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Caverns

Caverns

Under the earth lie twisting passages, vast caverns, and underground rivers, all cloaked in endless darkness. The environment itself can be just as dangerous as its inhabitants.

This generator lets you map a cave system. For Underland travel, see Underland Realm in Trials & Treasures.

Tiers. Tier 0 and 1 adventurers measure themselves against natural caves and caverns. Tier 2 and 3 adventurers delve deeper, into Underland itself.

Cavern Size. Each 70-foot-square node of a cavern contains either a cavern or a section of passage. A small cavern system is about 210 feet square (a 3 × 3 grid of nodes); a medium temple is 350 feet square (a 5 × 5 grid); and a large one is 490 feet square (a 7 × 7 grid). Underland is a vast megadungeon in which a single cavern system can extend for miles.

Treacherous Terrain. Naturally occurring caves are often slippery and riddled with pits and stony outcroppings. Whenever a creature uses the Dash action, it must make a DC 12 Dexterity saving throw at the end of its turn, falling prone on a failure.

Creating a Cavern

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.

Cavern: Description

 

1 - 2

Narrow passage. Roll on Passage Contents and Exits. At its narrowest, the passage is 1d6 + 1 feet wide.

3 - 6

Passage. Roll on Passage Contents and Exits. The passage is about 10 feet wide.

7 - 8

Wide passage. Roll on Passage Contents and Exits. At its narrowest, the passage is 1d20 + 10 feet wide.

9 - 14 Small room. Roll on Room and Chamber Contents and Exits. For room size, roll 1d4:
1

10 x 10 ft.

2

15 x 15 ft.

3

15 x 20 ft.

4

20 x 20 ft.

5 20 x 20 ft.
6 20 x 30 ft.
15 - 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

40 x 50 ft.

5 50 x 50 ft.
6 50 x 60 ft.
7 60 x 60 ft.
8 70 x 70 ft.

 

Cavern: Passage Contents

1 - 10

Empty

11 - 14

Roll on Passage Scenery

15 - 18

Roll on Escalations

19 - 20

Roll on Obstacles

 

Cavern: Cavern Contents

Roll 1d20 in small cavern, 1d20+2 in large cavern

1 - 3

Empty

4 - 8 Roll on Small or Large Cavern Scenery
9 - 11

Roll on Novelties

12 - 14

Roll on Obstacles

15 - 16

Roll on Discoveries

17 - 19

Roll on Escalations and on Small or Large Cavern Scenery

20+

Roll on Set Pieces

 

Cavern: Exits

If the die roll is odd, a room's exits are blocked by doors. Otherwise, they are open

1 - 3

No Exits

4 - 5

One exit left

6 - 7

One exit straight

8 - 9

One exit right

10 - 11

Two exits, left and right

12 - 13

Two exits, left and straight

14 - 15

Two exits, straight and right

16 - 18

Three exits, left, straight, and right

19 - 20 Ascent or descent. Roll 1d8. Then roll again on this table for other exits.
1 - 2

Sloping passage down

3

Vertical climb down

4

Vertical passage descending 1d4 levels

5

Vertical climb up

6

Stone spiral staircase up

7

Trapdoor up

8

Stairs going 1d4 levels up and 1d4 levels down

 

Cavern: Novelties

1

Crystals or mushrooms that cast dim light cover the walls

2

Stalactites and stalagmites made of transparent or invisible stone fill the area

3

Rocks are coated with a reflective metal or algae that turns surfaces into distorted mirrors

4

Natural, fluted stone pillars support high ceilings, giving the area the appearance of a temple

5

An island sits in the middle of a lake of magma, silvery water, or ice

6

A grove of trees or giant mushrooms

7

Cavern spanned by multiple, naturally occurring stone bridges

8

Tiers of towers, gates, doors, statues, and stairs are carved into the sloping rock walls

9

A shield-sized crystal embedded in the ceiling sheds bright light throughout the area

10

A chasm spanned by a narrow bridge or flat-topped pillars like stepping stones

 

Cavern: Obstacles

1

Lock: Narrow passage, 3 inches wide, carved with the words “Gates of Gathor.”

Key: A written command phrase, “Gates of Gathor, open the door,” which causes the passage to grind open to a width of 10 feet

2

Lock: Passage choked with petrified fungus.

Key: A nest of mouselike fungus creatures that eat petrified fungus

3 - 4

Tight squeeze: at its narrowest, the passage is 1d12 + 10 inches wide

5 - 6

Collapsed ceiling: An exit is blocked by 1d6 + 4 feet of rubble. The rubble can be excavated as if it were dirt

7 - 8

Chasm: The chasm is 1d20 + 10 feet wide and more than twice as deep. At the bottom may be magma, an underground river, or another dungeon level

9 - 10

Underwater area: The exit to an adjoining area is through a flooded passage that is 1d6 × 10 feet long. The adjoining area may be partially or fully underwater

11

Fast-flowing underground river: The river is 1d10 + 10 feet wide. A creature that starts its turn in the river moves 60 feet downstream. The river may lead to rapids

12

Magma: A 10- or 15-foot-wide stream of magma blocks the way

13 - 20 Trap or other exploration challenge (see Trials & Treasures) based on the dungeon level:
level 1–2 wind tunnel or poorly repaired tunnel (T&T);
3–4 green slime hatch or hidden pit trap;
5–10 flammable gas trap or lethal outgassing (T&T); collapsing dungeon or sinkhole (T&T);
17–20 obsidian vine trap or perilous cliff path (T&T)

 

Cavern: Discoveries

1

The key listed in entry 1 of the Obstacles table

2

The key listed in entry 2 of the Obstacles table

3

Pool of water containing 1d4 + 4 large, edible fish

4

Pool of glowing water fed by a dripping stalactite. Drinkers gain blindsight out to a range of 60 feet for 24 hours. The water ceases to glow and loses its potency 1 minute after being removed from the pool

5 - 6

1d6 fragrant mushrooms. If eaten, roll 1d4 to determine their effect. The mushrooms lose their potency 1 hour after being harvested

1 For 5 days, the creature gains the plant type, gains blindsight to a distance of 10 feet, and doesn’t need to eat
2 The creature gains 3 temporary hit points per character level. While it has these temporary hit points, it has advantage on Perception checks that rely on smell
3 The creature gains telepathy out to a distance of 120 feet until it finishes a long rest
4 The creature gains the benefit of the detect magic spell until it finishes a long rest
7

Cache of supplies containing useful equipment and an incomplete map

8

Corpse; among its possessions is a journal listing either the name of a powerful dungeon creature (see Set Pieces) or one of the treasures it guards (see Treasure Hoards)

9

Lone creature from a guard patrol (1 or 2 on Escalations table), not particularly loyal and willing to talk

10

Guard patrol (1 or 2 on Escalations table) escorting a prisoner; the prisoner offers aid or information to its rescuers

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 mithral 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

 

Cavern: Escalations

50 percent of guards possess a Minor Treasure.

1

Guards: may attack intruders who don’t immediately show peaceful intent

Level 1–2: 1d4 goblins

Level 3–4: revilock with 1d4 grimlock technicals ; 2 ogres

Level 5–10: dread troll , ogre mage , or fire giant

Level 11–16: minotaur champion ; 2 fire giants

Level 17–20: stone giant with 2 hill giants

2

Guards: guarding a particular location

Level 1–2: 1 or 2 troglodytes

Level 3–4: kobold broodguard with 2d6 kobolds ; 3 or 4 bugbears

Level 5–10: shadow elf champion warrior with 2d8 shadow elf warriors ; 1d4 + 5 azers

Level 11–16: drider , shadow elf high priest , or shadow elf mage with 2 shadow elf champion warriors ; 2 driders

Level 17–20: 2 cyclops myrmidons or cloud giants

3

Guards: hunting

Level 1–2: 1d4 swarms of bats or swarms of rats

Level 3–4: black pudding

Level 5–10: bulette or slime mold

Level 11–16: giant grick with 3 or 4 gricks ; 2 purple worms

Level 17–20: mutant rust monster and supermutant rust monster

4

Guardians: in lair

Level 1–2: 1d4 giant bats or giant centipedes

Level 3–4: 1 or 2 mimics or wallflowers

Level 5–10: 2 or 3 euphoria jellies or flash cubes

Level 11–16: roper with 1d6 + 6 piercers

Level 17–20: 2 cloakers

5

Guardians: wandering

Level 1–2: 1 or 2 gray oozes , rust monsters or violet fungi

Level 3–4: 1 or 2 cave bears or dire centipedes

Level 5–10: 2 stone sharks

Level 11–16: purple worm

Level 17–20: murmuring worm with otyugh ; 2 cloakers

6

Denizens: warring against, or hiding from, local overlord (roll or choose from Set Pieces)

Level 1–2: 1d4 flumphs or kobolds

Level 3–4: priest with 1d4 deep dwarf soldiers , deep gnome scouts , or scouts

Level 5–10: 1 or 2 xorn

Level 11–16: 2 champion warriors with 2d10 warriors ; 2 gladiators with mage

Level 17–20: 2 fomorians

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

 

Cavern: Set Pieces

Set piece encounters usually feature a Treasure Hoard.

1 - 2

Hail the Conquering Villains. A raiding party has captured the residents of a rival settlement. They mean to exile, sacrifice, or even pit the captives against each other in gladiatorial games—and they’ll do the same to meddling adventurers.

Level 1–2: kobold broodguard with 1d4 + 4 kobolds ; bugbear with 1d4 hobgoblins

Level 3–4: bandit captain with dire wolf and 1d8 + 8 bandits

Level 5–10: shadow elf champion warrior with 20 shadow elf warriors and either shadow elf mage or high priest ; 3 salamanders with 4 azers

Level 11–16: minotaur champion with gorgon and 3 minotaurs ; storm giant with 2 frost giants and 2 ogres

Level 17–20: ancient sapphire dragon with 4 kobold broodguards and 20 kobolds ; ancient red dragon with 2 half-red dragon veterans and 20 kobolds

Setting: The chamber contains cages of prisoners. Releasing all the prisoners distracts the enemy combatants with the lowest CR, removing them from the battle.

3 - 4

Exile. A powerful champion was exiled from its kind. Without allies, it considers every creature to be its enemy—or its prey. It might grant a few moments of life to creatures that offer it a way to hurt the creatures that exiled it.

Level 1–2: cave ogre ; ogre

Level 3–4: hobgoblin warlord ; troll

Level 5–10: deva

Level 11–16: troll king

Level 17–20: empyrean ; ]]King Fomor]]

Setting: In other areas of the dungeon are groups of the creatures that exiled the creature (for instance, ogres in a level 1 or 2 dungeon). These creatures might join adventurers against the exile, or vice versa.

5 - 6

False Adventuring Party. A group appears to be humanoid adventurers. In fact, they’re monsters that prey on the caverns’ humanoid denizens. If the characters talk to other cavern inhabitants, they may hear rumors of friendly seeming creatures who suddenly change form and attack.

Level 1–2: doppelganger

Level 3–4: 2 or 3 doppelgangers

Level 5–10: 2 assassins or ogre mages

Level 11–16: 2 rakshasas

Level 17–20: vampire assassin , vampire mage , and vampire warrior ; 3 rakshasas

Setting: The cave is filled with ill-gotten treasure—some of which is not what it seems. Depending on dungeon level, the treasure may be guarded by:

Level 1–2: false hoard trap
Level 3–4: mimic
Level 5–10: ghost trap
Level 11–16: nalfeshnee trap
Level 17–20: hidden cannon trap
7

A cave-in behind the party seals off the cavern complex’s entrance. There are other exits from the complex, but they lead into miles of winding, deserted Underland tunnels. On each day of travel through these tunnels, the party’s navigator must make a Nature or Survival check to find their way. Three successes, or one critical success, allows the party to escape the maze.

8 The way is blocked by a settlement of deep dwarves, shadow elves, grimlocks, troglodytes, mycelials, or other underground dwellers. There are too many to fight, although the adventurers might be able to defeat or elude patrols. The easiest way through the settlement is to negotiate safe passage with its leaders.

 

Cavern: Minor Treasure

 

1

2d6 edible mushrooms

2

Glowing lichen casts bright light for 20 feet and dim light for an additional 20 feet. The lichen glows for 1 month after it’s harvested

3 - 4

Cultural equipment, such as deep dwarf stone of resolve

5 - 6

Gems 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)

7

1d6 vials. Roll 1d6: 3–4 potions of healing , 5–6 potions of greater healing

8

Mushroom-based alcoholic beverage that causes drinkers to be poisoned for 1 hour. While poisoned, drinkers can cast clairvoyance at will

9

Map to a valuable mineral deposit (see Discoveries 11 and 12)

10

Cache of 1d6 magical shadow elf weapons made of dark iron: they’re +1 weapons but they crumble in sunlight. On dungeon level 11 or higher, they’re +2 weapons instead

 

Cavern: Treasure Hoards

Dungeon Level 1–2

Valuables: 1d4 × 100 gp worth of silver and gold coins or gems

Magic (30 percent chance): gloves of swimming and climbing or vicious weapon

Dungeon Level 3–4

Valuables: 2d4 × 100 gp worth of silver and gold coins or 1d6 masterwork weapons worth 150 gp each

Magic (40 percent chance): ring of resistance or wand of enemy detection

Dungeon Level 5–10

Valuables: 1d6 × 1,000 gp worth of gold coins, gems, or metal ore

Magic (50 percent chance): ring of animal influence or wand of web

Dungeon Level 11–16

Valuables: 1d4 × 10,000 gp worth of gold and platinum coins or jewelry

Magic (60 percent chance): ring of the ram or sword of sharpness

Dungeon Level 17–20

Valuables: 1d4 × 100,000 gp worth of electrum, gold, and platinum coins and jewelry

Magic (70 percent chance): Harvest or ring of invisibility

 

Cavern: Passage Scenery

1 - 2

The passage twists and turns: visibility is reduced to 10 feet

3

The passage climbs and drops; it is difficult terrain

4

The passage has a three-foot ceiling; Medium creatures must crawl

5

The passage is a fissure with a ceiling hundreds of feet high

6

The passage’s walls are wet

7

The passage’s walls are covered with stone spikes. A creature pushed into a wall takes 3 (1d6) piercing damage

8

The passage is crossed by a shallow, 10-footwide stream that emerges from and flows into narrow flooded tunnels

9

The passage is round and perfectly smooth. DC 13 Nature check: it may have been bored by a purple worm

10 The passage is a round tube with a deep fissure stretching its entire length. A stream runs at the bottom of the fissure

 

Cavern: Small Cavern Scenery

 

1

The floor and ceiling are festooned with stalagmites and stalactites. The area is difficult terrain

2

Stalagmites, stalactites, and columns make most of the cavern difficult terrain , though there is an open space in the middle

3

Delicate sheets of stone hang from the ceiling like drapery

4

Translucent crystals cover the walls and ceiling. Crystal columns connect the roof and floor

5

Surfaces are covered in a delicate lattice of white crystals that resemble frost or snow

6

Lovely stone formations that resemble lilies grow from the floor

7

Walls, stalactites, and stalagmites are fluted with thin, vertical channels

8

Crystalline, hollow stone tubes, an inch or two thick, hang from the ceiling

9

Stalactites of vivid blue, green, and yellow hang from the ceiling

10

The cave features a bubbling, geothermal pool. Once per day, a creature can bathe in the pool during a short rest to recover 1 level of fatigue

11

A waterfall spills from a hole in the wall or ceiling to feed a subterranean lagoon

12

A perfectly still pool is disturbed every few minutes by a drop of water from a stalactite

13 The floor is submerged in 1d4 feet of water
14 The cavern features a pool with a stalagmite-covered island in the middle
15 The cavern features an open pit filled with a pool at the bottom. There’s a 50 percent chance that the pool contains a Minor Treasure
16 Vertical shafts in the ceiling or floor lead to the room’s exits
17 Half the cavern is a sunken area, 10 feet lower than the rest
18 The cavern is composed of two chambers connected by a narrow opening
19 A column 5 to 15 feet in diameter dominates the center of the cavern
20 The cavern contains an abandoned camp, including tents, firepit, and old refuse. There is a 50 percent chance that a Minor Treasure is found among the detritus

 

Cavern: Large Cavern Scenery

 

1

The floor and ceiling are festooned with stalagmites and stalactites. The area is difficult terrain

2

Purple worm skeleton

3

Sharp, translucent crystals cover the walls and ceiling. The floor is difficult terrain . Foot-wide crystal bridges crisscross the cavern

4

Lovely stone formations that resemble lilies grow from the floor

5

The cavern features a wide, still lake. Stone pedestals serve as stepping stones

6

Waterfalls spill from the wall or ceiling, feeding a lake or river

7

Stone pillars rise from a lake to support the cavern’s high, arched ceiling

8

A river meanders down the center of the cavern before draining into a vertical shaft

9

A steaming lake surrounds an island. A creature that begins its turn in the lake or enters it for the first time on a turn takes 5 (1d10) fire damage

10

Craggy islands dot the surface of a vast, underground lake

11

The room’s exits can be reached only by climbing the cavern walls

12

The cavern is composed of two chambers connected by a narrow opening

13 Magma cascades through a hole in the ceiling, feeding a meandering magma river
14 The ground is hot to the touch, burning unprotected feet. A weight of 500 pounds placed on a particular 10-foot-square area of floor, or dealing 10 bludgeoning damage to an area of floor, causes it to crumble into a magma chamber below
15 The cavern is ringed by several tiers of naturally-occurring balconies
16 The wreck of a subterranean sea vessel
17 Natural stone bridges crisscross a lake of magma or water
18 The cavern stretches hundreds of feet above or below the entrance. Exits may connect to other dungeon levels
19 A forest of giant mushrooms, each dozens of feet tall, fills the cavern. The area is difficult terrain , and visibility is limited to 10 feet
20 A lake of glowing white or pitch-black water fills the cavern. Water taken from this lake functions like a light or darkness spell for 24 hours

Dungeon Vehicles

Dungeon Vehicles

Underland boasts many of the same vehicles that ply surface roads and seas. Shadow elf couriers use giant spider-drawn chariots, and galleys sail the Midnight Sea. Safe from inclement weather, airships fly through mammoth caverns and miles-long ravines.

A few vehicles are unique to the Underland. Aboleth-built submarines ferry treasure and thralls to underwater cities. Armed with torpedoes, aboleth submarines fight a never ending war against the fleets of sunless mariners.

 

Table: Underwater Vehicles

Vehicle

Size

AC

Hit Points

Speed

Crew

Cost

Supply

Special

Submarine

Gargantuan 16 600 60 feet/6 mph

12

50,000 gp 600 Submersible, armed (torpedo x4)

 

Submersible. Submersible vehicles seal themselves and travel safely below the surface of the water, providing sufficient air and pressure protection to keep their crew safe from the hazards of undersea travel. They can move in three dimensions underwater or travel along the water’s surface.

 

Table: Siege Weaponry

 

Weapon Size Cost AC Hit Points Range Target Damage
Torpedo Large 1,500 15 100 500/2,000 ft.* One 8d10 bludgeoning

* Torpedoes can fire only through water. They cannot be launched above the surface.

 

 

Bastions

Bastions

From underground lairs to mighty castles, bastions are well-defended homes inhabited by creatures worried about attacks from the outside world. A bastion usually contains barracks, food preparation and storage areas, and a throne room or other command center.

Tiers. Tier 0 and 1 bastions are usually bandit lairs. Tier 2 and higher bastions are frequently the mighty castles of rulers and conquerors.

Bastion Size. Each 50-foot-square node of a bastion contains either a room or passage. A small bastion 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).

Alert. After each of the first 3 encounters, one additional creature is added to each future encounter. The extra creature is of the encounter’s lowest-CR type.

Creating a Bastion

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.

Bastion: Description

1

Narrow passage. Roll on Passage Conetns and Exist. For passage width, roll 1d6:

1 - 2 2 1/2 ft.
3 - 6 5 ft.

2 - 7

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.

9 - 14 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.

4

20 x 30 ft.

15 - 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.

 

Bastion: Passage Contents

1 - 10

Empty

11 - 14

Roll on Passage Scenery

15 - 18

Roll on Escalations

19 - 20

Roll on Obstacles

 

Bastion: 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

 

Bastion: Exits

If the die roll is odd, a room's exits are blocked by doors. Otherwise, they are open

1 - 3

No Exits

4 - 5

One exit left

6 - 7

One exit straight

8 - 9

One exit right

10 - 11

Two exits, left and right

12 - 13

Two exits, left and straight

14 - 15

Two exits, straight and right

16 - 18

Three exits, left, straight, and right

19 - 20

Stairs. Roll 1d8 to determine stair type. Then roll again on this table for other exits

1 - 2

Stone stairs down

3

Stone spiral staircase down

4

Trapdoor down (50 percent chance concealed under rug or furniture)

5

Ladder up or down (50 percent chance each)

6

Stone spiral staircase up

7

Trapdoor up

8

Stairs going 1d4 levels up and 1d4 levels down

 

Bastion: Novelties

1

Cannon; nearby are cannonballs and barrels of powder

2

Magic wall map of the area around the stronghold, identifying the locations of any non-hidden creatures

3

Arched bridge leading to an iron door halfway up a wall

4

Immense, monstrous statues on either side of a door

5

Drawbridge made of wall of force

6

Miniature model of this fortress, populated by tiny illusions of its inhabitants

7

Beast heads mounted on the wall; although bodiless, they are alive and can bite

8

A marble table around which sit the spirits of dead warriors re-enacting an ancient feast

9

Hundreds of life-sized, sculpted warriors standing in battle array

10

A war banner 20 or 30 feet on a side

11

Portrait gallery; each portrait enchanted with a permanent magic mouth

12

Narrow shafts that carry sound; perfect for eavesdropping or communicating between distant chambers

 

Bastion: Obstacles

1

Lock: A door that demands today’s password.

Key: A list of passwords, each next to a day of the week

2

Lock: A door bearing a family crest.

Key: A key bearing the crest

3

Lock: A door with an indentation in the shape of a gauntlet.

Key: A gold-plated gauntlet

4

Lock: A door with an indentation in the shape of a gauntlet.

Key: A gold-plated gauntlet

5

Locked wardrobe. Inside the wardrobe is a concealed door

6

Arcane locked door bearing a bronze face that changes its facial expression every minute. The door is unlocked to any creature imitating the expression

7

A bricked-up door, requiring a DC 16 Strength check to smash. Nearby is a secret door in a fireplace that bypasses the door

8

Door concealed behind a full-length mirror leaning against the wall. The edges of the mirror are covered with fingerprints as if it is often moved

9

Door on a balcony high up the wall. The ladder to the balcony is missing

10

Mounted bronze deer head, dull except for one shiny antler. Turning the antler opens a secret door

11

Throne room; pressing a button on the throne’s right armrest opens a hidden pit trap , pressing the left button opens a secret door

12

Only the (harmless) ghost of the bastion’s former seneschal knows the location of a secret door

13 - 20

Trap based on the dungeon level:

1 - 2

crossbow trap or lock trap

3 - 4

falling axe trap or locking-lidded pit trap

5 - 10

ballista trap or spiked pit trap

11 - 16

crushing room trap or green dragon poison gas trap

17 - 20

cannon trap or supercharged metal cube

 

Bastion: 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

Lone creature from a guard patrol (roll 1d4 on Escalations table), not particularly loyal and willing to talk

6

Guard patrol (roll 1d4 on Escalations table), dissatisfied with their commander and willing to turn a blind eye or even aid intruders

7

Guard patrol (roll 1d4 on Escalations table), exchanging revealing gossip about their commander and not paying attention to surroundings

8

Messenger with urgent news

9

An armory containing ranged weapons, ammunition, and ballistas. A dozen +1 arrows. 50 percent chance of a javelin of lightning or other Minor Treasure

10

A richly furnished bed chamber containing a four-poster bed, a desk, wardrobes, and treasure chests containing a Treasure Hoard

11

A chest containing officers’ armor and uniforms

12

Treasure vault filled with several splintered chests and one locked iron chest containing a Treasure Hoard

 

Bastion Escalations

50 percent of guards possess a Minor Treasure.

1

Guards: on patrol. If they meet creatures not dressed as guards, they sound the alarm and attack

Level 1–2: noble with 1d4 guards

Level 3–4: 2d4 hobgoblins or soldiers

Level 5–10: knight with acolyte and 2d4 soldiers

Level 11–16: blackguard or holy knight with priest and soldier squad ; 2 gladiators with mage

Level 17–20: ascetic grandmaster or knight captain with soldier squad ; archmage with gladiator and 1d6 thugs

2

Guards: off duty but alert

Level 1–2: 2d4 bandits or warriors

Level 3–4: veteran with 2d4 bandits

Level 5–10: duelist with apprentice mage and 1d4 thugs ; 2 or 3 veterans

Level 11–16: gladiator or high priest with 2 or 3 veterans

Level 17–20: assassin or mage with 2d6 cutthroats or spies

3

Guards: guarding a particular location

Level 1–2: 1d8 guards or kobolds

Level 3–4: 1 or 2 bugbears with 2d4 goblins

Level 5–10: ogre or warhordling orc eye with 1d4 orc urks or thugs

Level 11–16: frost giant with 1 or 2 ettins

Level 17–20: marilith or minotaur champion with 2d6 guards or warriors

4

Inhabitants: planning to ambush a different inhabitant, perhaps a group of guards or the local overlord (roll or choose from Set Pieces). They may be disloyal, ambitious, or looking to exact revenge for a past betrayal

Level 1–2: apprentice mage or thug with 1d4 bandits

Level 3–4: priest with 1d4 guards or soldiers

Level 5–10: cambion with 1d4 thugs

Level 11–16: vampire mage , vampire , or wraith lord

Level 17–20: archpriest with skeleton horde or water elemental

5

Guardians: guarding a location

Level 1–2: animated armor

Level 3–4: rug of smothering with gargoyle

Level 5–10: 2 or 3 mummies or walking statues

Level 11–16: chain devil with 1 or 2 mummies or walking statues

Level 17–20: 2 chain devils , clay guardians , or giant elementals

6

Guardians: following instructions

Level 1–2: gargoyle or hound guardian

Level 3–4: 1 or 2 bolt-throwers or ogre zombies

Level 5–10: 1 or 2 clockwork sentinels or fire elementals

Level 11–16: iron guardian or nalfeshnee

Level 17–20: 2 crushers[[, [[glabrezus , or stone guardians

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

 

Bastion: Set Pieces

Set piece encounters usually feature a Treasure Hoard.

1 - 2

Raiders’ Lair. The area is home to a wellguarded settlement or camp. The bastion’s denizens may raid nearby areas for food and treasure or merely defend themselves against outside threats.

Level 1–2: goblin boss with goblin warlock and 3 or 4 goblins ; 4 or 5 hobgoblins

Level 3–4: bandit captain with 2 thugs and 2d6 bandits

Level 5–10: gladiator or warhordling war chief with 1d6 + 1 berserkers

Level 11–16: hill giant chief with cave bear and 1d4 + 1 hill giants ; 3 frost giants

Level 17–20: troll hulk with 4 or 5 trolls

Setting: The room features a large drum, gong, bugle, or other loud instrument. If combat starts, a creature tries to sound the alarm, summoning a guard patrol (choose one from Escalations).

3 - 4

Army Headquarters. The inhabitants are part of an organized military, either defending a fortification or prison or preparing to conquer the local countryside.

Level 1–2: scout or soldier with 2d4 guards

Level 3–4: hobgoblin captain , knight , or veteran with 1d4 + 4 hobgoblins or soldiers

Level 5–10: blackguard , cambion , or holy knight with priest and 1d4 knights

Level 11–16: archmage or knight captain with mage and 1d4 knights

Level 17–20: blademaster with 3 gladiators or holy knights ; archmage with 5 gladiators

Setting: Ladders lead to balconies or ledges. If the alarm has been sounded, creatures with ranged attacks are up high.

5 - 6

War Caster. A spellcaster commands an army. Their eyes are fixed on conquest.

Level 1–2: priest with 1d8 guards

Level 3–4: minstrel or priest with 1d6 thugs

Level 5–10: mage or necromancer with soldier squad or wraith

Level 11–16: archmage with 3 or 4 elementals

Level 17–20: archpriest or blademaster with 3 or 4 champion warriors or gladiators

Setting: This lair features an exit concealed behind a throne, tapestry, or other room feature. Besides their other spells, the primary spellcaster has prepared either expeditious retreat or sanctuary to escape.

7 - 8

Prison cells contain friendly creatures that could aid the adventurers if freed.

 

Bastion: Minor Treasure

 

1

+1 weapon that glows like a torch when wielded

2

Magically animated playing cards; the face cards trash talk each other during games

3

Bundle of 12 pieces of +1 ammunition that ignite when fired, dealing an additional 1d6 fire damage

4

Spell scroll containing a spell appropriate to the area’s tier (tier 0: cantrip or level 1 spell, tier 1: level 2–3 spell, tier 2: level 4–5 spell, tier 3: level 6–7, tier 4: level 8–9)

5 - 6

Bag of coins or cache of rare wine 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)

7

1d6 vials. Roll 1d6: 1–3 potions of healing , 5–6 potions of greater healing

8

Cup, ewer, or drinking horn of precious metal, worth an amount appropriate to the tier (tier 0: 25 gp, tier 1: 75 gp, tier 2: 750 gp, tier 3: 2,500 gp, tier 4: 25,000 gp)

9

A dozen masterwork weapons or shields, worth 150 gp each

10

Signed order from the bastion’s commander allowing free entry

 

Bastion: Treasure Hoards

Dungeon Level 1–2

Valuables: 1d4 × 100 gp worth of silver and gold coins

Magic (30 percent chance): +1 weapon or gauntlets of ogre power

Dungeon Level 3–4

Valuables: 2d4 × 100 gp worth of gold coins or trade goods

Magic (40 percent chance): armor of resistance or berserker axe

Dungeon Level 5–10

Valuables: 1d6 × 1,000 gp worth of gold coins or gems

Magic (50 percent chance): +2 weapon or bracers of defense

Dungeon Level 11–16

Valuables: 1d4 × 10,000 gp worth of platinum coins or gems

Magic (60 percent chance): +2 shield or rod of rulership

Dungeon Level 17–20

Valuables: 1d4 × 100,000 gp worth of gold coins, gems, or jewelry

Magic (70 percent chance): +2 armor or belt of storm giant strength

 

Bastion: Passage Scenery

1

Dusty suit of armor or mounted monster head

2

Weapons crossed on the wall

3

Racks or barrels hold spare weapons and ammunition

4

Three camp stools gathered around a small table

5

Tapestries line the walls

6

Brackets hold unlit torches

7

Pushed into a corner is an archery target bristling with arrows

8

A shrine or statue of a war god

 

Bastion: Small Room Scenery

 

1

Tables bearing candles and decks of cards are scattered around the room

2

Armory containing spears, shortswords, crossbows, and light armor. 50 percent chance of holy water, acid, alchemist’s fire, or caltrops

3

Elegant dining room for six or so guests. Table settings are worth 200 gp. Two bottles of vintage wine, worth 50 gp each, stand on a side table

4

Barracks with neatly made beds, weapon racks, and a table heaped with armor, game boards, and personal possessions

5

Comfortable barracks used by high-level guardians. On the walls are weapon racks, armor stands, paintings, and a full-length mirror

6

A shrine on which are laid fresh offerings

7

A guardroom containing benches and tables, cards and game boards, wine jugs and plates of half-eaten food

8

A small kitchen containing a fireplace, wine ready to mull, cheeses, and barrels of biscuits

9

A pantry stocked with flour and beans and hung with herbs

10

A library containing works of strategy and history, as well as atlases and sheafs of papers

11

A latrine: the smelly privy may lead down to a lower level

12

A locked room containing spy holes that let you see what's happening in adjoining areas

 

Bastion: Large Chamber Scenery

1

A comfortable lounge with couches, overstuffed chairs, bookshelves, and a wine bar

2

An armory containing plate armor, chain mail, horse barding, and swords

3

Audience chamber or throne room. Columns or martial statues line the walls

4

A banquet hall with a huge central table stacked with drinking horns and platters

5

A mess hall for servants or soldiers. Rows of tables and chairs are set with clay bowls

6

A guardroom decorated with war banners and shields. Several round tables are littered with candles, card decks, and empty bottles

7

A kitchen; a cauldron of soup simmers inside a blazing fireplace

8

A store room containing barrels of foodstuffs and crates of weapons

9

A training room with target dummies. The floor is strewn with armor and weapons, and several cracked mirrors line one wall

10

A prison containing several prisoners manacled to a wall

11

A ballroom with a balcony accessible by a rickety staircase. On the balcony are dozens of instruments

12

A crypt containing stone caskets

Dungeon Mounts

Dungeon Mounts

While horses are poorly suited to dungeons and caverns, dungeon denizens tame and ride many other creatures. Besides mules and mastiffs, which can thrive as underground mounts, the following creatures can be used as mounts by those who can tame them. Their riders gain the advantage of their different forms of movement.

Table: Mounts

Item

Cost

Speed

Carrying Capacity

Strength 

Giant Lizard

100 gp 30 ft., climb 30 ft. 420 lbs 14

Giant Spider

400 gp

30 ft., climb 30 ft.

420 lbs.

14

Giant Toad

200 gp

20 ft., swim 40 ft.

420 lbs.

14

Shadow Elf Equipment

Shadow Elf Equipment

Shadow elves often find themselves on the front lines against the undead who stalk the caverns of the world below, and have armed themselves accordingly. Against foes whose mere touch can paralyze or kill outright, mobility, protection, and the ability to keep enemies at bay are top priorities. To achieve these aims, the shadow elves turn to their bestial allies, the myriad of giant spiders living underground. Weaving armor from their silk and creating their own versions of the spiders’ webbing, shadow elves face their deathless foes not as quavering prey, but as apex predators.

Dark Iron. Found only in the most lightless depths of the world, dark iron is comparable to adamantine in many respects. Though incredibly durable, the metal has a critical weakness: it dissolves almost instantly in sunlight. Dark iron weapons or armor that spend 1 round in direct sunlight become pitted and obviously worn. A second round causes the item to acquire the broken condition (a broken weapon deals half damage and broken armor provides half its AC bonus, rounded down). A third round causes the item to disintegrate to nothingness.

 

Item

Cost

Weight

Mycellium Stake 15 gp -
Radiant Trap 70 gp 2 lbs.
Spiderweb Bomb 60 gp 1 lb.

 

Mycelium Stakes. These stakes are just as effective at destroying vampires as those made of wood, but they have an additional benefit: when driven into the corpse of a creature, the mycelium in these stakes creates a fungal colony that slowly consumes the corpse, preventing it from returning as an undead. The fungus can consume the corpse of a newly dead creature in 1d6 days, but it works much faster on undead flesh, destroying such remains in a mere 1d4 hours.

Radiant Trap. This metal sphere is perforated with dark iron plugs and filled with pressurized holy water. When the sphere is rubbed with glaring oil, takes at least 1 point of radiant damage, or enters an area of natural or magical sunlight, the plugs dissolve, spraying holy water in a 10-foot radius around the trap. Undead and fiends in the area must make a DC 13 Dexterity saving throw , taking 2d6 radiant damage on a failed save or half the damage on a success.

Spider Silk. This incredibly light and strong cloth is made from woven spider silk. It can be used to create light armor and textiles. Cloth and rope made from spider silk has twice the usual number of hit points, and the AC and the DC to break spider silk rope increases by 2. The difficulty of weaving with spider silk accounts for its high price.

Spiderweb Bomb. A creature can use an action to throw the bomb up to 30 feet at a point it can see. When it lands, the bomb detonates into a mass of sticky webs in a 10-foot radius. If there are at least two solid surfaces within 10 feet of the bomb, the strands adhere to them, creating a lightly obscured area of difficult terrain. The webs dissolve after 30 minutes. A creature in the bomb’s detonation radius or that enters the area while the webs remain must make a DC 12 Dexterity save or be restrained . A restrained creature can escape the webs by using its action to make a DC 14 Strength check. Each 5-foot cube section of the webs can be hacked through (AC 11, 12 hit points, immunity to poison and psychic damage) or burned. A creature restrained by the webs when the webs are burned takes 2d4 fire damage.

 

Material

Description

Cost

Properties

Repairability

Dark Iron

Comparable to adamantine in its physical characteristics, dark iron is an inky black metal with a faint purplish iridescence.

×4

Hardy, lightweight

DC 25

smith’s tools, access to a forge

Spider Silk

Spider silk is the spun webbing of giant spiders. It is incredibly light and strong. It can be used to make light armor.

800 gp + 10 x the usual price of the item

Comfortable, fortified

DC 25

sewing kit

Pagination