Malcolm McDowell is perhaps the most enthusiastic of the several Hollywood actors lending their voices to the upcoming fantasy video game Elder Scrolls Online. He is convinced, for example, that his character, a demonic god by the name of Molag Bal (''Little Mol'', for short) has a softer side. So much so that he has infused his performance with a faint trace of vulnerability. ''I hope people understand that Little Mol is really sweet underneath it all,'' he says.

The ease with which McDowell took to the role has a lot to do with the fact that he has done this kind of thing before. As well as the diverse range of film, television and music projects he has been involved in over the years, McDowell has also voiced characters in bestselling video games such as Fallout 3, Killzone 3 and God of War III. He is not alone: he is joined in Elder Scrolls Online by John Cleese, Michael Gambon, Kate Beckinsale, Alfred Molina, Bill Nighy and Lynda Carter.

It is not the first time any of these actors have worked on a game. But while it's common for a game to feature one or two well-known actors, a cast of this size and collective talent is rare.

The video game industry's ties to Hollywood have, until very recently, been noticeably one-sided. For many years, Hollywood has tried to cash in on the growing popularity and mainstream success of games, by churning out films inspired by some of gaming's biggest intellectual properties, often with dismal results: Resident Evil, Tomb Raider, Prince of Persia, Street Fighter, Mortal Kombat and Doom are among the most famous examples.

Now, games are borrowing back. Makers of big-budget gaming franchises such as Elder Scrolls, Call of Duty and Grand Theft Auto – games that routinely cost $100 million or more to make and bring in sales well over that amount – are increasingly turning to established actors, scriptwriters and composers in an effort to improve the quality and commercial appeal of their games.

Last year, video game publisher Activision hired Oscar-winning scriptwriter Stephen Gaghan (Traffic, Syriana) to write the script for the recently released Call of Duty: Ghosts. Gaghan was already a fan of the franchise before he signed on, telling Empire magazine last November he relished the chance to work on the kind of ''all-hands-on-deck'' project that's so rare in Hollywood.

''The movie business has been in enormous flux,'' Gaghan told the magazine. ''The average development time for a Hollywood movie is nine years, [and] a lot of what you do is abstract. This is totally different.''

Publishers who court Hollywood talent for their games are often seen to be doing so only for publicity reasons: recognisable names on the box help sell more copies. But both industries are beginning to recognise they have a lot to gain from working together. When Gaghan agreed to write Call of Duty: Ghosts, he said he was interested in the idea of video games progressing to a level where they could feel as compelling as a film.

Two years ago, French game designer David Cage asked Hollywood actors Ellen Page and Willem Dafoe to star in his PlayStation 3 game, Beyond: Two Souls. Cage said in interviews at the time he didn't want Page and Dafoe for their popularity; instead, he was convinced their talents would lend an emotional depth rarely seen in interactive entertainment. He was right: Page and Dafoe's performances had a lot to do with the game's critical success.

When Zenimax Online, the studio behind Elder Scrolls Online, put out a press release revealing the list of talent it had hired to voice its upcoming game, the news made headlines on gaming sites around the world. Elder Scrolls has a large and devoted fanbase: the new game is the latest in a franchise spanning 20 years and almost as many games, including the 2011 hit, The Elder Scrolls V: Skyrim.

''Having someone like John Cleese in your game is good for PR purposes sure, but the point is he's astoundingly good,'' said Matt Firor, game director at Zenimax Online. ''Interacting with his character is one of the highlights of the entire game. So it goes both ways.''

Actors also appear to be taking on video game work for reasons other than an easy pay cheque. Bill Nighy joked that he liked voicing game characters because it takes a relatively short amount of time compared to a film role. But, he added: ''I like the variety of the things you have to achieve vocally [in a game].''

The growing interest in games may also stem from the new generation of actors, writers and filmmakers working in Hollywood, for whom games are as dominant and influential as other art forms. Several years ago, feature animated filmmaker Andrew Dayton convinced five of his colleagues at a prominent Hollywood animation studio to start making video games on the side. ''We all grew up playing games,'' Dayton said, ''so we're as passionate about them as we are films.''

Neither Dayton nor anyone else at Steel Wool Games had ever made a game before, but their collective expertise in animation was sufficient to provide them with at least one worthy idea: a quirky game about a spaceship janitor who hunts giant flies. ''Films have 85 to 120 minutes to tell a complete story. But the gaming world is completely open. You can create small games [or] you can create giant worlds that take hundreds of hours to explore,'' Dayton says.

Increased collaboration between Hollywood and the games industry can also lead to new, cross-platform experiences. Last year, US television network Syfy premiered a series created in tandem with an open-world massively multiplayer online game. The show and the game, both called Defiance, fed off one another, their storylines intertwining as the weeks went on.

Composer Stephen Barton, whose film credits include Kingdom of Heaven, Man on Fire, Gone, Baby, Gone and the Shrek and Chronicles of Narnia films, recently wrote the score for a first-person shooter, Titanfall. Barton, 31, says the current generation that drives Hollywood is accustomed to thinking about games as just another medium, not somehow ''beneath'' film or television. Which is why the partnership between Hollywood and the video game industry is only going to get stronger.

''A veritable gold mine awaits to whoever figures out how to marry the two mediums in a truly innovative way,'' he says.