Underground Cities

      Once again, we are proposing an underground city.  Why?  Because they are an iconic fantasy setting.  Go out on the internet and there are a bunch of people who will tell you it cannot be done.  They have some valid points, so let’s address them.  (Warning!  We hate when people tell us we can’t do something.  It is simply a challenge to prove them wrong!)

     The first argument is that the air will go bad.  We have often used Mammoth Cave in Kentucky (USA) as an example that we can build our cavern system from.  Sure, it is the biggest in our world (probably), but it is real.  Mammoth Cave has visitors in it every day, and none of them have ever suffocated.  Why?  Because it has more than one entrance and the air moves through the cave.

     Sidetrack:  We love caves and have explored them, visited them, even slept in them.  Rarely has claustrophobia been an issue.  One time, one of our people was in a cave where the passage became pretty narrow.  A young boy got nervous and stopped, causing a bit of a “log jam”.  When the number of people in the tight tunnel caused the breeze to stop, that’s when others started getting nervous.  Did any of them feel the breeze before?  No.  But they felt when it stopped.

     OK, back to the main point.  Let’s assume that you did need to add ventilation.  One of our major magitech devices (check out All About Magitech) is the dwarven enchantment perpetual motion.  The most important usage of the perpetual motion devices is the exhaust fans from the dwarven mines.  There are multiple entrances to their underground city.  There are forges set up beneath one of the major shafts going up, and the heat of the forges (and the smoke) rise out of the shaft, creating motion in the air and drawing it in from other entrances.  Additionally, there are two main shafts that have perpetual motion fans blowing air out, creating these minor vacuums that then draw it in.  With or without magic, we think the air thing is not an issue.

     The skeptics then say that the people in the underground city would need drinking water.  These folks have probably not been to limestone caves, because the caves are carved by water, and the formations are formed by water.  Is this all the best drinking water?  Maybe, maybe not, but getting water in is not the problem!

     If there is a water problem, it is getting the water out!  Since many caves (at least limestone caves) have underground rivers, the problem is instead flooding.  Anyone who has done a cave tour has probably hit that spot in the tour when the guides point their flashlights at the wall and show you how the cave you are standing in was underwater during the latest flood.  Solving for that is an issue! but it is certainly possible to build your city in caves that have more caves beneath them to hopefully serve as a runoff.

      Related is the issue of waste.  Again, getting water in is not the problem, but instead getting stuff out.  Depending on the number of people and the number of underground rivers, this can be solved.  Take water from the river over there, and the downstream throw your waste into the river.  You might be polluting it for people in the next major dungeon over, but that’s not today’s problem.

     Depending on the strength of the river, all sorts of garbage might be disposed of in this manner, but as you will see soon, you might not actually want to dispose of the waste.

     How do you feed people in an underground city?  Mushroom gardens, right?  OK, here’s the problem.  Mushrooms need something to grow in - typically something like mulch or decaying plant material.  While mushrooms can grow out of the sun, they cannot grow where there is no food for them.

     What can you use?  Well, some of the waste might work.  Disgusting, yes, but it might be practical.  If you’re doing that you might not want to eat fresh mushrooms, but only mushroom soups, because you are going to want to boil those things after what they’ve been growing in.  Another means to explain the mushroom farms is to have someone on the surface shoveling “mulch” down a shaft.  This could be an easy way to supply the mushrooms with what they need to grow.  After the mulch has served its purpose, it is replaced with new mulch and the old stuff goes in the river or into the campfires.

     We think the actual answer is that you would only be living beneath the surface if there was something worthwhile down here.  Assuming that, there would need to be trade with the above ground world.  Food comes down and gold or gems go up.  This will usually work!  Coal or gravel won’t fund an underground city, but precious metals and precious stones will.

     Next issue - There’s no Vitamin D.  OK, assuming it is a fantasy city, dwarves and dark elves probably don’t need sunlight to get Vitamin D.  They also don’t suffer from any of the psychological impacts of never seeing the sun.  Maybe they need to eat a lot of fish or eggs to supply their vitamins, but this doesn’t seem unreasonable.  If there are some salmon who swim through the underground rivers to get to where they are going, then maybe they catch their own, but this is starting to feel a little far-fetched.  (More far-fetched than an underground city of dwarves?  OK, maybe not.)

     OK, that’s air to breath, water to drink, food to eat.  Those are some pretty major issues you need to plan for, but that doesn’t make the underground city all that different from an above ground one.

     Cost!  Why would anyone build an underground city when they could just live on the surface?  Well, we answered that one already - there is something down here they want badly enough.  They want it so bad that they were willing to go through the expense of building the city underground.  So, it must be valuable.

     Why couldn’t they live above ground and work below?  Well, we don’t know.  That is something you may need to answer for yourself.  We believe that it is too far to travel.  Depending on how long it takes to get to the work site, it may not be feasible to spend hours getting to the digging site only to work an hour and then spend hours going home.

     Let’s ignore “culture” as a question and mention why else:  Maybe it’s dangerous out there.  Maybe dragons fly overhead and breath fire on above ground villages.  This will have an impact on those friendly farmers above ground who were trading with the underground city, but that might still be surmountable.

     What if the above ground world is dangerous to you?  What if you’re a vampire?  What if simply stepping out into the sun could kill you?  Now, you have to go below.  OK, maybe you could live in a stone house, but that isn’t as safe to you as living below ground where the sun cannot accidentally get to you.  Nothing else changes.  You still need to trade in order to receive your food, but your reasoning for being below ground is different.  But not fully.  If you know you must live below ground - why not live below ground where there is a valuable resource?

     There is more to this concept of the cost of building underground.  What do you do with all the rubble?  This isn’t really an issue, because we know from Earth that major mines will often need to dump huge amounts of unwanted stone outside of the mine.  This might be an argument against hugely long tunnels linking continents, because then it takes far too long to transport the stone out of the tunnel, but for “mines” this is not a new problem, but instead one that has been solved by man long ago.  Still, you might want to have a massive gravel pile outside the mine to tell folks you thought about this.  It might even look like an ant hill, depending on who’s doing the digging.

      Last one - Light.  How do you see?  OK, of all the FRPG reasons not to have an underground city, this is the lamest!  Doesn’t every race but humans have some manner of see in the dark ability, at least they seem to in that main die-20 game with all the editions!  There are many ways to address lighting an underground city.  There could be luminescent fungi, only slightly science fiction.  Use of torches, candles, and lamps can be done.  It might require a bit more discussion of exhausting the bad air, but not much.  It also requires more trade than just the food.  Magical illuminations are expensive, but they assumedly last forever.  A couple of generations underground and the city could easily be lit by these.  Does your game have a continuous light spell?  Maybe in addition to the other civil servants, there is a spell caster (or several) who wander the city putting up these eternal light spells.

     We think all of this is pretty “low magic” for such a fantastical setting.  We haven’t even suggested using purple worms to dig the tunnels or elemental gnomes yet.  While it is true that living underground has its costs, it only seems like you have to put a short period of thought into handling the logistical issues and then get started.  But in explaining away these logistical issues, you are not only developing the city and its culture, but you might be figuring out what the next mission is, as the city might need some adventurers for help!

 

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     This post was written as part of The Depths of the World aka All About A Highest FantasyCampaign, the latest in our Small Bites editions.  Each Small Bites book looks deeply at one subject, a character archetype, a race/monster, a style of questing, or some other role-playing/world building subject.  This one is a fully detailed campaign including extensive exploration of the “tunnel world” far below the surface.  But it is never “just” a campaign!  It contains world building, game mastering, and a host of other stuff!

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