The duties of Hollywood stars these days extend well beyond simply acting and publicising their latest blockbuster movie.

Actors are now taking a more active role in bringing to life their characters in video game spin-offs.

Harry Potter is one franchise in which the wunderkind has been busy sprinkling his magic beyond books and the silver screen.

Most actors lend their voices to avatars to preserve authenticity, and possibly to fulfil the terms of their own contracts.

But five years ago, the original title Grand Theft Auto: Vice City managed to get Hollywood’s Ray Liotta to voice the protagonist.

Another game with no film legacy - but which benefited from a celebrity’s touch - is the latest instalment of the Call of Duty franchise.

A so-called "first-person shooter"game released last year saw Kiefer Sutherland voice the part of an army commander, while actor Gary Oldman took on another character.

This growing trend is a sign that the world of video gaming is starting to enter the mainstream.

This success is partly down to the popularity of games consoles such as Nintendo Wii which have all sorts of people waving their arms around.

Jesse Divinch, a research analyst at Electronic Entertainment Design and Research (Eedar), said the gaming industry has grown up over the last couple of years.

"Now we’re reaching a mass critical point where video games are just a device for males aged 18 to 35, he said, "video games are now for everybody".

But gaming for actors now means a chance to play their part at the vanguard of popular entertainment.

Rogue Warrior, a forthcoming first-person shooter, stars Oscar nominee Mickey Rourke playing the potty-mouthed Navy Seal Dick Marcinko.

But Mickey Rourke believes movies and games are still two distinct genres.

"I don’t really think people yet are comparing the two, insofar as somebody’s performance in a videogame as opposed to a feature film," he explained.

But film star Eliza Dushku, who plays Rubi Malone in the upcoming game Wet, believes it is de rigueur to be in with the gaming fraternity.

"Videogames have almost become acceptable and cool for grown ups - not for people who are just in their teens," she said.

She added that gaming was now accepted as a hobby.

"I know so many people - friends, actors, directors - who are older and used to maybe play in private, but who can now say it loud and proud."

There is also some kudos for actors playing a cool video game character, as gaming research analyst Michael Pachter explained.

"Actors play games and it’s almost bragging rights to say to their friends ’I was voice in that game’," he said.

Another attraction for the likes of Beyonce is the fact that marketing men can offer good financial rewards thanks to individual titles selling more than ever.

The public can also identify with celebrities, and seeing them playing games acts as an influence, according to Mr Divinch.

"These are people that we follow; we know their likes, we know their dislikes," he said, "so when we see them play these games, they do have an influence over us in the very same sense that our peers have influence over us."

But in the grand scheme of Tinseltown, the involvement of A-listers in games is still fairly small.

As Mickey Rourke put it, "The fact is when I go out and see another actor we’re not going to talk about video games."