Alternative versions of Superman establish a new continuity for DC, affecting not only Superman, but all of the DC Comics characters. The versions of Superman from this time period are traditionally divided into three main periods. The first version of Superman began being published by DC Comics in 1938 appearing in "Action Comics" #1. To explain discrepancies in the aging of Superman across several decades, his earliest stories were retroactively portrayed as having taken place on an alternative world called Earth-Two. These stories take place from 1938 until the late 1950s, although the exact dividing line is unclear and some stories happened identically to
Superman Red/Superman Blue Superman Red/Superman Blue Superman Red/Superman Blue refers to two different comic book storylines published by DC Comics featuring Superman. The original Superman-Red/Superman-Blue tale is an "Imaginary Story" that first appeared in "Superman" #162 (July 1963). The script was written by Leo Dorfman, with art by Curt Swan. In the story, Superman is compelled to finish a list of unaccomplished goals, including the enlargement of the Bottle City of Kandor and eliminating crime and evil from Earth. In order to accomplish these goals, Superman invents a machine, powered by various types of kryptonite, that will increase his intelligence. The machine works,