Mine
Almost every sapient species digs something they want out of the earth. Dwarves dig for adamantine, shadow elves for mithral and dark iron, grimlocks for copper, and everyone mines for iron, gold, salt, and precious stones. When metal and ore are abundant, mines are busy places, but once the supply of that material dwindles, they become eerie, crumbling labyrinths in the lightless depths of the world.
Tiers. Of all types of dungeons, mines are the most likely to descend deep into the earth; a single mine can encompass multiple tiers. Tier 4 mines are relatively rare, since few miners can sustain their labors among the dangers of the utter depths.
Mine Size. Each 50-foot-square node of a mine contains either a room or passage. A small mine is about 150 feet square (a 3 × 3 grid of nodes); a medium one is 250 feet square (a 5 × 5 grid); and a large one is 350 feet square (a 7 × 7 grid). Most mines are multilevel affairs.
Hazardous Environment. Mines can be dangerous places without a single hostile creature or trap present. Cave-ins, darkness, pockets of poisonous or explosive gas, heavy mining machinery, and yawning mine shafts can spell doom for the unwary. Those with training in Engineering or Nature have advantage on Perception or Investigation checks to spot mine hazards.
Creating a Mine
To generate a new map, roll on the Description table for the initial area and follow its instructions, and then do so again to see what’s past each exit, and so on. If you’re filling a premade map, roll on Inhabitants and Contents for each location.
Mine: Description
| 1 - 2 |
Narrow passage. Roll on Passage Contents and Exits. For passage width, roll 1d6: |
|
| 1 - 2 | 2 1/2 ft. | |
| 3 - 6 | 5 ft. | |
|
3 - 9 |
Passage. 10 feet wide. Roll on Passage Contents and Exits. |
|
| 8 | Wide passage. Roll on Passage Contents and Exits. For passage width, roll 1d4: | |
| 1 | 15 ft. | |
| 2 - 3 | 20 ft. | |
| 4 | 30 ft. | |
| 10 | Wide passage. Roll on Passage Contents and Exits. For passage width, roll 1d4: | |
| 1 - 2 | 15 ft. | |
| 3 - 4 | 20 ft. | |
| 11 - 16 |
Small room. Roll on Room and Chamber Contents and Exits. For room size, roll 1d4: |
|
| 1 |
15 x 15 ft. |
|
| 2 |
15 x 20 ft. |
|
| 3 |
20 x 20 ft. |
|
| 17 - 20 | Large chamber. Roll on Room and Chamber Contents and Exits. For chamber size, roll 1d6: | |
| 1 | 30 x 30 ft. | |
| 2 | 30 x 40 ft. | |
| 3 | 40 x 40 ft. | |
| 4 | 50 x 50 ft. | |
Mine: Passage Contents
|
1 - 10 |
Empty |
|
| 11 - 14 |
Roll on Passage Scenery |
|
| 15 - 18 |
Roll on Escalations |
|
| 19 - 20 |
Roll on Obstacles |
|
Mine: Room and Chamber Contents
Roll 1d20 in small room, 1d20 + 2 in large chamber.
| 1 - 3 |
Empty |
|
| 4 - 8 | Roll on Small Room Scenery or Large Chamber Scenery | |
| 9 - 11 |
Roll on Novelties |
|
| 12 - 14 |
Roll on Obstacles |
|
| 15 - 16 |
Roll on Discoveries |
|
| 17 - 19 |
Roll on Escalations and on Small Room Scenery or Large Chamber Scenery |
|
| 20+ |
Roll on Set Pieces |
|
Mine: Exits
| 1 - 5 |
No Exits |
|
| 6 |
One exit left |
|
| 7 - 8 |
One exit straight |
|
| 9 |
One exit right |
|
| 10 - 11 |
Two exits, left and right |
|
| 12 |
Two exits, left and straight |
|
| 13 |
Two exits, straight and right |
|
| 14 - 15 |
Three exits, left, straight, and right |
|
| 16 - 20 | Ascent or descent. Roll 1d10. Then roll again on this table for other exits. | |
| 1 - 2 |
Sloping tunnel down |
|
| 3 |
Ladder down |
|
| 4 |
Shaft down |
|
| 5 |
Ladder up |
|
| 6 - 10 |
Shaft going 1d4 levels down |
|
Mine: Novelties
| 1 |
Deposit of beautiful (but worthless) crystals that refract light sources around the area in prismatic rainbows |
|
| 2 |
Abandoned giant spider lair choked with webs; the mummified, long-dead bodies of humanoids or other subterranean creatures hang from the ceiling |
|
| 3 |
A wooden shack serves as a makeshift foreman’s office. It’s cozily lit with oil lamps and is a good place to rest |
|
| 4 |
Security checkpoint where guards search workers for contraband such as ore or precious stones |
|
| 5 |
Healthy vein of whatever the mine was built to extract. The area is well lit. Tools, piles of ore sorted by quality, and carts of mined-out dirt and stone fill the area |
|
| 6 |
Elevator beside an underground waterfall. The journey up or down is made to the sound of rushing water, and spray is ever-present |
|
| 7 |
A smaller deposit of some valuable material the mine wasn’t built to extract, marked for later extraction |
|
| 8 |
Workshop filled with broken mine carts and other equipment in need of repair |
|
| 9 |
Pitch dark area filled with resonant crystals that hum eerily and distort speech |
|
| 10 |
Ancient, subterranean room that the mine broke into. The room is empty but features impressive wall carvings |
|
| 11 |
An enormous, supernaturally durable crystal or boulder. Too big to extract, the miners eventually gave up and mined around it, making it the centerpiece of an otherwise empty chamber |
|
| 12 |
Chamber filled with bioluminescent fungus. Pieces of makeshift furniture indicate that someone has been relaxing here |
|
Mine: Obstacles
| 1 |
Lock: Broken, immoble mining elevator. One of the gears has broken teeth, preventing the winch mechanism from working. Key: A replacement gear. |
|
| 2 |
Lock: Shut-down mining machine blocks a passage. Key: A power crystal that allows the characters to move the machine. |
|
| 3 |
Lock: A massive crystal blocks a passageway. Key: A barrel of alchemical solvent that can safely dissolve the crystal |
|
| 4 |
Lock: A passage blocked by a cave-in. Abandoned grimlock explosives have been set but detonate only when exposed to the correct sonic frequency. Key: A modified portable telegraph (see Equipment) that emits the proper frequency and can detonate the explosives, clearing the passage |
|
| 5 |
An apparent cave-in is actually a non-magical optical illusion caused by the uniformity of color and texture of the stone. DC 20 Perception check to spot a tight but navigable path along one edge |
|
| 6 |
Section of the wall embedded with colorful crystals. DC 15 Perception check to notice one of the crystals looks unusually polished for one still in the earth. Pressing the crystal opens a secret door |
|
| 7 |
Close examination (DC 15 Investigation or Perception check) of the wooden walls of this supported tunnel reveals a set of seams. The door opens freely away from the tunnel’s interior, and closes automatically on a spring |
|
| 8 |
An extra button hidden on the underside of a mining machine’s control panel (DC 15 Investigation check to notice) raises a secret door |
|
| 9 - 12 |
Trap based on the dungeon level: level 1–2 caltrops trap or false hoard trap ; 3–4 falling room trap or lidded pit trap ; 5–10 crushing pit trap or false trapdoor trap ; 11–16 crusher trap or hezrou trap; 17–20 deepest collapsing dungeon trap or plummeting room trap |
|
Mine: Discoveries
| 1 - 4 |
Roll 1d4 on the Obstacles table. You find the key listed in that entry. Make a note of the matching lock. The next Obstacle encountered is that lock |
|
| 5 |
A forgotten chunk of some precious substance (gold, mithral, a ruby, etc.) has rolled into a dusty corner. It is worth 500 gp (or 5,000 gp on dungeon level 10 or higher) |
|
| 6 |
Unusually sociable earth elemental embedded in a stone wall. Is actively helpful so long as nobody tries to mine the wall it’s embedded in |
|
| 7 |
Broken-down mining machine. Can be repaired with a DC 18 Engineering check or scrapped for 225 gp worth of parts |
|
| 8 |
Local surveying party and security detail. Friendly toward other humanoids unless they have a specific reason not to be |
|
| 9 |
Abandoned supply room. Contains 2d8 tins of dwarven rations, two pickaxes, an ascender/descender set (see Equipment), and four coils of hempen rope |
|
| 10 - 11 | Ore vein. If mined and smelted over several weeks, the vein produces 100 pounds of metal. The type of metal varies by dungeon level: 1–2 copper, 3–4 silver, 5–10 gold, 11–16 platinum, 17–20 mithril or adamantine | |
| 12 |
Vein of gems. 1d10 gems can be collected without mining. If mined for several weeks, the vein produces a maximum of 50 more gems. The type of gem varies by dungeon level: 1–4 10 gp gem such as quartz, 5–10 100 gp gem such as garnet, 11–16 1,000 gp gem such as sapphire, 17–20 5,000 gp gem such as ruby |
|
Mine: Escalations
50 percent of guards possess a Minor Treasure.
| 1 |
Miners, working on behalf of local overlord (roll or choose from Set Pieces). May be suspicious or hostile |
|
|
Level 3–4: 1 or 2 azers |
||
|
Level 5–10: azer forgemaster or fire elemental with 2 or 3 azers |
||
|
Level 11 - 16: genie (earth) with 2d4 dust mephits |
||
|
Level 17–20: 2 genies (earth) |
||
| 2 |
Guards: on the lookout for thieves |
|
|
Level 3–4: 2d4 deep dwarf soldiers , deep gnome scouts , mountain dwarf soldiers , or scouts |
||
|
Level 5–10: 3 to 5 azers |
||
|
Level 11–16: genie (earth) |
||
|
Level 17–20: master assassin ; 2 assassins and 3 thugs |
||
| 3 |
Raiders or interlopers |
|
|
Level 1–2: 2d4 kobolds |
||
|
Level 3–4: doppelganger or intellect devourer |
||
|
Level 5–10: blackguard or cambion with 2d4 soldiers |
||
|
Level 17–20: rakshasa with 1d4 doppelgangers |
||
| 4 |
Guardians: guarding their lair |
|
|
Level 1–2: 3 or 4 goblins |
||
| Level 3–4: kobold broodguard or thug with 2d4 kobolds ; revilock with 1d4 grimlocks | ||
|
Level 5–10: 2 minotaurs |
||
|
Level 11–16: dread troll with 1 or 2 trolls ; troll hulk |
||
| Level 17–20: adult black dragon lich ; adult shadow dragon ; adult black dragon | ||
| 5 - 6 |
Guardians: lurking |
|
|
Level 1–2: 1d4 giant centipedes , giant fire beetles , or rust monsters |
||
|
Level 3–4: 3 or 4 ghouls , giant spiders , or shadows |
||
|
Level 5–10: 3 or 4 dire centipedes , gricks , or mimics |
||
|
Level 11–16: 2 or 3 earth elementals or xorn |
||
|
Level 17–20: minotaur champion or purple worm |
||
| 7 - 10 |
Roll 1d6 on this table to determine an encounter group. The group is nearby (in the nearest unexplored room) and may be detected by tracks, noises, flickering torchlight, or other signs |
|
Mine: Set Pieces
Set piece encounters usually feature a Treasure Hoard.
| 1 |
Active Mine. Miners have claimed the riches of this mine |
|
|
Level 1–2: kobold broodguard and 2 or 3 kobolds ; 2 azers |
||
|
Level 3–4: azer forgemaster with 2 or 3 azers ; salamander |
||
|
Level 11–16: mountain dwarf lord with 2 mountain dwarf defenders and 2d6 mountain dwarf soldiers ; 2 gladiators with 1d6 + 4 azers |
||
|
Level 17–20: minotaur champion with 2d4 minotaurs ; 2 genies (earth) with 3 or 4 earth elementals |
||
|
Setting: A wide chamber criss-crossed with mine cart tracks and levers to release the carts. |
||
| 2 |
Subterranean Predator’s Lair. The mining operation has attracted an underground predator (or pack of them). Its bone-littered lair must be cleared to make the mines safe again. |
|
|
Level 1–2: dire centipede with 1 or 2 giant centipedes ; 2 ankhegs |
||
|
Level 3–4: ankheg queen with 2d4 ankheg spawn ; bulette |
||
|
Level 5–10: ur-otyugh with 1 or 2 otyughs ; 3 or 4 stone sharks |
||
|
Level 11–16: supermutant rust monster (DDG) with 1 or 2 mutant rust monsters (DDG |
||
|
Level 17–20: 2 or 3 purple worms |
||
|
Setting: A foul, sulfurous stream flows lazily through the middle of a bone-filled den. Characters with a sense of smell must make a DC 10 Constitution saving throw each turn or be poisoned until the start of their next turn |
||
| 3 |
Too Deep, Too Greedily. The mine broke into the resting place of some horrible thing that should not have been disturbed. Darkness permeates and magma flows here. |
|
|
Level 1–2: 2 or 3 ghouls |
||
|
Level 3–4: 2 intellect devourers |
||
|
Level 5–10: forgotten god and 1 or 2 blackguards ; 2 salamanders |
||
|
Level 11–16: draconic horror (DDG) and 3 or 4 gibbering mouthers |
||
|
Level 17–20: balor general or balor and 4 to 6 shadow demons |
||
|
Setting: This dark cavern is lit only by the magma that comprises most of the floor. Irregularly spaced islands of varying sizes rise from the magma. |
||
| 4 |
Unquiet Earth. The earth itself rebels against the miners’ intrusions |
|
| Level 1–2: 2 to 4 dust mephits or magmins | ||
| Level 3–4: earth elemental and 1d4 dust mephits | ||
| Level 5–10: genie (earth) and 1 or 2 earth elementals | ||
| Level 11–16: giant earth elemental and stone guardian ; 2 or 3 devas | ||
| Level 17–20: sand worm and 1 to 3 stone guardians ; 2 planetars | ||
| Setting: A jumble of geological permutations creates a confusing battlefield for combatants, with massive crystals and boulders sitting side-by-side with pools of quicksand | ||
Mine: Minor Treasure
| 1 |
Several well-labeled vials of an explosive chemical (treat as necklace of fireballs ) |
|
| 2 - 8 | Precious ore, gems, metal bars, or a single adamantine drill bit worth an amount appropriate to the tier (tier 0: 10 gp, tier 1: 100 gp, tier 2: 1,000 gp, tier 3: 10,000 gp, tier 4: 100,000 gp) | |
| 9 |
1d6 vials. Roll 1d6: 1–3 potions of healing , 5–6 potions of hill giant strength |
|
| 10 |
+1 war pick (or, on dungeon level 10 or deeper, prospector’s pick) |
|
| 11 |
elemental gem containing an earth elemental |
|
| 12 |
A lockbox containing the miners’ wages (tier 0: 100 gp, tier 1: 250 gp, tier 2: 2,500 gp, tier 3: 25,000 gp, tier 4: 250,000 gp |
|
Mine: Treasure Hoards
| Dungeon Level 1–2 |
Valuables: 1d4 × 100 gp worth of metal ore or uncut gems Magic (30 percent chance): bag of holding or circlet of blasting |
|
| Dungeon Level 3–4 |
Valuables: 2d4 × 100 gp worth of bars of precious metal or gems Magic (40 percent chance): brazier of commanding fire elementals or gem of brightness |
|
| Dungeon Level 5–10 |
Valuables: 1d6 × 1,000 gp worth of bars of precious metal or gems Magic (50 percent chance): wand of enemy detection or winged boots |
|
| Dungeon Level 11–16 |
Valuables: 1d4 × 10,000 gp worth of gems Magic (60 percent chance): ring of telekinesis or stone of controlling earth elementals |
|
| Dungeon Level 17–20 |
Valuables: 1d4 × 100,000 gp worth of gold and platinum coins, mithral and adamantium bars, or gems Magic (70 percent chance): ring of elemental command or vorpal blade |
|
Mine: Passage Scenery
| 1 |
Mined-out node. Whatever the mine was built to extract has been exhausted |
|
| 2 |
Connecting room or passage. Exists primarily as a waystation between other locations. Signs mark the exits |
|
| 3 | Heaps of dirt and low-value ore waiting to be carted out of the mine | |
| 4 |
Broken mining cart sitting next to a track |
|
| 5 |
Collapsed tunnel leading to an inactive area of the mine |
|
| 6 |
Graffiti scratched or chalked across the walls |
|
| 7 |
Roosting bats. The ground is carpeted in guano |
|
| 8 |
Rivulets of water run down the walls. The water is safe to drink but gathering more than a few drops would take hours |
|
| 9 |
A miner’s pick still buried in the wall |
|
| 10 |
A stack of lumber used to shore up unstable areas |
|
Mine: Small Room Scenery
| 1 |
Worker’s ready room. Pick axes and mining helmets are lined up neatly on shelves along the walls |
|
| 2 |
Worker’s room. As above, but the room is a mess. Personal effects are mixed among the improperly stored equipment |
|
| 3 |
Supply room. Spare pick axes, lanterns, and other common mining gear is stored here |
|
| 4 |
Break area. Tables and chairs sit empty |
|
| 5 |
Decommissioned security checkpoint |
|
| 6 |
Latrines |
|
| 7 |
Supply room. Barrels of nails, stacks of timber, and boxes of rations are neatly stacked and cataloged |
|
| 8 |
Deposit of worthless, mundane crystals |
|
| 9 |
Section of natural cave |
|
| 10 |
Assembly station for mining supports. Cluttered with timber and sawhorses |
|
| 11 |
Area is damp and drippy. Stalactites and stalagmites cover the ceiling and floor, respectivel |
|
| 12 |
Ancient, dried-out bones of some underground creature huddled in a corner |
|
Mine: Large Chamber Scenery
| 1- 2 |
Underground lake in a cavernous natural cave |
|
| 3 |
Mess hall. Rows of dining tables sit beneath lanterns hanging from the ceiling |
|
| 4 |
Kitchen. Stoves and cooking pots sizzle and bubble. Crates of edible fungus abound |
|
| 5 |
Heavy mining machines are parked here, awaiting further usage or repairs |
|
| 6 |
Ore processing machines. Grinders, crushers, and conveyor belts crisscross this noisy area. Perception checks based on hearing are made at disadvantage |
|
| 7 |
Staging area for mine expansion. Dozens of pre-built supports of varying sizes are stacked in piles around the room |
|
| 8 |
Processing. Inbound supplies are received, sorted, and sent off to other areas of the mine. Workbenches and sorting tables sit beside piles of crates |
|
| 9 |
Central switching station for an elaborate minecart network. Several mine carts (either full or empty) are parked here, ready to be dispatched into other parts of the mine |
|
| 10 |
Slain purple worm partially broken down for food and removal from the mine. Resembles a whaling operation |
|
| 11 |
Summoning circle |
|
| 12 |
Docks line the banks of an underground river or lake |
|