Billionaire genius Tony Stark had to learn to play well with others in "The Avengers" after two "Iron Man" films where he was the main attraction.
So did Robert Downey Jr., though his path to superhero team player came without the fisticuffs and rivalries that Stark stumbles into with his fellow Avengers, who beat up on one another a bit before they figure out how to work as a group.
Downey's had a long time to get ready for something beyond his close-up in the solo outings as Stark, the Marvel Comics superhero in a metal suit. The idea that Downey would become part of an ensemble of heroes was teased at the end of the first "Iron Man," with "Avengers" producer and Marvel Studios boss Kevin Feige steering such follow-ups as "Thor" and "Captain America: The First Avenger" toward that aim.
"I had five years to prepare myself, because Kevin Feige and the Marvel team had been saying that it was kind of heading toward this," Downey said.
Opening in the United States on May 4 and a week earlier in some overseas markets, "The Avengers" casts Samuel L. Jackson as Nick Fury, head of peacekeeping agency S.H.I.E.L.D., which rounds up a dream team of good guys (Downey's Iron Man, Scarlett Johansson's Black Widow, Chris Hemsworth's Thor, Chris Evans' Captain America, Mark Ruffalo's Incredible Hulk and Jeremy Renner's Hawkeye) to battle Thor's evil brother (Tom Hiddleston), who plots to subjugate humanity.
While it's an all-star cast, Downey's the mega-star. But unlike the diva moments among Stark and some of the other alpha dogs of the Avengers, there was no big-footing among the performers, according to the actors and director Joss Whedon.
Adjusting to ensemble life simply continued the path on which Stark and his healthy ego have been all along, Downey said.
"Personally, the `Iron Man' series so far has always been about making space for others and collaborating," Downey said. "It's Tony's quote-unquote story, but it's always about all the folks we get around him who are kind of what make him interesting or give him someone or something to fight."
Stitching together so many characters and story-lines could have turned into herding cats, but the communal structure meant no single actor had to carry the action all of the time.
Everyone took turns at center stage, and each got to take welcome breathers during the long shoot, Downey said.
"It was like a complicated pregnancy," Downey said. "What was fun, this bit of WWE superhero tag-team wrestling, is where Hemsworth's all beat up and he's been shooting nights, and my character's got the helmet closed, so I'm not there. Then he's flying home to be with the missus, and I'm coming in to do a bunch of scenes with Ruffalo. I think everybody really bought into the spirit of the thing."
Downey, 47, is preparing to shoot "Iron Man 3," which is due in theaters in May 2013. The film reunites Downey with his "Kiss Kiss Bang Bang" director Shane Black.
He won't disclose details, but Downey said the next installment is a "sort of storytelling that's really in Shane's wheelhouse, which is it doesn't need to be quite as linear, and Tony definitely is brought out of his comfort zone. So there's a lot of travel in this."
A third "Sherlock Holmes" movie also is in the works, with Downey's great detective expected to travel to North America this time.
Amid his two film franchises, Downey's busy with a newborn son with his wife, producer Susan Downey, with whom he has formed a film production company.
It's uncertain whether Downey will be back as Stark after "Iron Man 3," either in another solo film or a second "Avengers" tale. With his fourth Marvel flick getting under way, though, Downey said he feels he has a vested interest in the superhero business.
"It's dumb not to be open to possibilities, you know?" Downey said. "I kind of almost feel like a shareholder in the company, even sometimes more than an actor in the movies."