Sewers, smuggler's tunnels etc

[EricW]

On 4/25/2019 at 10:20 PM, Joerg said:

The Krarsht-supported criminal groups may have uneasy alliances with other counter-social groups, and a failing alliance with e.g. a gang of Lanbril thieves may result in such information seeping out, or at least being spied out by former allies taking a closer look at those guys, following the money and/or the magic.

The fence to whom Lanbril sells stolen goods might well be a Krarsht worshipper, maintaining a public facade of respectability. From Cults of Terror;

Quote

Since the Dawning, worship of the Waiting Mouth has infested many civilisations. This religion appeals to bureaucrats, conmen, unscrupulous traders and those in general whose foremost desire is to be on the side of power always; the cult of Krarsht teaches many skills and rationales that the ambitious find useful. The cult can conveniently do away with rivals and enemies, as the Mouth needs occasional sacrifices, but not so many that the wrath (or even the curiosity) of the public is aroused. Cult members are expected to try to be active in local economies and politics. Others may find success in underworld dealings. Frequently cult members serve as a clandestine network making any service or item available at a profitable price

It could even be fun to deceive PCs into forming a relationship with a useful supplier of illegal services and information, then when they are utterly dependent, taunt them with inconclusive evidence (supplied by a captured enemy) that their "friend" is actually a chaos cultist.

If challenged the "friend" would deny everything, maybe ask the PCs to come back later that night to help work out which assistant is the real chaos infiltrator. Please don't bring Storm Bulls, they would tear up the shop and ruin his livelihood even if they didn't find anything, he has a reputation to uphold!

Edited April 28, 2019 by EricW

[Puckohue]

Thanks everyone for inspiration!

[Joerg]

On 4/25/2019 at 9:01 PM, Ian Absentia said:

With regard to enclosed sewage tunnels, GMs should be encouraged to keep a variety of gases up their sleeves. Confined spaces are great places for the accumulation of gases and terrible places for people to crawl about in.

Generally true. CO2, CH4 and H2S are naturally formed by decay, usually through the agency of anaerobic metabolism.

On 4/25/2019 at 9:01 PM, Ian Absentia said:

Carbon Monoxide - Just plain poisonous and all-too-common. Slightly lighter than air, so it rises toward breathing height.

True on all accounts, but this gas is only produced in combustion processes with insufficient aeration. In addition to being toxic by bonding permanently to hemoglobine, the gas is also flammable. It burns with a blue flame, as you can observe at the lower edge of a candle flame.

There are no bacteria that emit carbon monoxide to the atmosphere - this stuff is still reactive and contains potential energy, and nature doesn't usually waste energy when a bunch of rivaling organisms breaks up organic matter.

There is still a chance to encounter this gas in tunnels, if people have lit a significant fire down there (e.g. to exert thermal stress on the rock to make it break away easily when digging a tunnel). Possibly also in the aftermath of the swamp gas explosion in the tunnels.

You'd have problems breathing such atmosphere anyway, because of the soot and the low oxygen content.

 

On 4/25/2019 at 9:01 PM, Ian Absentia said:

These gases don't accumulate at dangerous concentrations everywhere in sewage tunnels, but they're common enough to make me give the ending of The Shawshank Redemption the hairy eyeball.

Sewage tunnels are quite likely to transport water similar in quality to the rivers downstream of industry in the sixties or seventies. They are not the equivalent of modern waste water leads that are laid independently of rain water, transporting organic freights in the range between 200 and 6000 mg chemical oxygen demand per liter. (In comparison, milk or liquid manure or the content of biogas plants has easily beyond 10000 mg/l COD.)

In my professional opinion, only the late Iron Age/Imperial Roman sewers fed by those public loos or waste water downstream of tanneries will have come anywhere into the neighborhood of modern day communal waste water. If only for the simple reason that you need lots of at least moderately fresh water in order to keep such cloacas workable, as the freight of human waste requires quite a bit of mechanical pummeling to distribute into the liquid. Septic tanks show you quite drastically what happens to the stuff when there isn't that much movement in the water.

On the other hand, when you have less agitated sections of underground waterways, then the sludge can settle down and continue its biological processes. Unless disturbed, a lot of gas may build up in that sludge that isn't usually given off to the atmosphere. But have a merry chase wading through that kind of sludge, and nice, tennis-ball sized bubbles of miasma will pop up and deliver all those gases even into a previously well ventilated tunnel.

In this context, here's a couple of fun facts about hydrogen sulphide. Yes, in small amounts, that stuff reeks of foul eggs (although to the modern human, foul eggs reek of hydrogen sulphide). The higher the concentration in the air, the less intense this smell gets. Medium high concentrations remind slightly of the smell pork gives off in a hot pan. At some point, your nose won't register H2S any more. That's roughly the concentration that is acutely toxic (btw a concentration one or two orders of magnitude lower than the lethal concentration of cyanic acid).

 

In Glorantha, the odors of decay (including ammonia, amines and hydrogen sulphide) are associated with darkness entities and the element of darkness. As a consequence, I would expect troll physiology to be a lot more tolerant to these gases, and the same goes for trollkin. It should be  possible for trollkin to retreat into tunnels that would poison or suffocate human pursuers.

 

On 4/25/2019 at 9:01 PM, Ian Absentia said:

Used sparingly, they make great natural traps to employ against intrusive adventurers. Ventilation is your friend.

There is a sweet spot between toxic and breathable that likes to go boom in the neighborhood of open fire (such as oil lamps, candles or torches).
Just a little ventilation might be less of a friend than you might think. For more info on this topic, I suggest a read of "Thud!" by Terry Pratchett rather than some dry safety instructions.

 

Mostali ventilation shafts may have worse surprises, basically imagine the full selection of D&D breath weapons as possible effects of their alchimical/industrial exhausts. Or combinations thereof.

[Ian Absentia]

1 hour ago, Joerg said:

True on all accounts, but this gas [carbon monoxide] is only produced in combustion processes with insufficient aeration.

I see where we were at odds.  I'd wandered off trudging through sewers in particular and into general "dungeon" tunnel environments.  In addition to combustion (from, say, adventurer's torches and cooking braziers), CO is also found in volcanic gases that might be encountered in some scenarios.

1 hour ago, Joerg said:

There is a sweet spot between toxic and breathable that likes to go boom in the neighborhood of open fire (such as oil lamps, candles or torches).
Just a little ventilation might be less of a friend than you might think.

Too true -- there's an unfortunate overlap between the amount of oxygen we need to breathe and the amount needed to make certain gases explosive in the presence of ignition.  I should clarify that lots of ventilation is your friend.

!i!