There is no one common pattern - every plot is slightly different, otherwise people would stop reading new stories because they were all the same! The most common way to describe a plot is Freytag's Pyramid: Exposition > Rising Action > Climax > Falling Action > Resolution
Foster-Harris, in The Basic Patterns of Plot (University of Oklahoma Press, 1959) suggests there are three basic plot patterns
- "'Type A, happy ending'"; Foster-Harris argues that the "Type A" pattern results when the central character (which he calls the "I-nitial" character) makes a sacrifice (a decision that seems logically "wrong") for the sake of another.
- "'Type B, unhappy ending'"; this pattern follows when the "I-nitial" character does what seems logically "right" and thus fails to make the needed sacrifice.
- "'Type C,' the literary plot, in which, no matter whether we start from the happy or the unhappy fork, proceeding backwards we arrive inevitably at the question, where we stop to wail." This pattern requires more explanation (Foster-Harris devotes a chapter to the literary plot.) In short, the "literary plot" is one that does not hinge upon decision, but fate; in it, the critical event takes place at the beginning of the story rather than the end. What follows from that event is inevitable, often tragedy. (This in fact coincides with the classical Greek notion of tragedy, which is that such events are fated and inexorable.)
There are also those who have suggested 5, 7, even 20 "Master Plots" - see the link below for even more information.
