Underground Labyrinth
7
Designed for 4 characters of level
Underground Labyrinth
Underground Labyrinth is balanced for 4 characters of 7th level and is intended to be used as part of the D-List Kingdom campaign but can be adapted to be a one shot or part of a different adventure.
Location Map
Location Overview
Below the Harpy Mountain there is a collection of tunnels that were carved during the early days of settlement on the island and beneath the tunnels is a much more intricately carved labyrinth in which holds many secrets.
Quest Goals
Defeat the Elementals or fix the switchboards to remove them
Escape the Labyrinth without succumbing to the Shadow Ghoul or Juri Gumo
Stop the Gate Guardian to exit the Labyrinth
Arrival
The adventurers arrive to see a dimly lit cavern ending at a large stone wall, from floor to ceiling the wall stretches the landscape and the characters can find a 10ft square entryway that leads to the labyrinth. The wall is impervious to all damage except force damage has a damage threshold of 20 to create a 5ft hole in the wall, this would require a lot of resources and is not necessary for this adventure so advise players that this approach may not work once they have attempted once or twice.
After resting and entering the labyrinth, have the players roll initiative (during initiative characters can not move diagonally in the labyrinth even if you usually allow this movement). The labyrinth has 10 ft wide and tall corridors and a character who succeeds on a DC 14 history check can tell that the walls are not in fact stone and are carved from bone like material, characters who have discovered the Whale Fall plot are able to understand that this labyrinth must have been carved from the bones of the Citadel Whale.
Locations
Monster Map
L1-L3 - Switchboards
Each of the switchboards controls one aspect of the labyrinth and, once the characters succeed on a DC 15 check using the required tools, also removes the related elemental from their place and sacrifices them in L6 - Gate Guardian. The switchboards, avenues, related elementals and tool proficiencies are:
L1 - Vents - Air Elemental - HVAC Tools
L2 - Wires - Thunder Elemental - Electrician’s Tools
L3 - Pipes - Water Elemental - Plumber’s Tools
When characters reach the switchboard they must use the Utilise action and succeed on the related check at which point the respective elemental in the dungeon will be removed which you can describe as being sucked away down the appropriate avenue above.
While characters will likely not have proficiency in the appropriate tools, you can have the players describe an incident in their character's backstory related to the avenue. Reward players with temporary proficiency for good improvisation but never punish players if they are not able to come up with something on the spot.
L4 - Spider’s Den
This area houses the Demonfeed Spider who if defeated will spawn from an egg again on the next dawn. A short rest may be advised after defeating the spider but the respawn will stop players from taking too long in the dungeon (if characters decide to take a rest you can pause initiative until the rest is over).
L5 - Shadow Wall
This part of the wall contains the Wall Shadow and any creatures who get too close will be attacked by the creature. If the creature manages to bloody a player, it turns into the Shadow Ghoul and will attempt to finish off the player but will only do so if there is no light in the area.
L6 - Gate Guardian
Once the characters exit the labyrinth part of the dungeon, they are in a closed off larger area with a large construct with elemental runes carved into sections of it. If the players completed any of the switchboards in L1-L3 the appropriate section of the construct is lit and it has the related power in its stat block active. The Gate Guardian will attack and seal off the labyrinth once all the characters are within 15 ft of it and not stop attacking until defeated.
Leaving the Location
Once the Gate Guardian is defeated...