Robert Downey Jr takes on Niko this week as Hollywood and the video-games industry fight an unprecedented battle for spending on entertainment.

In one corner is Niko, the anti-hero of Grand Theft Auto IV, the latest instalment in the blockbuster video-game franchise that could break industry records when it is released on Tuesday.

In the other corner is Downey in Iron Man, a comic-book adaptation expected to become Hollywood's first big summer hit when it opens on Friday.

The contest has reignited the argument over whether video games have gained ascendancy with consumers over films.

John Riccitiello, chief executive of Electronic Arts (NASDAQ: ERTS - News) , the world's biggest video-games publisher that has bid $2bn for Take Two, publisher of GTA IV, says movie executives have told him they fear the game could "kill" Iron Man. "I don't think I've ever heard of that before," he says. "There's a big reset happening now."

Yet, hopes are high in Hollywood that Iron Man could score one of the biggest May openings, regardless of the success of GTA IV. "The forecasts range [from] $50m to $100m for its opening weekend," says Paul Dergara­bedian, chief executive of Media by Numbers, which tracks the box office performance of films.

Moreover, Mr Dergarabedian thinks the release of GTA IV could help the performance of Iron Man, because "gamers buying GTA IV are going to be talking about the game and they're going to be talking about the movies and the movie they will be talking about is Iron Man".

Geoff Ammer, president of worldwide marketing and home entertainment for Marvel Studios, says the company appreciates "EA's enthusiasm" for the release of GTA IV. "The two properties can co-exist in the marketplace," he says. "We believe that moviegoers will make going to see Iron Man part of their weekend plans."

Grand Theft Auto is the biggest franchise in the games industry and its latest version could sell 6m units in its first week, according to Edward Woo, an analyst at Wedbush Morgan Securities.

The figures would eclipse last year's release of Halo 3 by Microsoft and at $60 a game and $90 for a special edition, revenues of close to $400m are expected in the first few days.

"In entertainment dollars, that means less money for people to go and watch a movie," Mr Woo says.