Brave New World
My brain cross-patched in the idea of a mind flayer nation one of my players wanted to fight (yes, he made the suggestion) and the githyanki another one of my players wanted to encounter. The final idea that came out was the Overdark.
The Overdark consists of sky islands made of the four elements and topped with tropical foliage and riddled with tunnels a.k.a. the Underdark. Portals connect island to island and gateways connect islands to other planes. The Overdark's name means two things. One, it refers to the tunnels inside the islands. Two, the islands cast shadows on the ground below creating darkness from above, i.e. the Overdark.
The PCs are currently adventuring through the module the Red Hand of Doom. I figure they'll be 10-12th level when they finish, so I'm going to design this new portion of the world of Terra with these levels in mind. When they finish that quest, they can start exploring the Overdark.
For this column, I'm going to build the Overdark from the ground up. I'll be sending my PCs through the Overdark, but maybe other GMs two will get some ideas here they can use as well.
Setting: Islands
I decided on mostly small islands, probably none bigger than a city. One problem I have with the Underdark is it big. Too big. Like one big dungeon. D&D 3.5 doesn't handle big dungeons to my satisfaction. I like the approach used by the designers of the Red Hand of Doom. Lots of smaller dungeons each with a unique look and theme.
Beyond that, I see the islands being built of the four elements and held aloft by natural buoyancy, much like a beholder. Dispel magic won't send one crashing to the ground.
Setting: City of Glass, Plane of Elemental Water
The City of Glass is described in Manual of the Planes. It is a large planar city filled with both air and water. Direct connections to this city and the floating islands of Terra exist.
I've always liked the City of Glass of the various planar cities described for D&D so far (Sigil, City of Brass, etc.). The combination of water and air makes for a challenging setting and the creatures encountered can vary from marids to mind flayers.
Setting: The Underdark
The Underdark does exist and a few portals connect it to the Overdark. It is a truly inhospitable and alien place. I'm saving some of my most difficult adventure and dangerous monsters for the Underdark.
The drow actually live on the surface in a nation of their own. Nothing about the Underdark, even the tunnels and caves, will be completely familiar once the PCs get around to exploring it.
Setting: Monsters
Monsters I have in mind include the mind flayers and githyanki as major players. The dao, efreeti, and githzeri have minor holdings. And the races from the Planar Handbook have a few outposts. Races of Terra are rare in the Overdark. Of course, flying creatures of all types make their home in the Overdark and a surprising number of burrowing creatures as well.
The islands of the Overdark are an alien environment. The presence of the mind flayers has changed the setting to make it more comfortable for amphibian-like, brain eating aberrations. The PCs should feel more and more uncomfortable the closer they get to a mind flayer outpost.
Player Characters
Player characters have to be tough to explore the Overdark. If I started a new campaign there, I'd have PCs start at 10th level. I'd recommend the races from the Planar Handbook along with the githzeri as being the most common PC races.
Campaign
In my Darkness Falls campaign, I'm going to tie the mind flayers of the Overdark to the introduction of half-bloods (half-aberrations) to the world by slavers. While the half-bloods work to undermine the temple of Solarus the sun god from within, the mind flayers work tirelessly to destroy the sun itself from the Overdark.
In addition, the githyanki will have a role both on the material world of Terra and in the astral plane. I'm still working out the details, but I want to have a few surprises ready for the players.
Next Month
I'm going to start putting together some adventures in the Overdark.
