What I'm doing differently from my regular homebrewed method, which consists of custom content interspersed with published material, is leaving space for megadungeons.
Boxed settings never interested me, but I have a fondness for modules. In this case I'm creating a customized background, while planning for large empty spaces in which I can fit things like Castle Whiterock, Rappan Athuk, Slumbering Tsar and the Greyhawk Ruins. No one lives long enough to complete all of these, but I like to leave it open. Just in case...
Worldbuilding with MegadungeonsIt shouldn't be a secret that I'm a big fan of Zak Smith's blog (and I totally agree with his gender politics, if you care), and through his copious links and posts I found this. As a mental exercise - well really I just like doodling maps - I used the short form of Bat in the Attic's sandbox campaign generation to flesh out the world using the campaign's starting point as the reference point.
Since the campaign had already begun with an introduction to Castle Whiterock, and my first round of players had introduced some juicy plot threads, I've been building on that. I've also taken a hybrid approach to creating the world map. No land-sat view for me! I'm kicking it old school!
Take a moment to read the link above about medieval mapping. What I like about these old maps is basically that they are WRONG. Even in a fantasy setting, with access to powerful divinations, flight, and so on it would be incredibly difficult to create the kind of maps you typically find in boxed campaign settings.
You might have a vague idea of what's over the horizon, but always from the point of view of a single observer. Would your 8th level ranger or your 15th level wizard even be able to recognize a USGS map? Probably not. And why would they bother trying? They have dungeons to sack, lairs to defend, threats from the personal and local to the apocalyptic. And then there's that raid on Asmodeus' castle planned for next week. Who cares about meter-accurate mapping when there are XPs to be gained?
Using T-O maps and Zonal maps from the link above I fleshed out the world - or at least one half of a hemisphere - to a sufficient level of detail to start things off.
My goal? Create enough of a background to evoke the players' imagination. Making a Knowledge: Geography check shouldn't regurgitate an encyclopedia page about the region (that's a sort of printed wikipedia for you kids). It may tell you where it is, generally, and general information about it with varying degrees of accuracy depending on how well you roll.
My campaign map runs roughly from west to east, with the current party's location - Merain - roughly to the right of center. The major geographical zones are presented in this order.
TarabiFar Tarabi. The mystic West. It is so old that its origins have been forgotten.
It is so vast that no one knows its bounds.
It is a place of slow, stately stagnation, where a traditional caste system dictates all.
The culture is so vast and sprawlingly complex that no non-native can comprehend it.
The worship of reptiles is common.
Cities are vast, strangely temple-like structures, ruled by exceedingly powerful individuals or conclaves. Some are even human.
Great for reptilian or jungle adventures of any kind.
The Lum ArchipelagoNot a nation, but a long island chain stretching hundreds of miles across the sea roughly from southern Tarabi to western Merain.
Treacherous to travelers, who perforce cross the straits and channels by ship.
Pirates, cannibals, slavers, feral merchant ports, tribes of all species, volcanoes, sea monsters.
Anything goes, including you!
Suitable for standalone/island based adventures, or the Slave Lord modules (AD&D)
MerainA kingdom in decline. In its heyday, it was crossed by two great road systems, the King's Road which ran from the northern capital to the furthest southern reaches bordering Ettur, and the Gold road which runs from the western port city of Galaron to the town of Eastgate bordering the dwarven realm of Skrod.
The current site of the campaign, where some exploration of Castle Whiterock has already begun.
SkrodThe great mountain range of this continent, the dwarven clans and their High King rule this forbidding realm.
At least they say they do. And only near or under the surface.
Really though, the dwarven realms are small, it's surface roads poorly maintained and patrolled.
These ancient mountains have cracked open in places, revealing mysteries within their strat harkening back to primeval times.
Deep Carbon Observatory, Expedition to the Barrier Peaks, Greyhawk Ruins, Anything Underdark related.
KohanA sprawling, decadent coalition of free city-states spreading across the dry plains, rocky hills and fetid moors for a thousand leagues.
Patient, insular, convoluted, subtle.
A demon-haunted realm.
Rappan Athuk, Slumbering Tsar.