Legendary film director Alfred Hitchcock is quoted as saying: ‘To make a great movie, you need just three things: a great script, a great script and a great script.’ I like that quote for two reasons: One, it acknowledges the importance of a good screenplay. And two, in a world filled with auteurs, any director who openly values the work of the screenwriter is to be commended.

Still, I feel Hitchcock may have overstated the case. Great scripts aren’t handed out in cinemas for audiences to sit down and have a good read. Audiences come to watch a movie. For the leap from page to screen to happen successfully, other artists – everyone who works on a film – are required to do their best. Because a film is made three times: once when it’s written, once when it’s shot and once when it’s edited. Filmmaking is a chain of contributions with the end product only as strong as that initial link in the process – the screenplay.

Given the system, it’s easy to see how a good script could become a bad movie. All it requires is for one or more of the collaborators along the way to be miscast or to be doing less than their best work. But one would be very hard pressed to name a good movie made from a bad script. If the screenplay isn’t there, all the rest is camera angles and set decoration.

So what makes a good screenplay? In his book on writing, Aspects of the Novel (1927), novelist E. M.  Forster (A Passage to India, Room with a View) sums up the appeal of all narratives: ‘It has only one merit: that of making the audience want to know what happens next. And conversely it can only have one fault: that of making the audience not want to know what happens next.’ That’s it. That’s the bottom line for all storytelling. Either you want to know what happens next or you don’t.

Join George Merryman for his Writing for the Screen course, running over six Tuesday evenings commencing 22 July.