The January courtroom battle between Warner Bros, which was the lead studio backing the new movie Watchmen, and Twentieth Century Fox, the studio which claimed it still had distribution rights to the property under a 1994 turnaround agreement with producer Larry Gordon, threatened to derail what promises to be one of the year's biggest openings this weekend.

The $130m movie, based on the beloved comic-book series, is also the latest directing effort from Zack Snyder, the man behind 300, which had a stunning $71m opening weekend in exactly the same weekend slot (March 9 to be precise) two years ago.

'I was nervous but always felt like cooler heads would prevail,' Snyder explains. 'Part of me thought it would be really cool if the movie got shelved for all time because the 20 people who had seen the film at the time could go on tours describing what it was like to people. But seriously, I was only briefly worried. Nobody ever called me to give testimony, so I just sat at home waiting for them to figure it out.'

Filming the unfilmable

The case was settled in mid-January, just seven weeks before the opening. It is perhaps no surprise Watchmen ended in such a tangled web of studios, having been tossed around between so many of them since rights to Alan Moore and Dave Gibbons' 1986 DC Comics series were snapped up by Gordon and Joel Silver for Fox in 1986. Numerous executives and film-makers subsequently deemed it unfilmable.

Fox put it into turnaround in 1991 (cementing that turnaround agreement three years later), before Gordon set it up at Warner Bros, Universal and Paramount respectively, all of which ultimately balked. Finally in 2005, Gordon and new producing partner Lloyd Levin returned to Warner, and Snyder - then still in production on 300 - became involved. Once he was on board, Paramount came back in as a financial partner and international distributor. Warner is handling domestic and Fox receives a healthy gross participation position under the recent settlement.

Whatever the legal wrangles, the key here is Snyder, an energetic 43-year-old who has become one of Hollywood's biggest directing names with just three movies under his belt. A highly successful former commercials director, Snyder's first two films, a remake of his boyhood favourite film Dawn Of The Dead (2004) and the movie of Frank Miller's graphic novel 300 (2006) together grossed nearly $600m worldwide. Terry Gilliam and Paul Greengrass, among others, had developed their own visions of Watchmen, but it was Snyder who was able to get his to the screen.

'This movie went through a lot of capable hands and I suppose it's surprising it ended up with me, but I love the material so I was honoured,' he says. 'I still have no idea what (Gilliam or Greengrass) proposed or what their plans were. I have great respect for them. I even make reference to (Gilliam's) Brazil in the credit sequence.'

Working with screenwriter Alex Tse and a previous screenplay by David Hayter, Snyder creates a dazzling world out of Moore and Gibbons' tale and the 163-minute film is bound to appeal not just to fans of the original series but also to the broad demographic that lapped up The Dark Knight last year.

Set-building in Canada

Shot in Vancouver on more than 200 specially built sets, Watchmen is the antithesis of 300 with its stylised green-screen storytelling technique. 'The exteriors in Antarctica and the Mars scenes are all green screen, but most of it is real sets,' he says. 'We built a giant New York City backlot in Canada. I shot about 1,000 commercials and Dawn Of The Dead with real sets and I would say I am more comfortable shooting that way. With this movie we combined every technique we could think of to make it work. We re-used sets 10 times, we did a bunch of crazy tricks, because it's pretty ambitious.'

Similarly, for all the technical challenges of these last two movies, he still shoots on film. 'I haven't been converted to the digital age yet, even though I do everything else,' he says. 'I don't want to say I'm a purist but I've always shot on film and it's my tool and I'm pretty comfortable with it.'

Like 300, he forsook any A-list star names for a cast of well-known character actors including Patrick Wilson, Jeffrey Dean Morgan, Matthew Goode, Billy Crudup and Jackie Earle Haley.

'The studio would have been happy if I'd gotten some big names in the movie, but on the other hand, I tried to cast each role as I would want to do it,' he says.

Although Snyder says 300 was more violent, Watchmen is certainly an R-rated film, with sex and gore aplenty. And the source material ensures it is also one of the most subversive superhero movies to date, with images of the superheroes shooting JFK, raping women and causing the deaths of millions of people.

Defying audience expectations

'Comic-book myths are now part of society,' says Snyder. 'People on the street are aware Peter Parker was bitten by a radioactive spider and that Batman is afraid of bats and his parents were murdered. They are also aware there are moral imperatives, like the fact the bad guy dies. The cool thing about Watchmen is that it does the exact opposite. It really says, 'What if''. Don't you think that if Superman were real, he would collect all the world leaders and make them behave or else kill them. He wouldn't spend his time getting cats out of trees. Watchmen takes on the reality of that kind of power.'

Snyder is also set to push the limits with his next film, Sucker Punch, which he says will go into production in the autumn. 'It's pretty crazy,' he says. 'I've always wanted to make an action movie with real crazy action in it and that's what we're working on.' Snyder wrote the screenplay, in which a girl fantasies about breaking out of an insane asylum, with Steve Shibuya.

He is also working on Guardians Of Ga'Hoole, a CG-animated family film now in production at Australian studio Animal Logic, which produced Happy Feet and also worked on 300 with Snyder. Both Sucker Punch and Guardians Of Ga'Hoole are at Warner Bros.