From Ask Yahoo (5 March 2007):
There are only so many ways to construct a story.
Writers who believe there’s only one plot argue all stories “stem from conflict.” True enough, but we’re more inclined to back the theory you mention about seven plot lines.
According to the Internet Public Library, they are:
1. [wo]man vs. nature
2. [wo]man vs. man
3. [wo]man vs. the environment
4. [wo]man vs. machines/technology
5. [wo]man vs. the supernatural
6. [wo]man vs. self
7. [wo]man vs. god/religion
Ronald Tobias, author of “Twenty Basic Plots” believes the following make for good stories: quest, adventure, pursuit, rescue, escape, revenge, riddle, rivalry, underdog, temptation, metamorphosis, transformation, maturation, love, forbidden love, sacrifice, discovery, wretched excess, ascension, and decision.