Seann William Scott, Jason Biggs and Eugene Levy have signed to star in 'American Pie 4'.

Care is needed if you want to gather together all the elements of the classic epics ever made and turn it into a spoof.

Spoofs of well-worn standards - horrors, westerns, musicals, spies - are difficult to pull off since they become, by their very nature, spoofs in themselves.

The most filmed story in Hollywood history is - wait for it - Cinderella, in its many forms; put-upon girl is treated badly by cruel step-mother and awful step-sisters but along comes her Prince Charming and the world’s a better place.