Asteroid smashes into Antarctica!
Creates tidal waves. Sets off tectonic-plate and seismic activity. Essentially
changes the map of the world as we know it by . . . raising sea level
some 1000 feet.
Yep, we know that's not scientifically "reasonable"but it sure
is convenient for mapping!
Cataclysm Creates Magic!
Nope, we don't know exactly how or why. Theories abound, but now magic works
as per the GURPS system.
Cataclysm Creates Social Upheaval!
Big time social upheaval. The "Placia" continent (formerly known
as Appalacia) and many other places on the globe revert to "warlord"
governments in response to the chaos resulting from too many people, too little
food, and most of the infrastructure of civilization pretty much destroyed. (Coastal
cities got drowned, yes?)
For the most part, these governments become dukedoms that favor magic over
gunpowder. Towns pretty much rule themselves in quasi-democratic fashion "under"
the local Duke.
Home baseOur Faire City
Our characters live in Our Faire City (named for the splendid fairs it puts
on in spring, summer and fall), which is located roughly where Pittsburgh used
Adventures originate in Our Faire City, but whether we stay there, travel to
other towns on this or other continents, or travel to other dimensions, even other
pocket universes, is entirely up to the (rotating) GM.
A Few Other Places We Know About
The Techlands: Across the Missippi Sea, from Omaha westward into
the Rockies. Here civilization was least impacted. These folks favor technology
over magic (though have chosen to stay at a modest level of technology).
Texicana: South of the Techlands.
Treal: A French-speaking duchy north of the Missippi Sea.
The Orclands: Wild spaces abound on the planet.