The Art of Dramatic Writing is a book from the 1940s about how to write drama, preferably drama with a tragic bent. It’s also a book much referred-to in Lee Sheldon’s Character Development and Storytelling for Games, which is the reason I write about it now.
Egri has one central thesis that animates all his observations about craft, structure, and execution. This is appropriate, because his central thesis… is that a play should have a central thesis.
(Egri uses the word “premise” rather than thesis, but what he means is what we tend to call a thesis statement now, rather than a sitcom-style premise about starting conditions.)
These premises tend to be simple statements about cause and effect, and many of the examples he analyzes are demonstrating those effects in tragic form. For example:
Sacrificial love conquers hopelessness.
Ruthless ambition leads to its own destruction.
Escape from reality leads to a day of reckoning.
He who digs a pit for others falls into it himself.
You can arrive at your premise [or thesis] in any of a great many ways. You may start with an idea which you at once convert to a premise, or you may develop a situation first and see that it has potentialities which need only the right premise to give them meaning and suggest an end. (22, in the edition linked above)
Essentially everything else in the book is analysis and application of this idea. Characters should be constructed so as to make them proof-cases for the thesis. The environment of the story must set a stage for a conflict that will show the thesis playing out. Situations, plot, causality must all serve the thesis.
At first blush this might not seem particularly useful grounding for 21st-century interactive storytelling. That’s partly because of the time it comes from: its examples are all stage plays and all old; its ideas about characterization partake of the sexism, racism, and classism of its era. But also there are the structural considerations. Egri’s book emphasizes an idea of inevitability, a story construction in which everything works toward the main character making a decision that executes the thesis. On a naive reading, that might seem to be at odds with the whole concept of interactive story. From another perspective, Egri is describing the underpinnings of procedural rhetoric.