The World Below
Adventure Seeds
The Last Warm Stone — A cavern’s communal heat stone cools for the first time in living memory. A fissure beneath it leads to a warmer chamber, but opening a passage could divert the heat from another settlement.
The Harvest Bell — Farmers hear their harvest bell ringing from deep inside an unworked wall. The sound marks the movements of a burrowing creature whose route makes the fields fertile—and whose next passage will run beneath their homes.
The Guest Chamber — A newly excavated room has beds, supplies, and a carved welcome naming the characters individually. Its builders could not have known them; the room’s stores would nevertheless save their community this Kalm.
The Price of Quiet — A tunnel used for generations becomes unnaturally silent. Travelers emerge unharmed but unable to recall the promises they made inside it, including a crucial agreement between two settlements.
The Turning Bridge — A stone bridge rotates a little farther each Kalm. Soon it will connect an isolated community to a rich trade route while cutting its only safe path to drinking water.
Ash for Tomorrow — An alchemist finds that ash from a particular cavern improves failing crops. Collecting enough requires extinguishing the slow fire that has kept dangerous creatures away for decades.
The Unspent Rations — A lost pack returns with every ration untouched and its members well fed. They refuse to say what fed them until the settlement agrees to send no hunters into the cavern they found.
The Stone Orchard — Mineral growths bearing edible fruit appear where quarry workers have been dumping waste. The harvest could end a shortage, but each fruit removes a little more strength from the stone supporting the quarry roof.
The Second Spring — Surveyors locate a clean spring beneath the town’s old one. Its water rises only when the upper spring falls, suggesting the community must choose which neighboring settlement receives the overflow.
The Keeper of Spores — A cultivator disappears after developing a fungus that can feed a settlement through famine. Her notes show that its growth also consumes the material used to seal homes against toxic air.
A Door for Every Dawn — A sealed passage opens briefly at the start of each Dawn, offering a safer route to distant markets. Traders want it widened; a returning traveler says the passage closes early whenever too many cross.
The Weight of a Map — Two accurate maps place the same cavern at different depths. The discrepancy could expose an unknown route, but the miners following one map have begun breaking through the ceiling of an inhabited refuge.
The Cartographer’s Debt — A mapmaker sold exclusive access to a shortcut before discovering that local families rely on it for evacuation. The buyer intends to install a locked gate, and the sale is already binding.
The Path That Remembers — Footprints appear ahead of travelers on a newly opened route, showing exactly where they will step. One set abruptly ends at a safe looking patch of floor; another leads straight into a guarded camp.
Three Marks on the Wall — Explorers find the same three survey marks in caverns days apart. Following their intended order reveals a route built to move something enormous without passing near any settlement.
The Breath Between Caverns — A useful new tunnel has a steady breeze, then begins drawing air away from nearby homes. Closing it restores the air but traps the workers who established the far end.
The Lantern Exchange — Travelers leave working lanterns at an unattended alcove and find different ones waiting on their return. The replacements illuminate hidden hazards, though their light also makes the bearers visible from far across the dark.
The Fifth Bearing — An old compass acquires a fifth direction near a settlement’s foundation. Following it leads to a buried worksite whose abandoned supports have held the settlement steady for years.
Below the Toll Gate — A toll keeper’s route becomes impassable, and trade shifts to a narrow crawl beneath it. The keeper asks the characters to reopen the old passage before the merchants discover why the new one remains safe.
The Passage of Small Things — Food and tools vanish from guarded storehouses through cracks too narrow for a person. Following the theft reveals a small community that has survived unnoticed inside the walls—and now needs more than it can take.
A Roof of Shells — Builders discover that the hard layer shielding their settlement is a vast abandoned carapace. Its former occupant is gone, but something has begun repairing the damage left by excavation.
The Borrowed Defense — An engineer offers a barrier that will keep raiders out of one settlement. It works by opening an easier approach to its neighbor, whose leaders have not been told of the plan.
The Militia’s Practice Ground — Militia drills repeatedly trigger tremors in a supposedly stable cavern. Cancelling training leaves the settlement exposed; investigating the tremors may reveal a defense hidden beneath the practice ground.
The Watcher’s Blind Spot — Sentries can see every approach to town except one patch of empty floor. Nothing has entered through it, but supplies placed there disappear only when the sentries look directly at it.
The Siege Pantry — Workers uncover a sealed storehouse stocked for a siege that never happened. Its food is still usable, and a nearby community claims its ancestors filled it under an agreement no one recorded.
Terms of Shelter — A neighboring settlement offers refuge during a predicted cavern collapse. In return it wants the characters’ people to abandon their claim to their current home, even if that home survives.
The Apprentice’s Wall — An apprentice’s crude reinforcement saves a workshop after its master’s celebrated design fails. The master demands it be removed before other builders copy it; removing it may bring the roof down.
The Work of One Hand — Repairs throughout a settlement bear the same distinctive tool marks, though no one authorized them. They are sound repairs, but together they prepare the streets for a purpose no resident recognizes.
The Guild’s Empty Slate — A guild delivers a blank record slate to the characters’ settlement and requests testimony from everyone who lived there during the last Kalm. Someone has erased its account of that period from every other archive.
The Record of Tomorrow — A ledger lists next Kalm’s expected losses beside preparations that could prevent them. Its figures have been reliable before, but following them would mean withholding aid from people who need it now.
The Child Who Counts — A child correctly counts people in sealed rooms and across stone walls. Their count of the settlement is one higher than every census, and it rises whenever the community expands.
The Inherited Task — A dying delver entrusts the characters with a maintenance duty their descendants have performed for generations. The mechanism still works, but no one knows whom it protects—or what happens if it stops.
Names on the Uncut Stone — Miners find names carved inside rock no tool has touched. Some belong to the living. The characters must decide whether to warn those people before learning why one name has been deliberately scratched out.
The Debt of Descendants — Two families dispute a labor obligation agreed to by ancestors neither remembers. An old worksite can settle what was promised, but it may show that both families have been paying the wrong settlement.
A Kalm Without Celebration — A settlement cancels its customary Kalm gathering after several residents report identical dreams of the feast. Staying apart may keep them safe; it also prevents the decisions needed to prepare for the next disaster.
The Feast Table’s Fourth Leg — A communal table starts leaning whenever a seat is left empty. Its stone fourth leg extends into a passage below, where a long hidden chamber is slowly taking the table’s weight.
The Two Refuges — An excavation exposes adjoining shelters with space for only one settlement each. Both neighboring communities helped fund the dig, and a Kaos storm is approaching before either can build more room.
What the Rescue Cost — A party saves stranded travelers with an improvised route, then discovers that their excavation has made a nearby settlement’s food stores accessible to burrowing pests. The rescued travelers can help repair it, if they are asked to risk the route again.
The Settlement That Stayed — Refugees report that their former home is still intact after a catastrophe, but no one there will answer visitors. The characters find the residents maintaining its defenses for people who have yet to arrive.
An Offer of Apprentices — A prosperous community offers to train the characters’ young specialists for free. Its graduates return capable and loyal to home, but all insist on directing future excavations away from one particular stratum.
The Honest Hunter — A hunter brings back enough food to end a shortage and openly states where it came from. Harvesting there again requires entering a creature’s breeding ground, and the hunter believes the settlement should make that choice together.
The Beast at the Boundary — A predator kills anyone crossing between two caverns but leaves their inhabitants alone. Both settlements want it slain; removing it may let a more dangerous species spread between them.
The Unwanted Antidote — An alchemist produces an antidote for a common cavern toxin. Those it saves begin noticing a second, previously harmless substance in their drinking water, forcing a choice between treatments and a new water source.
The Price of a Cure — A healer can treat a spreading affliction using a mineral found under the settlement’s supports. The characters must find another deposit or determine how much stone can safely be removed.
The Storm’s Edge — A Kaos storm repeatedly stops at the same wall. Residents mine shelter close to it until the characters discover that someone on the far side has been bearing the storm’s full force.
The Safe Experiment — A Kaosist demonstrates a technique for stabilizing a hazardous chamber. It succeeds, but the next chamber the characters enter has inherited the danger, placing a trade route at risk.
The Shape Left Behind — After a Kaos surge, a cavern returns to normal except for a human shaped gap in its stone. Several people remember someone standing there, but disagree about whether that person was a friend or an attacker.
The Negotiating Wall — A tunnel wall yields whenever workers ask it politely and hardens when struck. Its cooperation could connect two settlements; one group believes every new opening obliges them to close another.
The Sound of Repairs — Tapping from inside a solid pillar matches the rhythm of local builders at work. When the builders stop, the tapping continues—and hairline cracks elsewhere begin to close.
The Home They Can Carry — A migrating community transports pieces of its old cavern’s floor wherever it settles. The stone keeps them safe during Kalm, but their newest host settlement discovers its own foundations slowly shifting toward the carried pieces.
Notice
These unofficial adventure ideas are offered for anyone who wishes to use or adapt them for their own The World Below campaign.
This is an independent, fan-created collection and is not affiliated with, endorsed, sponsored, or approved by Onyx Path Publishing.
The material is provided freely for personal, noncommercial use, and I receive no money or other compensation from its creation, distribution, or use.
Notice
Currently, these are nothing more than conceived thoughts on exploring the world of The World Below. As I consider them further, they will be expanded with more detail.