Within the sphere of the Know World is another world, the Hollow World. There your characters will meet ancient Nithians, long disappeared from the surface world and thought extinct: Blacklore Elves, living in a magical valley and served by automatons-devices that take care of everything, from serving their food to trimming their grass: Azcans, terrifying, war-mongering natives whose taste for battle extends even into their favorite game-the loosers always die- and many more. Monsters abound as well, from dinosaurs to aurochs. "
I love abusing The Hollow World box set by Aaron Allston, Karen S. Boomgarden, & Bruce Heard. It is such a fun setting to drop PC's into & best of all its adaptable to both Advanced Dungeons & Dragons as well as BECMI Dungeons & Dragons . But can this wonderful setting be attached & used for other old school & OSR D&D style settings.
Different caverns & tunnels of the Hollow World have planar gateways into other D&D settings even though many of these are monitored & very dangerous. There's also the 'spell of preservation' issues along lots of other weird bits & pieces. Plus one has to deal with the Council of Intrusion ( the council is a party of immortals whose job is to eject any demons, devils, aliens, or cosmic entities from Mystara) if you were going to do a large scale otherworldly invasions you might be in trouble. But smaller parties,lone travelers, adventurers, etc. are not even going to be noticed. This got me thinking about Trey Causey's Dreams From the Sorcerer's Skull blog post 'Atomic Age riff on Operation Unfathomable'. What happens when some modern day adventurers blunder into 'The Hollow World' from a Fifties Atomic Age Operation Unfathomable? The Immortals are not going to bat an eye for one.
illustration by Nik Poliwko
The spell of preservation is going to cause all kinds of havoc with said adventurers. But let's take this further shall we.. If the door swings both ways then, what happens when Hollow World adventurers are exposed to the wilds of such a setting? Jason Sholtis's setting already has a science fantasy flavor about it & the Blacklore Elves might not be that shocked. But the races from the Hollow World? Well that's another matter entirely. The Azcans who make it back to their lands inside the Hollow World after experiencing Sholtis's science fantasy fueled nightmare vision will prepare for war!
Let's not even mention the Nithians or the Milenians both of whom have experience with the entire spectrum of occult techo science fantasy magicks & artifacts. What's really gonna be shocking is the array of inhuman & other worldly entities that rule the Operation Unfathomable setting itself. But let's take the planar gate way bit even further & use Astonishing Swordsmen & Sorcerers of Hyperborea. The Hollow World lines up with Underborea & we have several serpent men scientists or ophidian adventurers visit. This isn't going to be a major issue as the serpent men already have a foot hold within Mystara. Well that's not a problem because of the Vaults of Pandius B4 Lost City Sourcebook. Adventurers from Hyperborea are going to feel right at home with the prehistoric beasts & lost nations of The Hollow World.
The kings & queens of Hyperborea would see the Hollow World as an incredible resource to be exploited & also a possible location for trade. Maybe conquest but I doubt it because of the military resources of the Nithians or the Milenians could be a nightmare to deal with. But I can also see the setting being a perfect opportunity for some brave & very foolhardy adventurers from Lamentations of the Flame Princess stumbling right into the Hollow World & then dying. This is especially true of England Upturn’d campaign adventure By Barry Blatt & its use of the English civil war. This is very desperate England & a party of adventurers could make some dangerously inane diplomatic decisions.
By the same token but a completely different side of the coin an adventuring party from Albion from Lion & Dragon might have a very different experience. They've got experience with many kingdoms & lost lands. Albion is going to play it very cagey & learn as much as they can about the lands, religions, cultures, etc. before they set up trade or commit to a military objective. Albion is in the grip of its own civil war & can ill afford to deal with a planar war.
Finally there's the fact that with the Amazing Adventures fifth edition book winding down in less then forty hours I'd be remiss to mention that the Hollow World could easily be plugged into Jason Vey's baby. The Hollow World has a lot to offer AA! & could open up an entire can of worms for adventurers. I don't want to think of the ramifications of this meeting because its beyond the scope of this blog. But with the kickstarter winding down this classic setting seems primed for another look by AA! Rpg fans.
Moving back into the Hollow World for a moment the