Earth-20 is one of the many universes within the DC Multiverse. A pulp inspired world which is just recently leaving a great and devasting war behind and headed to an new phase of rebuilding and discovery. Depiste being chronologically in the same current year than earth-0, the technological development in earth-20 is more similar to the early 40's. Radio-cinema (television) is just a recent invention in that world. But while Earth-20 may be entering a period of enlightenment, danger still exists, inspiring a rollicking crew of extraordinary individuals to rise up and unite in defense of their planet—the Society of Super-Heroes!
With a global population of only 2.327.748 human lives, new adventurers (science champions) had rise against the hiden dangers of the world: Doc Fate, Immortal Man, the Mighty Atom, Green Lantern Abin Sur and Lady Blackhawk (leader of the ferocious female aerial squadron that bears her name) travel the face of the globe, protecting their fellow people from threats both powerful and strange.
Adventurers and science heroes all, the men and women of the S.O.S. represent the very best that their Earth has to offer, providing a formidable challenge to those who would seek to do harm to their home.
Sadly, Earth-20 occupies a binary universe than every 100.000 years tuned itself with earth-40, its evil counterpart. The last tunning was catastrophic for earth-20 inhabitants who had to endure a extradimensional invasion lead by the Society of Super-villians, instigated by the Gentry. Tricked into cause their own destruction the heroes of earth-20 however survived the invasion and stopped the forces of earth-40 but at highly costs.
The circunstances of their battle are unknown but positive. After the end of their home world crisis, one inhabitant of earth-20, Green Lantern Abin Sur, joined the volunteer multiversal army, Justice Incarnate.