Unfortunately out of print, Mabley’s seminal book can be found with a bit of patience from online booksellers and in a few libraries. It was Frank Daniel’s [renowned screenwriting teacher at Columbia University] main theoretical reference and as soon as I managed to find a second-hand copy, it became one of mine.
Mabley succinctly introduces all the classical tools, including the protagonist–goal–obstacles–conflict device, the dramatic three-act structure, its fractal aspect in scenes and sequences (the foundation for Daniel’s famous Sequence Approach), dramatic irony, surprise, mystery, theme, characterisation and unity as well as preparation and less structural tools like activity, dialogue, exposition or effects. He also offers a detailed analysis of more than twenty theatre plays and one film, Citizen Kane.
Mabley greatly influenced the study of dramatic writing and his ideas, rooted all the way back to Aristotle’s Poetics, were relayed and built upon by many teachers and theoreticians.