One of the first and probably most important jobs for the director of a play is to choose a cast. Choices that are made will heavily depend on the look and feel that the director wants for the production of the play. Priestley is specific in the stage directions about each character’s age, appearance and manner.
For An Inspector Calls to work on stage it is vital that all cast members work well together. They would all need to understand one another, delivering their lines with pace - especially as the tension of the play increases. It would also be important for the change in characters like Sheila and Eric to be clear as the play progresses.
One of the most important casting choices would have been who would play the Inspector and how they would portray him. In the stage directions he is described as follows:
The Inspector need not be a big man but he creates at once an impression of massiveness, solidity and purposefulness. He is a man in his fifties, dressed in a plain darkish suit of the period. He speaks carefully, weightily, and has a disconcerting habit of looking hard at the person he addresses before actually speaking.Priestley introduces the Inspector Goole character
It would be up to the director whether or not they would stick to this interpretation of the Inspector. It might be interesting to have a younger Inspector- that could shed a different light on the themes of the play. Some versions of the Inspector are very confrontational, taking charge and shouting their accusations at the Birlings. Other interpretations have been softer, more sympathetic. Each interpretation would completely change the tone of the performance. Have a look at the following clip. Which interpretation do you prefer? How would you cast the Inspector?