26 lettered Earths, 1/x
Aerth - fantasy historical Earth: the fun parts. pre-gunpowder (it doesn't work) but other than that all your favorite historical eras squished up against one another. Earth-Xena, if you will.
Bearth - Earth but populated by evolved bears and other ursines
26 lettered Earths, 2/x
Cearth - Celtic catgirl/catboy earth. the sidhe and unsidhe clowders alternate being "ruled over" by Tom Tildrum or Tim Toldrum. see also, the Taìn.
Dearth - not a lot here, kinda miserable and gloomy, scarcity reigns except for gunpowder, gasoline, and greed
26 lettered Earths, 3/x
Earth - our Earth. most portals or other means of transit are laden with "enter at own risk"-type signifiers
Fearth - horror Earth. gloomy and foreboding. all the little horror subgenres of the past two-odd centuries get their little Ravenloft-style demesnes
26 lettered Earths, 4/x
Gearth - clockwork, steampunk, Victorians, extremely tiresome except for the modrons! i love those little guys
Hearth - halflings came from here, it's pretty cozy
Iearth - crystals, psionics, high magicks, home of the IOUN stones
26 lettered Earths, 5/x
Jearth - something about the light casts everything in shades of blue
Kearth - possibly Korean Earth, a never-divided Korean Empire as a major world power and cultural force.
26 lettered Earths, 7/x
Oerth - home of the Flanaess, the Circle of Eight, Vecna, the City of Greyhawk, etc. sports a deceptively stuffy and tedious surface over an amoral and murderous core. Oerth wasn't placed at the center of creation as its denizens claim, but they *are* awfully close to it.
26 lettered Earths, 8/x
Pearth - an odd, bottom-heavy planet, sparse population concentrated largely in the southern hemisphere, a strongly independent people who speak a deeply drifted dialect. everything also has a real juicy donk for some reason.
Quearth - gay, gay, gay
26 lettered Earths, 9/x
Rearth - Re-Earth. we started the whole thing over to observe it from the beginning, it's a thousand years behind and everything's gone totally off the rails, no supernatural shit but alternate history breakpoints ahoy
Searth - Sea Earth. more Momoa than Costner
26 lettered Earths, 10/x
Tearth - soap opera earth, everyone's angry or crying for some reason
Uearth - reverse map Earth. the lands are oceans, and all the sea is dry, dry land.
Vearth - Vampire Earth? some iteration of the World of Darkness, maybe Monte Cook's WoD, that doesn't get enough love
26 lettered Earths, 11/x
Wearth - it's eternally 1979 in the dreary aftermath of the Studio THX-1138-4B plastic junkie disco-slash-electric cocaine labyrinth, everything's run down and they can't keep the lights on. the calendar year resets on January 1st, everybody knows, nobody cares
26 lettered earths, 12/x
Xearth - fuck it, it's Gamma World, a superhero civil war blew everything up and now it's Gamma World
Yearth - it's the golden age of science fiction, all the major problems are solved and it's always 1965, the calendar year resets on January 1st and nobody seems to notice