Exploiting The Hollow World Setting & OSR Games

"THE KNOWN WORLD: IT ISN'T FLAT, BUT IT IS HOLLOW. 

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 

HWA1 Nightwail (Basic) adventure could be used to rope in otherworldly adventurers into the setting. Because its a relatively mundane adventure. NWA1 could be adapted for any of these settings & systems. 

Deeper Cuts into DDA2: "Legions of Thyatis" (1990), by John Nephew,

"REVOLT OF THE GLADIATORS!

The corrupt Thyatian senator, Helenites Osteropolus, his latest scheme smashed by the adventurers and their gladiator allies, hatches a new plot to destroy the influence of the Order of the Sands (even, perhaps, to attack the Emperor himself!). Yet greater dangers lie ahead. If his plot succeeds, it will remove the guardians that protect the city from the creatures that lurk in the caverns and catacombs below. Can the players block his gambit? Will the wheels of justice grind small, or will the greasy palm of political corruption reach out and save the senator once again? YOU decide, in the chaotic swirl of the Thyatian capital's politics."
DDA2: "Legions of Thyatis" (1990), by John Nephew, is an adventure for the Basic D&D game. It was published in August 1990. Taken as a whole this is a module that's like a ticking time bomb with a campaign coupled with DDA1: "Arena of Thyatis" (1990), by John Nephew. These  two books should have been one product in my humble opinion.
But back to the blog entry because what DDA2: "Legions of Thyatis" (1990) represents is a mini campaign waiting to happen. I've used this series of modules with Greyhawk, Dark Sun, Astonshing Swordsmen & Sorcerers of Hyperborea, and many more. But for the moment let's concentrate on Mystara.



"The player's PC's have to venture into a labyrinth of catacombs to prevent the senator from eliminating the wards that protect Thyatis City from the monsters in the subterranean realm beneath it." And this is where things get very interesting because DDA2: "Legions of Thyatis" (1990) catches, codifies, & twists the expectations of the setting of The Empire of Thyatis like a rag doll. There are monsters below the empire & all of this ties directly into the history of the empire. According to the Thyatis wiki entry;

"Karameikos is ruled by a Thyatian nobility, but the Empire's territories consist of the western half of the Isle of Dawn, the island realms of Ochalea and the Pearl Islands, and the Thyatian Hinterlands on the southern continent of Davania, in addition to its mainland territories on Brun, which are the smallest of the Empire's territories by geographic size, but the most heavily populated and developed of them. The total land area of the Empire is approximately 800,000 square miles (2,100,000 km²). Because of its political geography, Thyatis can best be described as a thalassocracy.

In its long history, Thyatis has ruled other lands, including Traladara (which became Karameikos), the islands of Ierendi, the southern half of Ylaruam, and the city of Oceansend in Norwold. Thyatian settlers have colonized part of the Savage Coast and also the Heldannic Freeholds, which are ruled by a religious order devoted to the Thyatian-descended Immortal Vanya.

Thyatis has a historic rivalry with the Alphatian Empire, and the two imperial powers devote much of their energy and attention to each other. At the start of the official timeline (AC 1000, or thousand years after the crowning of the first Emperor of Thyatis, in the Thyatian calendar), they are locked in a struggle resembling that of the Cold War, and several published high-level modules have their territorial disputes as a backdrop (notably CM 1, M1, M2, and M5)." This struggle ties directly into the material of the Hollow World itself.


So what happens if the events Wraith of the Immortals box set  never happened?! Well the Wiki entry hints at that much & possibly more saying; "The adventures of the boxed set Wrath of the Immortals takes place within the context of a great war between the two, climaxing in the weakening of Thyatis and the sinking of the continent of Alphatia. Subsequently, Thyatis conquered a few formerly Alphatian territories, suffered setbacks and plague, and by the final official publication that made much mention of Thyatis (Joshuan's Almanac) seemed to be on the road for a gradual recovery. Many campaigns did not use Wrath of the Immortals and the development of their versions of Mystaran countries, particularly Thyatis and Alphatia, may have diverged greatly. In particular those who used earlier published modules, such as CM1 Test of the Warlords or M5 Talons of Night, which involved different conflicts and possible resolutions, could have ended up with very different versions of the Empires than what occurred in the Wrath timeline.

In a review of the adventures Arena of Thyatis and Legions of Thyatis, game designer Ken Rolston called Thyatis "a D&D-game version of ancient Rome", and the city of Thyatis itself an "ancient Roman city", saying: "You have your basic criminal syndicates, debauched and corrupt senators, sinister intrigues, big parties, and lots of hearty Spartacus-style gladiators.""
All of this is wrapped up with a spectacular issue of Threshold magazine #11v2 that addresses this & several other issues tied in with the altering of the Mystara timeline 

The real issue is the strong adventure connections between Arena of Thyatis and Legions of Thyatis, with 'The Milenian Empire' of the Hollow World. What if the same basic criminal syndicates, debauched and corrupt senator's network extends down into the Milenian Empire. Could it actually be that the Merry pirates are working with the this corrupt network & thieves guild in disguise?! Think I'm kidding?! Think again.


In History of the Thyatian People by James Ruhland the secrets are laid bare for all to see. The corruption & horror of the gladiatorial game of the Thyatian people is laid bare. The Merry Pirates line their pockets with the gold of the Milenian Empire while new gladiators are brought into the capital. While above on the surface a minor gladiator revolt revolves around the empire of Thyatis? No this isn't going to end trade at all because the pirates are part of the smugglers of Mystara. That tight network has been ferrying goods, contraband, slaves, etc. for centuries.
What does any of this have to do with Mentzer edition BECMI Dungeons & Dragons? Everything because the Expert set's rules build on wilderness & sea adventures. This raises the stakes a bit if the PC's are going to carry the fight & revolt into and about the Thyatian empire.


Taken as a whole these two modules make an excellent start to a mini campaign that can lead to epic campaign lead ins.  Arena of Thyatis and Legions of Thyatis, are classic BECMI Dungeons & Dragons adventures that expose the dirty underside of the Thyatis empire & remain a favorite of mine. 

Taking a Deeper Slice of DDA1: "Arena of Thyatis" (1990), by John Nephew

"And simply everyone is going to the magnificent Villa Osteroplus, home of the wealthy old senator, Helenites. Raucous fun, exotic food, and even advanced betting on the upcoming Arena games are expected. Even adventurers just in from the outlands may meet the powerful here. So don your festive togas, for in Thyatis City there are important connections to be made and deeds to be done, duels to be fought and fame to be won. 

This module is designed especially for the DM who want to sharpen his interactive skills."
DDA1: "Arena of Thyatis" (1990), by John Nephew is one of those modules that puts the PC's at the far end of Thayatis. For Mystara Thyatis a major player think late & early Roman empire with lots of decadence & dark issues. There is a solid Wiki entry that fills in some of the gaps; "Thyatis (the city) is the capital of the Empire and the largest city on Mystara. It is on the southeastern coast of the continent of Brun, situated between the trade lanes of the Sea of Dread to the south and the Sea of Dawn to the east, alongside a canal ("Vanya's Girdle").

Conceptually, Thyatis is a mixture of different parts of the various historical Roman empires. It is governed by an Emperor and an Imperial Senate as per the classical Roman Empire, but enfranchises a feudal noble class similar to that of the Holy Roman Empire. The Emperor himself is akin to that of the Byzantines (as is the capital city's placement on a major strait). The Imperial Bureaucracy as described in Dawn of the Emperors is clearly inspired by that of the British Empire, as is, at least in name, one branch of the Thyatian Armed Forces, the "Retebius Air Corps" (RAF), which consists of cavalry on flying mounts (Pegasi, Hippogriffs, Griffons, Sphinxs, Rocs, and Dragons).

Karameikos is ruled by a Thyatian nobility, but the Empire's territories consist of the western half of the Isle of Dawn, the island realms of Ochalea and the Pearl Islands, and the Thyatian Hinterlands on the southern continent of Davania, in addition to its mainland territories on Brun, which are the smallest of the Empire's territories by geographic size, but the most heavily populated and developed of them. The total land area of the Empire is approximately 800,000 square miles (2,100,000 km²). Because of its political geography, Thyatis can best be described as a thalassocracy."

What this module does is puts the PC's center stage into the role of gladiators & not unlike Conan they begin to deal with the ranks of that & "Arena of Thyatis" is strongly  tied to Dawn of the Emperors: Thyatis and Alphatia (1989),



This module isn't going to put the PC's center stage instead its going to put the PC's on the edges of the empire with the themes of  "political corruption &  drug abuse taking center stage." There is a Spartacus feel to the adventure. Survival is dependant on being clever & cagey in the backdrop of this corner of the empire. Yesterday's blog post put the PC's square in the middle of the Mystara urban kingdoms. But what happens if you want to bring the action on the outskirts of civilization? The PC's are going to have to navigate NPC's, opportunities, & a refinement of the rake class. Indeed many of the advantages of DDA1: "Arena of Thyatis" (1990), is that it takes full advantage of Mentzer's Dungeons & Dragons Basic. 


 Helenites Osteropolus, a Thyatian senator, is the pig that makes makes life for the PC's utter Hell. DDA1 is worth the price of admission because of the extensive details on the gladiators of Thyatis. They can play an important role in the PC's lives in the days of the campaign yet to come. DDA1: "Arena of Thyatis" (1990) is one of the key modules for Mystara's Hollow World. The ancient caverns beneath the collusium directly tie into the Hollow World itself. In fact in recent years I've had these tunnel systems & ancient lava tubes connect with 'The Milenian Empire' book's setting  by  Anthony Herring from 1992. This gives the material a nice sly but contemporary connection between these two very different empires with common ground.


The NPC's of DDA1: "Arena of Thyatis" (1990) are well thought out & clever to cause the NPC's trouble. This is literally their reason for being & keeping an eye or two on the issues plaguing the PC's is a fantastic idea. 

Hoplite & War Machine - 'The D&D Master Rules Set' (1985), by Frank Mentzer & 'The Milenian Empire' By Anthony Herring

"At last, the cycle is complete. Players and Dungeon Masters alike may experience the wonder of reaching for the ultimate levels of mortal might with the D&D Master Set. 

In the Basic Set you learned to crawl through dungeons and defeat the minions of evil. In the Expert Set you set out on wanderings through the wilderness. In the Companion Set you climbed to the pinnacle of success and founded kingdoms, conquered wild lands, and battled barbarian hordes. Now, in the Master Set, you can soar across the sky and into the pages of legend. 

These books are written for the experienced D&D player. The Master Player's Book expands on the known abilities of characters with new skills and spells. The Dungeon Masters Book features three sections that have become a standard for each rules set: New Procedures, Monsters, and Magical Treasures, all designed with the Master Level characters in mind. 

Now, you are only limited by your imagination. Answer the clarion call to adventure; the lands of legend await!"

Today I'm gonna talk about two books that don't seem to go together at all but fit together like hand & glove. "The D&D Master Rules Set (1985), by Frank Mentzer, is the fourth volume in Mentzer's BECMI rules series. It was published in June 1985", for most folks that's about the extent of this box set. A shrug & a 'meh' then they move on but that's a mistake. The  D&D Master Rules Set (1985), is like the cherry on top. This is the rules set that puts the other side of the battle rules into the war machine system. There's also expanded classes, spell, and weapons to the ultimate levels of mortal D&D characters. Seems fairly straight forward right?  The Millenian Empire of the Hollow World benefits quite a great deal by adding in 'The D&D Master Rules Set' to these Hollow World conquerors.  Yes I said conquerors! "Once a great people in the Known World, the Milenians now administer a mighty Empire in the Hollow World. Loosely inspired by classical Greece, this is a nation of philosophers, oracles, architects, and mighty pikemen in a strange land where Citizens elect their own leaders, and ultimately the Emperor himself.
A society as political as Milenia cannot avoid intrigue, and the land is rife with conspiracies. From the would-be Kings to the lowly slaves, to the dark, grasping servants of chaos. It seems everyone in Milenia belongs to one secret society or another.
But even on the surface, there's plenty of drama: from the legendary Acropolis to the eccentric Academy of the Arcane Corisa, adventure calls you to the Milenian Empire!"



Well if we take 'The Master Rules' set & add it onto 'The Milenian Empire' book by  Anthony Herring from 1992. Then we get a very dangerous empire indeed instead of a stagnate one that seems destined for the scrap pile of inner Mystara history. The military evolutionary stands of 'The Master Rules' expands upon the military options available for 'The Milenian Empire'. Oh indeed I can already hear the 'hurruf' from the old school traditionalist Mystara players.
There's damn good reason why the empire is going to need the sort of help that Frank Mentzer's offering in 'The D&D Master Rules. The empire is surrounded on all sides by enemies & the second the events of 'Immortals Fury' goes down that's going to prime opportunity for military action to begin.

Neither the 'Sons of Azca (HWR1)' nor 'Kingdom of Nithia (HWR2)'  are going to sit on their collective rears. There's going to be a huge land grab & militarily that is going to really shake up the Hollow World. Then there's the fact that many of the immortals of Mystara are gonna be dead. 'The Milenian Empire' has a number of high ranking generals, warriors, etc. who are gonna be fit to take up the quest of immortality that is offered in "The D&D Master Rules Set (1985), by Frank Mentzer. This might well be a back door into Mystara immortality if the DM sees fit.


So why would I be pushing for a more military option for all three of these kingdoms?! Because the one group of cut throats that folks seem to forget could become a very dominate power in the Hollow World. The Merry Pirates who are made up of a quilted pattern of the collected scum of many of the races of the Hollow World & Mystara. Their itching to let loose on these empires to sack them. If your thinking that there isn't a Greyhawk connection here well you'll be very mistaken. The Merry Pirates have ties to The Lordship of the Isles . Their craft quietly slipping between the cracks of the planes shifting over to Greyhawk for a handy resupply & to sell ill gotten goods. Only to have them slip back into the Hollow World. What's one ship or even a fleet to the Council of Intrusion? 

The merry pirates are the barbarians at the gate of the Hollow World. Their fleets represent some of the more advanced peoples of the 'Hollow World' & their waiting with their knives at the throats of the major empires. These empire's scum, prisoners, etc. all have swelled the ranks of the 'Merry Pirates' over the years.

Attack by Pirates By Artist Arnold Böcklin
"The D&D Master Rules Set (1985), by Frank Mentzer, is perfectly suited to show the spoils of war, violence of battle, the cost of blood shed, & futility of the siege in the Hollow World. There are spells, new artifacts, alternative paths to becoming an immortal, etc. many of which were reconned in the Immortals Box set.  But its nice to have those on the table to decide how & when you need your options as dungeon master for your players.