D&D 5E How do you make sewer dungeons believable?

[Eltab]

You know, when I first glanced at the thread title I thought it read:

How do you make sewer dragons believable?​

And thought to myself, "What is sewer dragon? Some cross between a dragon and a crocodile or something?"

Somewhere in its lineage is a splash of Otyugh.
So it thinks of the sewer as a place to stay, not a place to leave.

 

[jasper]

This is a silly setting problem to have, but it's recently come up in my megadungeon game. Or more specifically, in the small town beside the megadugenon. How do you make sewer dungeons believable?

To the best of my knowledge, medieval sewers were little more than open air ditches. Rome's Cloaca Maxima is a good model, but it's the sewage system of a world capital. I doubt that my little dungeon-adjacent village could justify such an engineering project. So when you're in a village setting rather than a major city, how do you justify sewer dungeons? Or are you better off inventing some other kind of subterranean labyrinth and saving yourself the verisimilitude hassle?

(Comic for illustrative purposes.)

Players have to scoop the cats litter boxes. On a Nat 20 they get to take outside and toss into the alley. On a nat 1 it goes into their pocket.

 

[LordEntrails]

Reminds me of the urban legend of Giant Alligators in the NYC sewer system from people flushing them down the toilet.

Urban Legend? No way, they are real!

I knew a guy who had a friend on Facebook who knew a guy who lived next to a NY city worker who had a co-worker who lost an arm to one! I swear, it must be true!

 

[R_J_K75]

Urban Legend? No way, they are real!

I knew a guy who had a friend on Facebook who knew a guy who lived next a city worker who had a co-worker who lost an arm to one! I swear, it must be true!

Im sure he replaced the arm with a hook for a hand too right?

 

[nevin]

Well I wouldn't have sewer dragons, I might have a really big lizard that can spit acid and if the party decides it was a sewer dragon I wouldn't argue with them.
I had a party once run into demon touched, fire proof elves that they thought were Trolls. They got really upset when fire didn't work. To this day in my private campaign world the humans call those elves Fire Trolls because that's what the Paladin reported back to the King and the Church. I love little bits of flavor like that.

 

[Cap'n Kobold]

Like this:

Girl Genius

 

[Unwise]

IMC, the local town has a sewer system that they never really installed. The town is just built on top of another one and there is an underground river running through those ruins. It took little effort for them to just dig down and either drop into deep cesspits, or poop into the river. Of course, there are issues regarding the well coming from the same river as they fluff their waste into.

 

[Unwise]

<edit - oops duplicate>

 

[fba827]

Look at it as an excuse to tell a story as to why the village has one.

possible explanations for small village sewers

(1) long ago a gnome wizard actually stated in the village for ten years while recording laboratory experiments on local flora. He noticed the village had a terrible flooding problem or stench problem and just to appease himself, he used magic to carve out rough sewer ways to route water and ease the problem that was otherwise going to just bother him for years. After the gnome left with the end of his research, the villagers over time would straighten up the rough sewer walls and even expand sections to cover more of the village because they found it helpful

(2) the village was beset upon by a Minotaur bandit who would return on every autumn equinox and ravage the village. They needed a trap, starting with a simple hole in the ground, and this idea morphed in to inclusion of winding tunnels and also to allow villagers to dispose of waste such that it would flush through the tunnels... and thus the next attack by the Minotaur, he was tricked in to the trap. Some say its ghost still haunts the tunnels beneath the village....

(3) ‘long ago’ the village is In a region governed by a political power that was trying different sewer designs for a big city. But rather than waste expense on prototypes beneath a big city he had his people try different designs beneath different small villages. So they could ‘beta test’ the best features to eventually be used in the city’s own design

(4) it’s tunnels from a large burrowing creature that is no longer there and the village was build above these now abandoned tunnels. When the tunnels were discovered the use as sewers was a no brainer. What no one knows is that embedded in one of these old tunnel walls are the eggs from the tunneling creature and these eggs take 500 years to hatch... and it’s about that time

(5) a race of creatures that prefer underground (dwarf, gnome, drow, etc) came to an agreement with the original village settlers. One race would live beneath the village ( developing tunnels and such for their own use) and the other would live above the surface. They had symbiotic societies, providing resources to each other. But something happened and the subterranean humanoids are no longer there. The tunnels - with only very minor modifications - were turned in to sewage ways.

 

[Fauchard1520]

combine the sewers with the local graveyard tomb plus add in bandits or monsters have dugout a liar. Maybe it was built on an old mine that got flooded

Heh. I like that this has a built in "angering the spirits" plot. I know I'd want to haunt the jerks pooping in my grave.