In the intro to 20 Master Plots: And How to Build Them, Ronald Tobias addresses the question of how many archetypal stories exist, citing answers ranging from 2 to 69. I like his list of 10 action-driven and 10 character-driven plots, each of which he breaks down into the essential beginning, middle, and ending events.

But while Tobias's book is meant to be a practical guide, it's also a reminder that we make fools of ourselves when we reach for absolute originality. In the words of a character I created for a play some 20 years ago, "Love stories are all the same, except for the words."