Much ado about dungeons

[Celebrim]

To be honest, I'd never even thought about the idea that dungeons would need additional "venting" for breathing. Which makes me wonder, if this is true, how are the following places "oxygenated"? And these are honest questions, if anyone knows the answers...

I'll give it a shot.

1) The Catacombs under Rome

Rome has many catacombs, but each are relatively small. Ventilation is probably provided by the expediency of having multiple entrances over a comparitively small area.

2) Carlsbad Caverns

Carlsbad is huge for one thing. In general, cavern complexes are ventilated by 'breathing', in that a cavern complex generally maintains a fairly constant air temperature. When the outside air is warmer than the interior air, air blows out of the cave complex. When the outside air is colder than the interior air, air blows into the cave complex. This cycle often occurs daily in many caves. Carlsbad's ventilation problems are more complex than most caves though because Carlsbad naturally vents sulferic acid fumes. I'm no expert on Carlsbad, but I would suspect that there can be pockets of bad air in back areas of the complex where visitors would not normally go. However, given the massive size of the Carlsbad entrance I would suspect that there is alot of circulation going on, and the breathing problem is made easier by the fact that the fumes - being lighter than air - rise rather than sink.

Caves normally only have problems with 'bad air' if they contain so much life (and associated decay) relative to the amount of air flow, that carbon dioxide or methane pile up. Insects and other animals can be adapted to the oxygen poor environment, while it still being unhealthy and potentially lethal to humans. This is true of, for example, many caves in Mexico. It's also true of some caves with large bat colonies.

3) Derinkuyu, the underground city of Cappadocia

I was not even aware of the existance of this real world 'moria', and will have to give you XP for bringing it to my attention. So far as I can tell, the inhabitants of Derinkuyu built an elaborate system of ventilation shafts to ensure there would be air circulation throughout the complex.

 

[Jon_Dahl]

To understand more about dungeons is to visit them yourself
For natural "dungeons" I strongly recommend the true city of caves: Budapest.

It has over 200 caves and I visited Pál-Völgyi this summer. It was a real eye-opener and gave me lot of insight for running D&D.

One of the pics I took:

So you want to have a fight there? Good luck

 

[Jhaelen]

1) The Catacombs under Rome

Well I didn't visit the Catacombs in Rome, but I was in the Catacombs on Malta. They have air shafts. I guess those in Rome will have them, too.

For natural cave systems it depends on how they formed. But I'm not aware of any natural way to supply them with air except by being open to the outside at several points, even if the openings are just 'cracks'.
A party entering a cave with torches ablaze could be in trouble quite quickly because the oxygen is consumed faster than it can be replaced.

Anyway, in a magical world air supply shouldn't usually be a problem - the dungeon builder will have found some way to solve the problem, either by using permanent spells or introducing creatures that create oxygen in some way.

 

[megamania]

I love dungeon crawls.That having been said, there are two things about them that I have often wondered in the last 30 years that I've been gaming… …

25 years for me and yes I enjoy them also and have wondered about similiar things....

1. How do you breathe in them? Even modern mines need air vents of some kind. Where does the air come from for dungeons? …

1. 
   
   Depending on the dungeon's design and intention there can be air elementals with summoning occurring occationly, air vents built in, plants (like the surface world) that produce air or simpily... magic (mortal or divine)
   
   

   [*]Do they ever have a purpose other than being just complex cosmopolitain monster lairs? Do people ever make up real stories as to what purpose the dungeon "facility" is supposed to have, who built it, and why? What about the reason for there being enough treasure there to double or tripple the economies of most real-life medieval nations?

…

I do a lot of Eberron these days and there are many reasons for the dungeons existing....and as such allows for many different types of dungeons to explore. There are secret socirties and long forgotten races that built secure homes below ground. Others create these dungeons for isolation or self exile. Some it is a lab area for experimenting. These labs could be commercial (House Cannith or other Dragonmarked families) which have many designs and versions.

As for the treasures involved, I always thought of the gods looking for entertainment and tweak the dungeons to add incentive for explorers to come and check it out.

Maybe I should think less and kill more…

Evil DM...... When the DM smiles it is already too late....

 

[Celebrim]

Well I didn't visit the Catacombs in Rome, but I was in the Catacombs on Malta. They have air shafts. I guess those in Rome will have them, too.

I'm not familiar with either the catacombs of Malta or Rome, but I have a fair amount of knowledge of the Parisian ones and, at least in Paris, air shafts are a natural result of the most expedient quarrying technique. Typically, rather than extending the shaft horizonatally and then have to manuever the stone through the passages and up some human access point (which would have stairs and the like) and then back to the construction site, they'd drop a new vertical shaft near where the stone was needed. Then working from the base of the shaft they excavate new stone and lift the stone straight up through the vertical shaft using a simple crane. The result is that the quaries would have air shafts at many points.

However, I know that there are lengthy underground stone quarries in Russia that used completely different techniques. From what I can tell, these where so large (hundreds of kilometers ultimately) that they ended up working like a natural cave system.

For natural cave systems it depends on how they formed. But I'm not aware of any natural way to supply them with air except by being open to the outside at several points, even if the openings are just 'cracks'.

Hypothetically, a living cave which has a stream containing large amounts of disolved oxygen could release the oxygen into the cave system thereby replacing the need for an air opening. This could explain the presence of 'good air' on the other side of a sump, though in most cases I imagine that its really the cracks involved. However, I know that the opposite impact of a stream is certainly possible - oxygen poor water entering the cave air disolves oxygen out of the air faster than ventilation can replenish it. This is one of the three or so more important ways that you get bad air in caves. The third is having mineral deposites in the cave that rapidly oxide - iron rich much, walls rich in sulphur deposites. Deposition of oxygen on the cave walls can occur faster than natural ventilation replinishes it.

A party entering a cave with torches ablaze could be in trouble quite quickly because the oxygen is consumed faster than it can be replaced.

Open flames on the other hand are very good oxygen depletion detectors. Characters carrying torches would be warned quickly of bad air by observing that thier torches are burning unnaturally low. Aerosole tests like a cigerrette lighter are even more effective, and can be used to actually measure the amount of oxygen in the air, but I doubt such devices are common in most campaign worlds.

Relying entirely on artificial light - such as a magical flame or light source - is concievably even more dangerous because you'll get no warning until your Wisdom has already taken a big hit because your brain is starving for air.

Anyway, in a magical world air supply shouldn't usually be a problem - the dungeon builder will have found some way to solve the problem, either by using permanent spells or introducing creatures that create oxygen in some way.

This assumes that access to high level magic is something that is readily available. I suspect that for most campaigns, ordinary solutions are more dependable and easier to come by.

 

[Yesway Jose]

This is the one that has always bothered me particularly. Quite often you read the description of the dungeon and its crammed full of treasure, and everyone in the nearby town knows it is there, and the people of the town are actually of higher level than the PCs.

If the dungeon is well known, and the rumors of its treasure so easy to come by, and its inhabitants so weak in comparison to the vast wealth that they control, why hasn't someone come along in the past X centuries and claimed the treasure? Why hasn't some other higher level adventuring group come along and cleared this place out quite easily? This is particularly true of low level modules where some local lord and two score mercenaries would quite possibly more effectively dispatch the inhabitants than the party would. This is even more true in settings like FR where it seems everyone is high level.

And where did this treasure come from in the first place? How was this small community so secure in its wealth, that it decided to bury millions of dollars worth of treasure to adorn its dead? If they were Egyptian in outlook, why didn't the original tomb builders rob the tombs Egytian style? If the community persisted for a long time, how did they sustain the economic drain if the treasure wasn't in some fashion being returned to the economy? Why did the heirs of the dead not take their inheritance? Why didn't the original inhabitants take the treasure with them when they moved out? Why haven't later inhabitants found the treasure and either spent it or moved it to a more secure place? Why is this magic sword just lying here/in a chest/stuck on the wall, when the bugbear in the next room is perfectly proficient in its use? I take a certain satisfaction in designing a dungeon in such a way that I know most of the treasure won't make it out, because it gives me some justification for why the treasure was there in the first place.

Why are dungeons almost in pristine condition before the PC's arrive, and totally wrecked afterwards. You mean no adventurers have come along in the past 10 centuries? If not, then why not.

I don't want to spoil it for anyone who hasn't read the novel, but there is a story in which once-empty catacombs are suddenly and surprisingly inhabited.

I would enjoy playing a campaign with a semi-realistic plot device in which the world is relatively mundane and Dark Strange Things have only recently been appearing. Common folk assume incorrectly that they've always been there lurking in the wilderness, but sages ponder: if that's true, then why haven't monsters emerged decades or centuries ago and overrun the entire land? The truth may be that Hell and the feywild and the shadowfell are all phasing into the world. Or maybe the Old World literally vanished and is now realigning into the present time. Dungeons once sealed are mysteriously unlocking or materializing as if they've always been there. This theme can be worked into the entire campaign and the big picture emerges in the Epic tier (or maybe never at all and remains forever mysterious).