The campaign is set on an isolated peninsula created by a mostly dormant volcano and two huge fjords - think Norway or Iceland, except the water-side cliffs are incredibly high, steep, and with rocky coasts - no sea access. The land, called Oka Kjurama, was founded long ago, but almost three centuries ago, a curse fell upon the land as the thegn and most of his family died. This curse is almost like an overhanging doom (frequent poor crops, two-headed goat births, badly timed building collapses), but is most evidently personified in Kamidottr, a fearsome and eldritch troll that lives somewhere within The Great Twilit Bridge - a massive (almost a days walk to cross) stone bridge spanning one of the fjords, connecting Oka Kjurama to the mountainous Trollwalls and the tundra beyond - the only real access in and out of Oka Kjurama. The entire peninsula is now informally called the Trollfed Aerie, because it is effectively up to Kamidottr as to whether supplies come and go.
Despite Kamidottr's presence, Oka Kjurama hasn't completely succumbed to the curse yet; the various peoples that live within the Trollfed Aerie have just enough industry to get by, although they are in decline. Occasionally, a larger armed convoy has attempted to cross the Great Twilit Bridge to gather supplies from the mainland, and Kamidottr hasn't bothered them in any significant way, but smaller groups have been driven off or killed. Not that the larger convoys help much; the last one, several decades ago, came back with the devastating news that the Kangel orc hordes had laid waste to the lands beyond the Trollwalls. So the peoples of Oka Kjurama stay and live as best they can, taking what joy they can in small hopes.
The land is as cosmopolitan as such a small area can be (roughly 40 miles east-west, 20 miles north-south); all standard races are present in some number (which may only be 1 or 2 for some of the more exotic ones - ie, you can be any standard race, but you may be the only one left of your kind in the Trollfed Aerie). Culturally, the peoples of Oka Kjurama are a mix of Norse and Japanese traditions, although various races embody certain aspects more than others (for example, the dwarves enjoy sumo wrestling and great tales told within sake halls; the eldarin perform a complicated, mystical, and little understood, tea ceremony; the bodies of the dead, particularly thegns and other respected persons, are typically set afire on funeral boats and sent over the waterfall to plunge into the storm-tossed sea below). The main crop is rice (for food as well as sake), although goats are bred for meat and milk. The vast majority of buildings are single room longhouses, possibly with rice paper screens for privacy, in which multiple families may live. Players are more than welcome to expand on these cultural traditions, should they choose.
There are a few communities within the Trollfed Aerie - Kjuriyo is the main town, located at the western tip of the peninsula overlooking the Gods' Wrath Sea far below and focused around two main buildings - the great sake hall of Valhama and the Keep of the Last Sight, with the once-awe-inspiring Heavenhung Tower hanging precariously over the edge of the cliffs; Durel-dor-shima is an undergound mining village part-way up the (perhaps not quite) dormant volcano Kjur Peak that dominates the northern side of the peninsula that is the center of smithing and industry for the Trollfed Aerie; Kawasiddr is a nearly hidden forest village sheltered deep within the Aelfkami Woods to the south, and is more grown and spun from trees and silk than masonry and carpentry; and Fryjjarwa is a small village that sits on a series of islands in the river that runs through the middle of the peninsula and serves as the crossroads between the other three main communities and the Great Twilit Bridge to the east. There are several other thorps within the land, but none deserving of a name and few are more than a longhouse or two. Outside of these, the land is fairly dangerous - especially to non-adventurers: goblins inhabit vast caverns beneath Oka Kjurama, occasionally surfacing to raid; malicious fey and shadow spirits roam the Aelfkami Woods, preying on the weak-willed; and carnivorous drakes hunt along the slopes of Kjur Peak, picking off inattentive travelers.
All of the Player's Handbook gods exist, although their depictions might vary (ie, expect Norse and/or Japanese flavouring), but there are no real temples as such - instead, all worshipers are invited to silent prayer inside sacred gardens gated by brilliant vermilion torii and watched over by various mystical spirits known as kami. The four major communities each have such a garden, and a mostly abandoned one can be found near the Great Twilit Bridge in the east. Beyond the gardens, numerous shrines can be found dotted throughout Oka Kjurama, nearly anywhere a kami has taken residence or a touch of divine is felt.
The land is not excessively rich, and even the largest community, Kjuriyo, is barely classified as a town, but there is evidence of an even older peoples having lived on the peninsula long ago, so plenty of magic items can be found in the deeper wilds, caverns, and ancient ruins. Still, there is enough goods production that pretty much any sort of mundane equipment can be found somewhere.
The thegn Njall Strothtoshi, called Firebeard, has recently died, and his son, Hayazo Strothtoshi, called Njallssen, is the new thegn of Oka Kjurama, and is getting his father's funeral pyreboat ready.
Game Tone and Expectations
I like running games with a good mix of combat and non-combat encounters (exploration, puzzles, negotiations, etc), so expect such. From the setup, it is likely that confronting Kamidottr will be an eventual goal in the campaign, but not necessarily the ultimate one. There will be plenty of other bads (both big and little) trying to throw their weight around the Trollfed Aerie.
While there's very little in the way of "urban" environments, there will be some adventures/encounters based in the communities, and some based in the wilderness. There will be some dungeon crawls, but I'm hoping to keep them short - particularly in a PbP environment, I prefer my dungeons to have minimal "useless empty rooms", and I'm a big fan of reusing dungeons (ie, the party may very well have reasons to return to previously visited ones).
For those wondering about "loot", I like making custom items to sprinkle in with more "mundanely" rolled stuff. Names, backstories, unique functions. They may or may not have been playtested, and I reserve the right to change anything I hand out if I realize I made a mistake in their design.
While I'm certainly no scholar on Norse or Japanese mythologies, a lot of info I gleaned from Wikipedia on the subjects will be coloring the game. In particular, stuff like Nordic runes and Japanese kami will be all over the place - whether you notice them or not.