This is where you learn how to build your own campaign setting quick and easy.
Step One: Mapping the World
You probably know what a d20 is...so now you need a d20 global map layout. This is a polyhedron or d20 laid out flat as twenty triangles. The equatorial region is ten triangles (five pointed up and five pointed down) with five polar triangles pointing to the north pole attatched to the top of the equatorial band, and the same again attatched to the southern equatorial band. This is your blank 'Globe'.
Create a list of dominant geography and the chances it exists in your world and roll for each triangle:
1d20 Geography
01-10 Ocean/Sea
11 Desert/Desolation/Badlands
12 Mountains/Hills
13-15 Swamp/Fens/Bog
16 Plains/Grassland/Savanna
17-20 Forest/Jungle
Then draw in your ocean/land boundary map on your globe. Some land might connect across multiple triangles if they make contact at a common side (Europe and Asia) or are seperated by a narrow sea (Europe and Africa), or may link as a landbridge (Central America), or might be an isolated continent (Australia), or an archipelago of islands (south east asia).
These regions will be dominated by geography (red soil outback of australia) though at the smaller scale there will be valleys, forests, hills, swamps, lowlands, mountain ranges.
On an earth-sized world each of these triangles is four thousand miles per side of triangle.
Step Two: Map your Campaign Region
These giant triangles can be broken up into smaller triangles (2000 miles, 1000 miles, 500 miles, 250 miles, 125 miles).
At the local area map level you can scale your triangle per page of paper to a diamond made of two triangles 125 miles per side. So now you can build a map for your campaign. Its unlikely your PCs will live long enough to make it elsewhere...especially considering you are obliged to roll for encounters on a daily basis while they walk eight miles a day down a dirt road.
Here you have the greatwood, the mountains of doom, the kron hills, the free coast, and soforth.
Step Three: Map your Minerals
Minerals are significant to human History. Stone Tools gave us neolithic cultures, gold and copper gave us the first settlements to bronze age (with copper and tin), iron and coal gave us iron age and steel making. So by working out where (or were) your minerals and their concentrations are you can create a kind of history and a foundation on which your modern history is based.
So create a list of minerals and their chance of occuring for each region:
d20 Mineral
01-02 Tin
03 Gold
04 Copper
05 Coal
06-07 Iron
08-13 Silver
14-19 Salt
20 No more minerals
Basically you roll for minerals for the kron hills, mountains of doom, great wood, until you get a natural 20. Multiples of the same mineral indicate wealth or longevity of mineral type.
Minerals in our region:
Kron Hills: Coal (1), tin (1), Silver (4), salt (2);
Mountains of Doom: Silver (3);
Greatwood: Salt(5), silver (4), gold (2), iron (1);
Free Coast: Tin (1), Iron (1), coal (1), salt (10-they just kept coming), silver (3), gold (4).
Step Four: Begin building a Setting
Mountains of Doom: the mountains have good silver and the folk of the kron hills prefer its rich silver to the toxic silver of their own mines putting them in conflict with neolithic barbarians who live there. Some are Werebears.
kron hills: these folks have access to coal to smelt silver though the coal is in small reserves. They make silver arrow-heads and daggers, and organotin compounds can be as poisonous as cyanide. So the mines are unhealthy.
Greatwood: gold and silver mean these people make electrum death masks for their mummies. The white metal difficult to make using wood alone it is reserves for special use. They produce artefacts of silver, gold and electrum.
free coast: these people are involved in fishing, farming, salting foods as preservative, silver and gold are rich deposits though in the hands of a few lords, armed with iron then steel (iron and coal). Having no bronze age we might assume they migrated into this region putting them at odds with the indigenous Neolithic/post-Neolithic population.
As you can see we have some concepts for groups within the region:
People Mountains of Doom Kron Hills
History Neolithic Transitioning from Neolithic
Wealth Survival Silver
Technology Stone Tools Silver Weapons and coal smelting
Culture Survival of the Tribe Hunt lycanthropes
People Greatwood
History Stalled Transitioning from Neolithic
Wealth Electrum, gold, silver
Technology Crude Silver Weapons, Gold crowns,
Electrum Death masks.
Culture White electrum Death masks
They are 'wights' haunting the forest (Isolationist)
They hunt lycanthropes.
People Free Coast
History Migrated to the Region. Iron age people.
Wealth Electrum, gold, silver, iron (rare).
Technology Silver weapons are cheaper than iron weapons.
Iron smelting.
Culture Fishing with a salt economy.
Wealth in the hands of chiefs/petty lords.
To be continued...