

Chadwick Boseman is here again for his role as the Black Panther, this time in the 2016 film Captain America: Civil War. Boseman was, admittedly, not a huge reader of the Black Panther or Marvel comic books, but when it came time for him to make his acting debut in the Marvel Universe, Boseman took it upon himself to do some, ahem, research by reading as many comic books as he possibly could. Knowing what we know so far about Marvel’s attention to detail and standards they place on their cast and crew, this was probably not a bad idea. Similar to the attention he paid to the accent in Black Panther, he also visited South Africa to better understand the character’s ethnic origins.

11 Helicopter Guns

In one of the most iconic scenes in the franchise, during Captain America: Civil War Chris Evans who plays the main man himself is filmed preventing a helicopter taking off with one arm.

His bulging biceps are a thing of over the top visual Superhero hyperbole.

The only thing is, that’s not CGI, those are actually Evans’ guns. In keeping with the tradition of actors packing on serious lean size for their roles, Director Anthony Russo swears that these shots were not enhanced, claiming that they “didn’t touch him, that’s all Chris Evans”. Apparently, all the crew gathered around the set during the filming of the scene, none able to believe the actual size of the actor's behemoth biceps. Take-off delayed.

10 Time To Hit The Gym

Superheroes are meant to be larger than life, and now more than ever actors cast to play our favorite crime fighters and villains are expected to pack on serious lean muscle mass for a role. There are many examples of this in the Marvel canon and many examples of actors who hated the process.

Chris Hemsworth, the aforementioned herculean Thor, was so dissatisfied with the rigorous training and diet regime that he underwent for Thor that he had a dispute with the studio over undergoing it again for the Dark World sequel. Another actor who was less than taken with the weight training and diet was Captain America himself, Chris Evans, who would apparently try to find excuses not to undergo the intense workouts he needed to build his superhero physique.

9 The Way Of The Fist

Lifting weights is not the only type of training actors are encouraged to do for these roles. These superheroes may be jacked, but they’re also supposed to be able to fight. Y’know, to fight crime. Robert Downey Jr. trained in Wing Chun, the Chinese martial art developed by Bruce Lee, to help him get further into the mindset of the evil vanquishing Iron Man.

Apparently, his Wing Chun training also helped Downey Jr. to fight his own battle with substances, which is, of course, a good thing.

In addition to doing martial arts, Downey Jr. also incorporated weight training into his routine. Because the ability to fight crime is comparable to the ability to look good with no shirt on, apparently.

8 Big Shoes For A Small Role

Vetting is not strictly limited to background checks for actors, it also pertains to the hiring process. For Ant-Man, the 2015 summer blockbuster, there was a long, long list of actors who could’ve possibly played the tiny hero.

One of these actors is Joseph Gordon-Levitt, who early on in his career became known for his role as Tommy Solomon in 3rd Rock from the Sun but whose recently become a Hollywood darling and, curiously, played John Blake in The Dark Knight Rises. Eventually, however, the role went to Paul Rudd, known for his prominent roles in Friends, Anchorman and Forgetting Sarah Marshall, among others. However, passing up an actor like Levitt could not have been a decision taken lightly by Marvel, who clearly have a distinct vision for who they want to play in what roles.

7 Shoot It Again

Reshoots happen in movies. Sometimes when a film is put together, glaring problems and faults can come to light in the clarity of post-production. Marvel, like many other things on this list, take it a step further, looking at reshoots as not a necessary evil, but an important and integral part of the filming process.

Kevin Feige has referred to the process as “invaluable”, and not just there to fix something that’s not right.

Instead, he uses the process because “sometimes a better or more exciting idea will come along”, or to trim the fat off a particular scene or character (just as Mickey Rourke). Declaring post-production as his favorite part of the process, he proudly recalls a “three continent shot” from Thor: The Dark World, where three actors in three different continents appear in the same scene.

6 Tough Schedule

On the subject of retakes, this one's a doozy. Idris Elba is no exception when it comes to Marvel's rigorous reshoots or contract commitments. Elba, who played Heimdall in both Thor and Thor: The Dark World, was contractually obliged to make a cameo appearance in the Avengers: Age of Ultron flick.

The main issue is that Elba was DJing in Ibiza at the time, and had to travel to film his cameo. On set, his co-stars Tom Hiddleston and Chris Hemsworth jokingly asked him if he was not supposed to be in Ibiza. This lead to, in his own words, some poor performances and a drop in quality in his sets. Pulling someone in to fulfill a contractual agreement while trying to fulfill other ones must be a balancing act. Or a “hybrid,” as Elba refers to it himself.