In Dramatica narrative theory, there are some story points that deal individually with the structure and others that pertain to the collective impact of a number of story points. Audience Reach is one of these combined dramatics. It is also called an Audience Story Point because it is concerned with the kind of reach the story has into the audience.
Specifically, it describes whether your readers/audience will empathize or sympathize with your Main Character. Empathy is when your readers/audience identify with your Main Character. Sympathy is when they care about your main character but feel more as if they are standing right behind the character, rather than in its shoes.
When audience members empathize, they suspend their disbelief and emotionally occupy the Main Character's position in the story. When audience members sympathize, it seems to them as if the emotional maelstrom of the story revolves around the Main Character, making him or her the Central character of the story.
Audience Reach is determined by the effects of two story points: Story Limit and Main Character Mental Sex. Limit describes the story dynamics that force the story to a conclusion. Mental Sex describes whether your Main Character thinks like a man or a woman.
Story Limit has two variations - Time Lock and Option Lock. Time Lock stories are like the motion picture "48 Hours" in which a police detective has exactly two days before he has to return to jail a convict who is the key to solving another crime. When the time is up, the story reaches its conclusion.
Option Lock stories are similar to Disney's "Beauty and the Beast" in which a transformed prince must make someone love him before the last petal falls from an enchanted rose or he will remain a beast forever. When the last petal falls, the conclusion is reached.
Main Character Mental Sex also has two variations - Male and Female. Mental Sex does not refer to the physical gender of the Main Character but only to its mental gender. (Because none of us truly know how the opposite sex thinks, authors often can't help but write all of their characters as thinking in their own sex, regardless of the character's physical gender.)
Examples can be seen in the motion picture "Aliens" in which the Main Character (Ripley) was actually written for a man and changed only the character's dialog when the role was cast with Sigourney Weaver. Alternatively, in the movie "The Hunt for Red October", Jack Ryan is a female mental sex Main Character as he solves problems intuitively and emotionally, rather than by observation and logic.
As one might expect, male and female readers/audience members empathize or sympathize with a Main Character for different reasons.
For men, they will empathize with Male Mental Sex Main Characters and sympathize with Female Mental Sex Main Characters, regardless of which limit is invoked - time lock or option lock. Conversely, women will empathize in an option lock but only sympathize in a time lock, regardless of what mental sex the Main Character possesses.
Why the difference? Well, the reasons are in the physiology of the brain, and too deep to go into here. If you are really interested, you'll find a complete description of what causes the mental differences between mean and women later in this program in a lesson devoted specifically to mental sex.
Still, for a quick visual, imagine a plain old clock face. Imagine that men's minds sit at noon, and women at 9 o'clock. Thinking clockwise, men see women as being three quarters of an hour away. Women see men as only being one quarter of an hour away. This serves to illustrate that the sexes really aren't opposite, but are more accurately sideways to each other.
When men and women converse, they are often speaking apples and oranges and are not really in conflict or disagreement. They simply don't have a means of seeing things the way the other sex does. So, it is not surprising that men's empathies might be drawn to those who think like them (also at noon on the clock) while women (seeing men as just one quarter hour away) would be more affected by the situation in which the main character finds itself. For women, an option lock is more like the way they think - trying to balance all the elements at once, just as in their own lives. But time locks (to women) are just deadlines and seem imposed from the outside rather than open to some degree of control.
Okay, lets put that behind and see what we can do with this information.
If you want to create a story in which both men and women empathize with the Main Character, then you will want to limit your story with an option lock but employ a Male Mental Sex Main Character. On the other hand, if you want to explore a despicable Main Character, you may not want to disturb your readers/audience by making them empathize with such a cad. In such a case, you can ensure your readers/audience will only sympathize by writing a Female Mental Sex Main Character in a time-lock story. The danger is that since nobody empathizes, nobody really gets into the story and it doesn't sell very well.
Naturally, the other two combinations can also exist - Men Empathize (Male Mental Sex) and women Sympathize (Time Lock) or Women Empathize (Option Lock) and men only sympathize (Female Mental Sex).
You can predict whether a book or movie will attract more men or women, just by seeing who empathizes. Hollywood tends to favor Male Mental Sex / Option Lock stories most often. This has the entire audience empathizing, and therefore (since far more mixed mental sex couples go to movies that single individuals or same mental sex couples) it ensures the largest percentage of the audience is personally involved in the movie, thereby increasing its box office (all artistic merit aside).