Creating the "Deepworld"

Essentially, the Deepworld refers to the collective subterranean post-Cataclysm world, sorta like the Underdark from D&D. This would be a future project to support characters like Troglobites/Dwarves and Rats. The idea is to create an environment in which a character would rarely, if ever, have to go into that horrible bright-and-burning Overworld.

If someone can come up with a better name than “Deepworld”, my Enhanced Hearing is ready.

The first thing that’s needed is Food. You can’t grow plants without food, so you’re limited to finding underground water sources and hunting Ants. I suggest that the player is able to plant and grow mutated strains of fungi (not Mycus, naturally) that’d grow underground in the dark, and in cool temperatures. Plump Helmets, if you will, to take advantage of that Alcohol Metabolism that Troglobites haves.

My second suggestion would be to increase the amount of below-ground caverns, similar to what’s already happened with the subway/sewer updates. Possibly allow wildlife to respawn, so characters can eat respawning supply of sewer rats to sate that carnivorous hunger.

Anyone else have any ideas?

I have ideas for either ‘biomes’ or specific areas of the map. Possibly the overall name too:
Hel (The second l is for losers.)
Shadow Caverns
Mushroom Under-Plains
Abyssal Canyons
Forgotten Ruins

Ideas in the past for ‘Nether’ Mutantion trees. Probably extra helpful in some cases down here.

Details of each:
Hel: Filled with lots of lava rivers and lakes. The inhabitants have mutated to allow survival in the intense heat. When in this area, it is extremely hot, but to give the player a reason to go in there, there could be special rare loot or something. One thing is possibly a thermal plant which contains heat-resistant gear and mutagen relative to that. Maybe Bionics that allow resistant to heat as well. Also flamethrowers. Because fire.

Shadow Caverns: Crap tons of those shady zombies. Zombies miners which provide a mining helmet, potential batteries from them, and a pickaxe if killed. However, mining is hard work and thus they have strong muscles despite the rot (Imagine a slightly weaker version of a zombie brute). Pools of sketchy-looking water appear on occasion, which totally don’t have mutated water-related creatures.

Mushroom Under-Plains: A wide space of underground land. Pillars of stone in various places hold up the ceiling. Don’t destroy them, it’s a bad idea. Glowing mushrooms of different colors and sizes light up parts of the caves. Acid Pools sit around, and acid related zombies and/or fungal monsters are plentiful. The fungal enemies, unlike above the world, are much more territorial, and don’t expand as much. Rare ruins will sit around, providing useful shelter and some strange and potentially odd loot.

Abyssal Canyons: Stretches of canyons, some big and some small appear on occasion. Don’t jump down, since their might not even be a bottom. Partially broken wooden bridges cross the canyons. Sometimes has a ‘toll house’ nearby, where only a few randomized zombies spawn inside.

Forgotten Ruins: Along your travels you may find what appears to be the towns of a forgotten people. Whether they were human or not, you will never know. However, while loot is plentiful, so are zombies. The thin alleys and streets, rubble from cave-ins from long ago, and other blockades limit you ability to escape if you walk into the wrong place.

I feel like the main thing you need is a reason that these underground areas even exist. I’m not saying it won’t work, just that you need some reason for them to exist.
IRL we have (sometimes very large) building basements, underground facilities, mines, and natural caves. There are examples of a number of these in the game now, but what you’re describing is something much more extensive.
Rather than looking to underground areas, it might be productive to consider alternatives like stable portals to other regions that happen to be underground (or not, maybe they’re on the surface too). If you end up visiting another world, well then the sky’s the limi… wait, the ground’s the limit with how much you can add.

OOOOO! I’ve got a great idea for this! It is still (I think) thematic for the game, but adds considerable amounts of extra lore and gameplay. Here it is:
–What if the tears in reality that bring forth the monsters was this ‘deepworld’ that we are talking about? I kinda like to image the idea of the Nether in Minecraft, where there is a seemingly endless amount of stone up and down. Perhaps the deepworld could be filled with lots of late-game stuff, as well as challenges for it. I provides limits as well, as few places in there are big enough to support deathmobiles, and light is often lacking. This world is far different than ours, and it bends the knowledge of what we thought to be true, similar to how The Blob provided unique changes impossible any other way. The precursors of this world are long gone, but their foolish endeavors for knowledge and progressing is still shown. They made The Blob and all those Fungal creatures, as to how, we don’t know. They possessed seemingly impossible technology in the ruins of their cities, which are impossible to replicate. However, these devices may just be what humanity needs to survive. To rid themselves of The Blob which infected the world, and bring back civilization.
–This would be a massively long project to do, but I’m sure it could be. And I very much hope something like this will be added one day.

Alternatively, the Blob has slime pits, the fungals have towers, ants/bees have hives, the only faction without any real base is the Nether creatures. You could just make the bottom few layers a continuous set of tunnels full of nether creatures and their various stuffs. Loot, challenges, captured people, etc. You could have the occasional tunnel to the surface so people could get down there easily, and the amount of nether creatures down there could suspend the laws of reality, so you could do pretty much whatever you wanted content wise.

You could make use of those unused Hellmouths and say they’re entrances to hellscapes inhabited by Nether Creatures.

I feel like the main thing you need is a reason that these underground areas even exist.

Some ideas:

  • Giant worms, like those on the surface
  • Giant-er worms, making thicker tunnels. They died because around day 5 AC (After Cataclysm), a mysterious event killed off all creatures larger than 1 tile
  • Portal opening in the middle of solid rock, turning it into a cavern, then closing
  • Some sci-fi thing that also creates fumaroles
  • Blob tunnels following sci-magic ley lines or whatever they use to generate their infinite energy
  • Shoggoths building underground cities for their flying polyp masters, before figuring out that polyps don’t really like Prime
  • Tunnels created by Gov’t Chinese spybots
  • Tunnels created by escaping prisoners
  • Giant moles digging giant tunnels in search of giant worms
  • Underground giant wasp nests
  • Triffid home tree roots, later emptied from inside by some otherworldly parasite (or just giant termites)

wait, is this something being actively worked on or an idea the op had?

The latter. I’m trying to put forth ideas that’d help support a certain class of mutants, similar to how overhauling underwater will support Fish/Cephalopod Mutants.

What about making labs the go into a big, underworldesque cave system? The labs would throw their failed experiments in there and that would have created a whole mutated, twisted ecosystem without the scientist’s knowlegde, and with the Blob appearing in there it would have mutated dramatically, making the whole place a hellscape.
maybe you can even add portals around that spawned with the experiments that make reality rip apart and lava appear out of nowhere and slime just drool everywhere, making the caves even more impossible and threatening and filled with twisted creatures and hell enemies as you move on?

just trying to get ya inspired!