It is important to be clear about the difference between the Main Character and the Obstacle Character. The audience looks through the Main Character’s eyes, and through them looks at the Obstacle Character. Through the Main Character, we feel what it is like to be in a particular predicament. With the Obstacle Character we see an external view of what someone else looks like in the same predicament. Since we cannot really climb into and become this character, we can only judge him by how he affects the characters and events around him.
As an example, if a Main Character were physcially challenged, during the duration of the story the audience members would also feel physically challenged, suffering the problems this creates as if it were a problem in their own lives. If the Obstacle Character were physically challenged, the audience would examine the problem from the outside, learning more about the difficulties logistically, not experientially. The focus would be on how this physical challenge impacts others. “Impact” is the key word to keep in mind when examining the story’s problem in the Obstacle Character Domain.
From the Dramatica Theory Book