Rocks Die, Everyone Falls is a short adventure (probably 3+ sessions) using the D&D 3.5e system, in which an experienced adventuring group takes on an assignment that doesn't go quite as planned. Here is some information about the setting.
You live and work in the Principality of Berramond, which is a political region governed by a Prince, under the general rulership of a King. The government is pretty laissez-faire, and doesn't interfere much in the lives of the people. This governing structure won't have much if any effect on your characters.
Berramond is bordered to the west by the Bexwin Sea. It's split nearly in two by the Hayden River, which runs from the northeast to the southwest, ending at Port Hayden. A major road runs alongside this river (called, imaginatively enough, Hayden Road). There are forests on both sides of this road/river.
Port Hayden is the major shipping port in this region, trading with other principalities (as yet unnamed!) in the kingdom.
To the west and north the forests are heavier, and there the Longwater Hills rise up to some major mountains. This region is more sparsely populated, and is best known for its mines.
To the east and south is a broad plain called the Redstone Reach, threaded by a number of rivers leading to smaller seaports. The southern area is a rich farming area, providing lots of crops and livestock to the kingdom. To the north it rises gently to some rolling hills, which is lovely land that incorporates lots of farming but also towns where the elite have country estates.
Not shown on the map: Feywild is something that exists.
This is a plane of existence one step removed from the Material Plane.
It is the natural home of fey creatures such as Satyrs and Dryads, but member of pretty much any other race of people or type of monster can also be found there.
Portals between the Material Plane and the Feywild are rare and limited. You've never personally been to the Feywild or known someone who has been, but you know of it.