We have described a story as a battle. The overview that takes in the full scope of the battle is the Objective Story Throughline.
Within the fray is one special soldier through whom we experience the battle first-hand. How he fares is the Main Character Throughline.
The Main Character is confronted by another soldier, blocking the path. Is he friend or foe? Either way, he is an obstacle, and the exploration of his impact on the Main Character is the Obstacle Character Throughline.
The Main and Obstacle Characters engage in a skirmish. Main says, “Get out of my way!”, and Obstacle says, “Change course!” In the end, the steadfast resolution of one will force the other to change. The growth of this interchange constitutes the Subjective Story Throughline.
Taken together, the four throughlines comprise the author’s argument to the audience. They answer the questions: What does it feel like to have this kind of problem? What’s the other side of the issue? Which perspective is the most appropriate for dealing with that problem? What do things look like in the “big picture?”
Only through the development of these four simultaneous throughlines can the Story Mind truly reflect our own minds, pitting reason against emotion and immediate advantage against experience in the hope of resolving a problem in the most beneficial manner.
From the Dramatica Theory Book