Wes Craven says keeping the plot of 'Scream 4' under wraps was "spy work".

The director has returned to the helm of the franchise - which stars Neve Campbell, Courteney Cox and David Arquette - for the fourth time and admits casting the movie was tough because he refused to let anyone auditioning see the actual script that would be used in the film.

He said: "Keeping things secret was spy work. We did things like, when we did our original casting, with hundreds of young actors reading script pages, we couldn't have them read pages from the actual script, so we had them reading pages from 'Scream 1', which was bizarre. I don't think we ever read actors with the actual pages from The Script.

"There were a lot of things like that that, which were annoying, but necessary to keep things secret."

Wes believes the reason why the film franchise has been so successful is that they break all the traditional rules and conventions of the horror genre.

He explained: "I think the very essence of the 'Scream' films is that we break the rules. We establish or state what the rules are, and then we immediately break them. That started in 'Scream 1', when they said, 'If you say, "I'll be right back," you'll die,' and the person that says that is one of The Killers. They said, 'If you have sex you'll die,' and Neve's character has the first sexual encounter of her life, and she's one of the survivors.

"We like to establish what the rules are, but they're really the cliches. As soon as they're stated in the Scream films, we almost always break them. It makes the audience not know what to expect next. If they think they know what the rules are, we immediately say, 'No, you don't.' "