Like other forms of Speculative Fiction, Alternate History varies in its inherent "hardness" with AH Fandom generally grading it by how "plausible" the AH is based on historical realism and verisimilitude. At the "hard" end of plausibility are well-researched pieces that take into account historical sources and trends, logical changes due to the Butterfly Effect, and try to produce allohistorical events that flow logically from the Point of Departure/Divergence (PoD). At the "soft" end are works of pure Fantasy and Rule of Cool, generally a result of Alien Space Bats. Examples :