Point of divergence

In discussion of counterfactual history, a point of divergence (POD) is a historical event, with two possible postulated outcomes. Typically these represent the actual course of historical events (Napoleon lost the Battle of Waterloo) and another, such as Napoleon won the Battle of Waterloo.

In alternative history fiction, the POD is used as the starting point for the extrapolation. A new post-POD world is discussed, based for example on Hitler winning World War Two.

The multiverse theory posits that PODs are occurring all the time, with an infinite variety of possible outcomes that each creates a universe.