What would be in an undercity in a low fantasy game? Last game

>>50142530
Cultists&other scum of the earth, bored young nobles hunting the most dangerous game, restless dead that has been thrown down there after keeping them locked up became too much of a pain in the ass.

>>50142530
In the dark depths of the sewers is a colony of men with all they own stripped from them. They've become so destitute that they're shunned from the very surface. All they have are the rats that live around them. The rats will never reject them. They love the rats. This devotion to the rats has led them to change, looking almost vermin like, and being very skittish and untrusting. But if you have nowhere else to turn they will welcome you. So long as you love the rats...

>>50142530
Look into real life examples - the catacombs of Rome and Paris, the Seattle underground, for example - research those and see how they were used, by whom, why and how they were constructed, etc.

So from those off the top of my head,

>Hiding place for persecuted minority/religion
>Booze/other outlawed substance runners creating tunnels
>Abandoned storefronts and housing

Of course, there's also the various fantasy setting possibilities, though most of these are most likely too high fantasy for you -

>Vampire lair, but of reformed vamps, a la discworld, drinking only donated or animal blood
>Secret Society goodness
>Crypts are always fun. You know what's in crypts? Loot as a continent carrot for your players. You know what's also in crypts? Skeletons, ghouls, etc - all manner of fun things.
>Irate ghosts that try to get players to mess with the graves of other ghosts (note, this is paraphrased from a Witcher 3 quest)
>A crumbling wall can be broken down to reveal an entrance into a long dead mage's basement, with appropriately bizarre experiments left behind.

>>50142530
troglodytes

>>50142530
well if you have Beastmen of any sort in your setting, Rat-men would be a good choice(as would Serpent-men or Frog-men)

>>50142530
An expedition lead by a band of Scholars, they were going to find out just how this city was built, when and by whom. Unfortunately they've gotten rather turned around and they're not sure how long they've been underground, their supplies ran out a while ago but there's fungus on the walls that's proven highly edible. They can see in the dark too, and the things they see don't bother them as much as they should.

Ruins from the civiization before the city. For low fantasy this just means the founders conquered an existing city, castle, temple etc and built atop the ruins, but there are ways down into the old foundations.

>>50142530
Undead ooze hobo thieves, obviously

>>50142693
Wait are they undead ooze that steal hobos? Or hobos that steal undead ooze?

What undead that steal ooze hobos?

>>50142709
Mayb they're just normal undead hobo thieves, but are already oozing a little

>>50142709
This man is asking the right questions.
Why does this undead ooze steal hobos?
Does the hobo need to steal undead oozes, or does he do it for fun?
Is there a preference?

>>50142530
Secret societies. Many of them date back to the when the old city was still above ground. It would be easier for them to meet above ground, but tradition dictates they continue to make regular treks into their underground meeting places.
Bands of orphan children. Many of the tunnels are homes to them. Far from the reach of well meaning adults who might try to restrict their lawless freedoms.
A haunted area. Bitterly cold and filed with pained moaning. (or maybe it's just the wind?)
Tainted men. Perhaps they have been struck by dark forces, perhaps just by some strange illness. Either way they have been warped and are best avoided.
Sewer pickers. Some choose to live underground and pick through the waste that flows down from above, hoping to find lost currency and other precious things.
Spies and counter spies. Agents of foreign powers seek to map the undercity, hoping to find secret paths to move an army into the cities heart. Agents of the local lord work tirelessly in the darkness to foil their attempts. Neither side has any idea if the path even exists.
Immense blind rats. They live in the deepest parts of the undercity. What do they eat? Wise men say there must be an ecosystem of blind animals to support them. The cities parents are more inclined to tell their children that they prey on disobedient youths.