Campaign Toybox
The Story: Your average fantasy setting has at least one, if not many species who dwell underground. Failing that, there are plenty of reasons why a society or splinter group of humans would choose to live underground. Now, your average large medieval city or palace might have hundreds of miles of sewers beneath it, and much more if it is built on a cave-riddled hillside. The underground doesn't have much - limited food (just rats and fungus), poor ventilation, constant darkness - but it has its own built in security. Upworld is the opposite: plenty of food, just lying around on stalls and tables, clean air, bright sun - but it is full of danger. Your enemies can see for miles, in clear straight lines, and your soot-stained rags make you stand out a mile in this world of cleanliness. There are guards everywhere, just waiting to send you back down your hole, or lock you up. But if you're clever, and you keep your visits short, you can eat well, taste adventure and if you take down a few of the bigger "creatures", you can come home with a king's ransom in coins.
In fact, a whole culture has arisen around these upraiders. It takes a very rare kind of person to risk going into the upworld - some would say, a very crazy kind of person. But nevertheless these people exist, and the bravest and the best come back with wild stories and strange treasures, and may just become the heroes of songs and legends.
Style and Structure: Any conceptual reversal is hard work. You don’t want your players to find it too easy to invert their thinking so that it ends up feeling exactly the same, but if you constantly filter everything through a mirror, it will become insufferably twee. Don’t go so far as to mess with fundamental concepts – even down in the dark there are such things as morning and night, and light and dark still mean the same thing. Likewise, just as most D&D players don’t want to have to track the life cycle of every torch they light, PCs here should have to check every round if they know not to look directly at the sun or to realise that the “strange quadruped” is a horse. It can be fun however to think of as many analogues as you can to D&D – instead of torches for the dark, perhaps the city-delvers need smoked-glass goggles to protect against the sun. Perhaps the dwarven ability to understand stonework can now become Street-Cunning, allowing its users to guess which streets are likely to lead where. Perhaps the stone-growing grey ooze is replaced by the sand-spore, the poison of which the surface folk are completely immune. Again, you need to resist silliness, but just existing in the overworld needs to be dangerous.
Plots are where you are most likely to run into the dread twee-ness – you should resist sending them to scout through mansions full of traps and locked doors to find a giant nobleman curled around his vault of cash! Start your plots from scratch, envisaging the enemies of the underworld, and what resources or clues to stopping them the overworld can provide. Don’t be afraid to do a few adventures below, too – it is vital that the overworld remain exotic as well as dangerous, and building up a sense of home in the underworld is a key part of that.
PCs and NPCs: The fun part of this is raiding your fantasy world’s toolbox. We’ve all killed goblins, kobolds and countless other types of sub-terranean; now you get to create a society for them, and from them, choose your PCs and NPCs. The NPCs can be based on the template of any fantasy village or town, with just a few simple adjustments to underground life (fungus farming, beetle livestock etc) or a monstrous population (change the gods in the temple, replace the annual barn dance with a warchant etc). You could even choose as a basis the very foes your most recent PCs fought or vanquished, or, later, send more traditional PCs into fight their previous identities. Although you may think players wouldn’t want to kill their own creations, many in fact relish the tactical challenge of taking on their own designs, or the roleplaying fun of dramatically switching viewpoints.
Plots and Villains: Although killing adventuring parties or sewer guards is fun for a one-off, a successful underground campaign needs much more than that. So what threatens the underworld? The first answer is anything that threatens the city above – the sewers are just as screwed as the manor houses if a gate to Hell opens in the town square, after all. Indeed, one of the key themes you can play up with whatever plot you choose is that the underworld and the overworld are inviolately linked, in a symbiotic relationship, and may even have to help each other to survive the approaching doom. As for what doom to choose, there are plenty of city adventures out there to plunder, just as long as they don’t rely on the PCs attending any balls or council meetings or suchlike – although figuring out how to crash such a party could be as much fun as figuring out how to crash a goblin festival.
Sources: This one takes its ideas straight from roleplaying, so other media sources are few. Underground cultures do appear in many stories, and although they are often under our modern cities, they still make good inspiration. Jean Pierre Jeunet’s film Delicatessen has some cool post-apocalyptic Mole People, Neil Gaiman’s Neverwhere is a dark mirror of the London Underground and Luc Besson’s Subway does the same for the Paris Metro, sans the supernatural. Many horror movies have utilized the classic CHUDs (Cannibal Humanoid Underground Dwellers). Meanwhile, for a more left-field source, watch The Matrix again, because tapping into that program throws the heroes from a dark, underground world into the chaos of a big, brightly-lit city, where anyone can be a threat, and you often have to bolt down the nearest exit.
RPGs: City guides are de rigeur in RPGs; most every fantasy RPG has them, and said cities almost always have an undercity as well. Recent epic works like Ptolus and the World’s Largest City certainly have plenty of room to adventure bottom-up instead of top-down. Actual city adventures are less common, and ones which can be reversed fewer still, but they are out there. The classic Warhammer adventure Shadows over Bogenhafen could be run entirely from an underground perspective, as could Green Ronin’s Freeport Trilogy. Finally, when it comes to viewing things from the other perspective, the essential texts are John Wick’s Orkworld and Chris Pramas’ Ork! Although they are both out of print, either are worth tracking down. Failing that, pick up Guide to the Underdark and make yourself some drow - with or without paired scimitars.
