Underdark Encounters: The Rotted Expanse

For the past year I ran a D&D 5e game set in the Underdark, or at least my version of it that featured elements from Hot Spring Island sprinkled in. The players all played Underdark races and never once saw the sun (the one they saw when transported to Hot Spring Island doesn't really count) My players and I finished that campaign recently. There were magic eating constructs, evil deep gnomes monks, and medusa shock troops galore.

Along the way, I designed some fun encounter tables for the more dangerous regions the players traversed. Below is the table for one of my favorite regions: The Rotted Expanse.

Area Summary

Mushroom Men, meets Chernobyl, meets Salt in Wounds, meets that scene in Blade Runner: 2049 set in Dust Bowl Vegas. Three titanic beasts fought a battle, died and have been rotting ever since. In this section of the caverns is near impossible to breathe in unassisted as the air is choked with a yellow fog made up of spores and poison gases. The only things that thrive here are demons, rot, and Myconids. The myconids made the three slowly rotting beasts into their home cities and tend to be isolationist in nature. Occasionally, Underdark city states close to the Rotted Expanse send caravans through to trade with the myconids. These caravans are the safest way to travel as they provide breathing masks and strength in numbers. My players took part in one of these caravans.

Source

The Rotted Expanse Event Tables

A) Event (While traveling the following occurs...)
roll 1d10
1. A sinkhole crumbles around the party
2. A thick spore fog lowers visibility to 10ft
3. An ethereal noise echoes throughout, Wis Save become lost and confused.
4. A sickly sweet smell surrounds you, Con Save or suffer exhausting hunger
5. A field of exploding spherical mushrooms
6. Giant pillars of bone jut out of the mottled ground, The smaller finer bones litter the area around it.
7. A strong wind blows through, verbal communication, flight, and gaseous effects are near useless.
8. You pass a massive stone monolith glowing with red energy
9. Mushrooms begin to grow at an alarming rate, it becomes difficult terrain
10. You come across a failed drow colony. Buildings are covered in fungal growth

B) Monster (At the site of the Event you encounter..)
roll 1d10
1. A Mind Flayer researcher and his two pet Chuul
2. A skull obsessed demon bird named Gor.
3. Two ancient constructs carry a puzzle box through the wastelands. They appear to be following a preset path
4. Living whirlwinds filled with spores tear through the landscape.
5. A Myconid Merchant selling breathing masks and bone sculptures
6. Three tall ethereal antlered beings appear, they accept offerings for wisdom.
7. Giant mushroom dryads are participating in a neat little dance, they ask you to join.
8. A squad of myconids, dressed for battle is cresting over the hill.
9. A small garden of gargoyles, carved from bone, is set up in what appears to be an intricate pattern.
10. A looming silhouette is seen in the distance, a flat giant is making its rounds

C) Attitude
roll a 1d6
1. Hungry/Exhausted
2. Aggressive
3. Hunting for (creature)
4. Looking for (object)
5. In conflict with (roll B again)
6. Willing to trade/ distracted if unintelligent