Who cares who's playing the lead?

The latest incarnation of A Nightmare on Elm Street sees Robert Englund ditched from the Freddy Krueger role that he has become synonymous with and replaced by Jackie Earle Haley. Changing the actor playing a famous character has become the vogue in Hollywood, where studios will try anything to keep a franchise going, and this is a trend that actually seems to be finding favour with the movie-going public.

Jackie Earle Haley's career has had something of a renaissance ever since he chilled as a convicted sex offender in Little Children opposite Kate Winslet in 2006. He seems a perfectly good candidate to play the famous horror candidate, yet there is a sense of sacrilege that Englund has been ditched. Movie fan site Ain't It Cool News captured the mood of the public when it posited: "Once one looks beyond the 'Freddy Isn't Robert Englund!' prejudice... this isn't altogether unreasonable casting at all."

The phenomenon of actors bringing new life to a character is something that has always been apparent in theatre, and in movies it has always been fair game to do it for well-known characters adapted from other mediums, such as comic books and plays, but there has for a long time been a sense that, if an actor gets too old to play a part that he made famous on screen, then the character should be retired too. William Shatner as Captain James T Kirk was once the prime example of this.

It used to be that audiences would only be able to argue over which James Bond was the best. He was the cinema character where it seemed fun to compare, and which actor one preferred as Bond said a lot about an audience members' taste and age. It was helped by the fact that the Bond stories usually worked as stand-alone films with separate narratives. Yet this did create the bizarre situation in 1983 when both Octopussy, starring Roger Moore, and Never Say Never Again, with Sean Connery, were released within months of each other.

Now though, it's not just James Bond who has had as many face-changes as Doctor Who. With the increasing number of remakes, reboots and sequels that seem to appear in every passing year, cinema audiences are getting more used to casting changes. It's also the clearest sign that, over the past decade, actors have become less important in terms of getting bums on seats.

In the eight years from Tim Burton's Batman in 1989 until 1997's Batman and Robin, Michael Keaton, Val Kilmer and George Clooney all donned the tights without the merest hint of a "holy cow" from Robin. When Ang Lee's Hulk starring Erik Bana didn't live up to box-office expectations in 2003, the studio tried again five years later with Ed Norton in the title role trying to give the franchise a new lease of life. It has become the ready-made excuse for producers when a franchise fails, to blame the actor, rather than the product or themselves for failure.

Actors are not yet completely defunct, as the right actor in the right role can still make it difficult for a franchise to replace them. For example, when Matt Damon announced that he was following the lead of Paul Greengrass and refusing to do another Bourne movie, it seemed to signal the end of the franchise, despite Bourne often being referred to as the American Bond.

The caveat is that studios have become rather adept at keeping franchises going through the phenomenon of the reboot. A reboot is the restarting of a franchise from the beginning. Sam Raimi and Tobey Maguire's decision not to do another Spider-Man movie wasn't met with tears in the Sony studio office but the drawing up of a plan of how to reboot the webbed crusader. Similar soundbites have been made about Bourne, where it has been suggested that the plot will revolve around his younger years.

Last year, JJ Abrams did a remarkable job with his reboot of Star Trek, successfully managing both to replace the seemingly irreplaceable William Shatner as James T Kirk with Chris Pine and also finding space for both the original Spock, Leonard Nimoy, to line up next to his new doppelganger Zachary Quinto.

Star Trek was the prime example of a franchise that had previously tried not to replace iconic characters with new characters. Instead of reboots, they had spin-offs such as Star Trek: The Next Generation with all-new characters, as it seemed foolhardy and impossible to replace Shatner as Captain Kirk. Yet modern audiences seem happier than ever to make this jump. Christopher Nolan's Batman reboot saw Christopher Bale don the cape and Bale has also been in an attempt to keep the Terminator franchise going long after Arnold Schwarzenegger showed that he would not necessarily be back.

Occasionally the death of an actor, such as that of Heath Ledger, will result in the need for a casting change. And this was one aspect that director Terry Gilliam successfully negotiated in The Imaginarium of Doctor Parnassus, even creating a light-hearted moment when Johnny Depp seems shocked as he purveys his own reflection and the character seems surprised not to look like Ledger. Another tool being used by studios is through the use of "synthespians", short for synthetic thespians. These are artificial actors created on the desk of a special-effects boffin. James Cameron has already suggested that the technology used in Avatar could be used to bring actors back to the screen long after they have died. Indeed, Avatar itself takes a step in that direction.

One obvious advantage for studios of the diminishing role of the actor is that actors have become cheaper to employ. In the end, whether an actor reprises a role often comes down to money, but if audiences don't care if the face changes the bargaining position of the actor is severely weakened.

However, audiences still seem to prefer to see the same actors play characters, which is why studios now take so much care to usually option actors for three movies when they think they might have a franchise on their hands. Given the changing nature of actors it's amazing that the principal actors of the Harry Potter franchise will have stayed together through eight movies.

It's not just blockbusters that have taken advantage of this phenomenon. When Todd Solondz decided to make a sequel to his 1998 hit Happiness, he abandoned the usual convention of asking the same actors to reprise their roles. Instead, in his follow-up Life During Wartime, he started the casting process from scratch. Solondz has a history of doing this sort of thing. In his last outing, Palindromes, he employed eight different actors to play the 13- year-old girl who is determined to enter motherhood.

The rationale, as explained by Solondz then, was that he wanted each young actress to portray a different aspect of the main character's personality, so someone different would play Aviva when she was happy to the girl who would play her when she was sad. It's also extremely plausible to argue that young actresses only have a limited range, and so multiple casting of the same role is helpful rather than being a hindrance.

For actors outside of childhood this could perhaps be taken as a dismissal of their ability, although Todd Haynes did successfully tread this very line in his Dylan biopic I'm Not There, where he also used the alternative-actor ruse to show different aspects of his main protagonist's personality.

However, to dismiss Solondz's casting as a gimmick is to miss the point that, rather than looking at actors as mere pawns, the bespectacled director is showing that different actors elicit different reactions from the audience, even if they are playing the same part or acting out very similar scenes. Each actor brings something unique to the party and, as such, becomes more, rather than less, important because of the interchange.

Of course, some could also argue that Solondz recast because of financial constraints and an inability to recast the same actors. Getting Hoffman back to play a role that may have offended some of his post-Oscar fan-base would have been extremely difficult no matter how much money was on the table. Instead Solondz found a way, taking the lead from blockbuster movies, to make a sequel without breaking tight budgetary constraints.

Likewise, the team behind A Nightmare on Elm Street have made a marketing splash about the fact that a new actor is playing Freddy, and it has become the big reason why this reboot should be seen.

'A Nightmare on Elm Street' is released in the UK on May 7