And one for all

LOS ANGELES – 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.

Downey’s had a long time to get ready for something beyond his 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.

Opening in the United States on Friday, “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).

While it’s an all-star cast, Downey’s the mega-star. But unlike the diva moments among Stark and some of the other 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 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.

“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.

A third “Sherlock Holmes” movie also is in the works.

It’s uncertain whether Downey will be back as Stark after “Iron Man 3.” 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.”