Hollow World
The Hollow World is a campaign sub-setting for the Dungeons & Dragons setting of Mystara, released under the Basic D&D mechanics system. The Hollow World, as its name implies, is a result of Mystara embracing a more pulp fantasy approach than the neo-Medieval approach of Greyhawk; it's a world that exists inside the hollowed-out center of the planet itself.
To expand on that... Mystara the planet doesn't merely have an Underdark, but it has an enormous hollow mass at the planet's center - picture the planet as a balloon made of rock and you've got the right idea. Aside from secret tunnels in the Underdark, it can only be reached through two huge portals at the northern and southern poles of the planet. Carefully develoed by Ka the Preserver and an alliance of other Immortals, the Hollow World serves as Mystara's preservation grounds; every species and culture that has ever died out on the surface is preserved here, in eternal stasis, from neanderthals and dinosaurs to Blackmoor elves with their robot servants to the primordial Kogolor, ancestors of dwarf and gnome.
| Dungeons & Dragons Campaign Settings | |
|---|---|
| Basic D&D | Mystara (Blackmoor) • Pelinore • Red Sonja |
| AD&D | Birthright • Council of Wyrms • Dark Sun • Diablo • Dragonlance • Forgotten Realms (Al-Qadim • The Horde • Icewind Dale • Kara-Tur • Malatra • Maztica) • Greyhawk • Jakandor • Mystara (Hollow World • Red Steel • Savage Coast) • Planescape • Ravenloft (Masque of the Red Death) • Spelljammer |
| 3rd/3.5 Edition | Blackmoor • Diablo • Dragonlance • Dragon Fist • Eberron • Forgotten Realms • Ghostwalk • Greyhawk (Sundered Empire) • Ravenloft (Masque of the Red Death) • Rokugan |
| 4th Edition | Blackmoor • Dark Sun • Eberron • Forgotten Realms • Nentir Vale |
| 5th Edition | Dragonlance • Eberron • Exandria • Forgotten Realms • Greyhawk • Ravenloft • Ravnica • Theros • Spelljammer • Strixhaven • Radiant Citadel |