The One Word Benedict Cumberbatch Improvised In Avengers: Infinity War That Changed Doctor Strange Forever

Being a superhero is hard work — being an actor playing a superhero can be even harder. Okay, maybe not, but with so many superhero movies vying for attention on the big screen, it can be a challenge for an actor to make their character stand out above the rest. 

Robert Downey Jr. gave Iron Man his snark. Chris Evans gave Captain America his nobility. Tom Holland gave Spider-Man his geeky charm. And when English actor Benedict Cumberbatch was brought into the MCU to play the magic-wielding powerhouse known as Doctor Strange, you can bet that Disney and Marvel considered the casting choice a risky one. At the time, Cumberbatch had a niche following of fans with the BBC series, "Sherlock," but had not yet reached what one might call A-list status. 

In the end, the choice paid off, and the first "Doctor Strange" film made its mark on the MCU, as a hit with both fans and critics (via Rotten Tomatoes). Soon afterward, his mystical character was brought deeper into the fold with the release of "Avengers: Infinity War," the blockbuster film that brought many heroes of the MCU together for the first time, Strange included. Surrounded by so many established MCU actors may have been a bit intimidating for Cumberbatch, but once he found his footing, he wasn't afraid to have a little fun with his co-stars. One such interaction came in the form of an improvised line that ended up in the final film, and no doubt left an impact on Strange's character development, going forward.

"Avengers: Infinity War" wasted no time in leaping right into the action, beginning with the cosmic warlord Thanos (Josh Brolin) wiping out many of the surviving Asgardians and launching an attack on Earth. After the Hulk (Mark Ruffalo) crashes into the Sanctum Sanctorum and announces Thanos's imminent arrival, Doctor Strange (Cumberbatch) crosses paths with Tony Stark (Downey). Their personalites clash, and the event inevitably turns into a clash of egos, with Stark asking Strange, "What is your job, exactly, besides making balloon animals?"

Strange's reply? "Protecting your reality, douchebag."

In an exclusive interview with The Hollywood Reporter, Cumberbatch admitted that he was the one who decided to spice up his character's line with the addition of "douchebag." 

"I remember on the set when I called him a douchebag, there was this sort of ripple effect," he said. "'Oh my God. Did you just call Iron Man a douchebag?' They kept it, good for them. And then, it got the same kind of response at the cinema. I was just ... I got bored of being compared to Liberace or whatever other retorts the guy with the same camp goatee had opposite me, so I tried to knock him down. It's great fun to play with that stuff. You find your feet. The more times you do it, the more familiar it becomes."

Because their personalities are so similar, it's no wonder that Strange and Stark would be at odds with one another. Yet the two actors have nothing but respect for one another off screen. "He's a really great leading man," Cumberbatch has said of Downey. "He's very generous."

Doctor Strange will next appear in "Spider-Man: No Way Home," which hits theaters on December 17.