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AREA 1 – ILLUSORY WALL

The stairs from the White House bottom out into a small room with an iron chest.

ILLUSORY WALL: The wall immediately to the north of the stairs is illusory, created with a major image spell (cast using a 6^th level spell slot to make it permanent). A DC 21 Intelligence (Investigation) is required to discern the illusion for what it is.

WIGHTS (12): There are 12 wights (MM, p. 300) behind the illusory wall. They attack when the trap on the iron chest is activated (they can see through the wall without any problems) or if anyone passes through the wall.

IRON CHEST: Empty. It is locked (DC 13) and trapped. (DC 18 to detect). Anyone touching the chest must succeed at a DC 14 Constitution saving throw or become paralyzed. In addition, they exude a carrion stench for 2d6+2 rounds that causes all creatures within a 10-foot-radius to become poisoned for 1d6 rounds unless they succeed at a DC 14 Constitution saving throw. (Characters must repeat the saving throw for each round that they remain within 10 feet of the stench-exuding victim.)

AREA 2 – THE DOOR CHOICE TRAP

The north door in this room is gilded with silver. The south door is gilded with gold. Each door has a magic mouth.

ENTRANCE SCRIPT: Entering the room from Area 1 triggers the following script from the magic mouth. Leaving the room and re-entering will trigger the script again.

• Both Doors: Each of us will ask a riddle. To pass us you must answer true.
• Door of Gold: One shall always tell the truth.
• Door of Silver: One shall tell a lie.
• Both Doors: One question you may ask; then answer must be given.

FALSE SOLUTION: It’s a trick. If asked, “Will the other door tell me yours is the right path?” (or some similar circumlocution), then the Door of Silver will say “Yes” and the Door of Gold will say “No” (logically indicating that Silver is the correct door). But opening either door will trigger a fireball trap (14d6 fire, DC 20 Dexterity saving throw for half damage; Detect DC 14).

TRUE SOLUTION: Ask a door, “What is your riddle?” Then answer the riddle accurately and the door will open safely.

GOLD’S TRUE RIDDLE:

Do not begrudge this,
For it is the fate of every man.
Yet it is feared,
And shunned in many lands.
Causes problems, and sometimes gaps,
Can hobble the strongest, and make memory lapse.
What is this danger we all face?
For being part — of the human race.

ANSWER: Old age.

SILVER’S TRUE RIDDLE:

With this you can do wondrous things.
Look at things close or far away.
You can see things big,
Or you can see things small.
Or maybe you don’t see them at all.
I come in many colors and hues,
Sometimes green and sometimes blue.
And when I’m read — it’s not from shame.
But from something with a different name.

ANSWER: Eyes.

AREA 3 – WIGHTS, GHASTS, AND A FALSE DOOR

There are 6 wights (MM, p. 300) and 6 ghasts (MM, p. 148) in this room.

FALSE DOOR: Fashioned of copper. Touching the door triggers a chain lightning trap (10d8 damage, DC 20 Dexterity saving throw for half damage, leaps to 6 additional targets; Detect DC 16).

AREA 4 – ANTECHAMBER

A cream-colored carpet runs across a beautiful floor of crimson-patterned tile. A picture of a young man hangs on the north wall; a picture of a ghastly, skeletal figure hangs on the south wall.

NORTH PICTURE: Depicting a youth with chocolate brown hair, darkly tanned features, and dressed in robes of blue silk. Purple lightning dances between the fingers of an out-stretched hand. (This depicts Aggah-Shan as he was in life.)

SOUTH PICTURE: Desiccated features, but wearing the same robes of blue silk. The figure is wreathed in flame, with the sun limned in eclipse behind him. (This depicts Aggah-Shan as a lich.)

AREA 5 – BLADE BARRIER TRAP

TRAP: Any living creature entering the 10’ x 10’ area between Area 4 and Area 6 triggers a blade barrier which blocks all four directions out of the 10’ x 10’ area. This simultaneously triggers the trap in Area 6.

• Magical trap
• 6d10 slashing damage (DC 20 Dexterity saving throw for half)
• DC 14 Intelligence (Investigation) check to detect the trap.
• DC 20 Intelligence (Arcana) to identify the nature of the trap.
• A dispel magic spell permanently disables the trap.

AREA 6 – ULULATING FOUNTAIN

A statue of a wraith-like maiden with her mouth gaped wide serves as a fountain, pouring a black-tinted water into the stone pool below.

UNHOLY WATER: The water in the pool is unholy water (30 vials worth).

TRAP: Any living creature touching the water or the statue triggers a trap.

• Magical trap
• DC 16 Intelligence (Investigation) to detect the trap.
• DC 14 Intelligence (Arcana) to identify that the trap will transform the water; DC 18 check reveals the full properties of the trap.

Poison Cloud: The water emerging from the siren’s mouth is converted into a poison cloud. (DC 16 Constitution saving throw or suffer 4d6 poison damage and become poisoned; the saving throw must be repeated each round.) The cloud expands 10 feet per round to a maximum radius of 60 feet (filling this entire level out to Area 2).

Siren’s Song: The statue begins ululating a siren’s song. Living creatures within hearing must make a DC 16 Wisdom saving throw each round or become captivated, moving towards the fountain and then drowning themselves in it. (Those moving through danger — such as the blade barrier in Area 5 or the poison cloud — have advantage on the saving throw.)

Alerting the Complex: The siren’s song will bring any wights and ghasts from Area 3 or Area 10 that are still alive. Everyone else in the complex will maintain guard positions, but will be alerted.

AREA 7 – VASES OF LITHUIN

A collection of nineteen vases placed on pedestals around the room Some are fluted ceramics, while others are more finely crafted and crystalline in nature.

INTELLIGENCE (HISTORY):

• DC 18: These are Lithuin vases. Incredibly rare. Individual vases are worth 1,000 gp each.
• DC 26: This collection specifically demonstrates the evolution of Lithuin vase-craft. It’s unusually complete, and its collected value would be doubled (to 38,000 gp).

INTELLIGENCE (HISTORY) or (INVESTIGATION) – DC 20: The vases are covered in Lithuin runes (now undecipherable), but two of the vases also have a different symbol carved on their bottom:

DM Background: The symbol is that of the Shuul (Ptolus, p. 126). These vases were purchased from the Shuul (who make regular archaeological expeditions to Lithuin).

LITHUIN

Lithuin is a semi-legendary city that was inhabited by Titan Spawn who “sailed from beyond the sea.” They were specialists in the arts of kaostech. The location of the city was long-lost and many scholars believed it never actually existed. Various chaos cultists, however, have recently rediscovered it, and the Shuul have also come into possession of its secret location.

AREA 8 – COPPER FOUNTAINS

Several shallow copper basins are on the floor of this area. Other basins are suspended from the ceiling or built out from the walls. Copper tubing runs in tangled mazes throughout the chamber, gushing forth with multi-hued liquids here and there, creating kaleidoscopic pools of effervescent hues.

SECRET DOOR (Detect DC 15): Twisting one of the spigots causes a large basin to drain and then spin out of the way, revealing the passageway to Area 9 behind it.

Playtest Tip: Although this may initially appear to be the only route to the lower levels of Aggah-Shan’s Catacombs — in which case having a mandatory skill check to get down there would be a questionable choice — in practice these catacombs can also be approached from the OTHER direction (exploring up out of the Mrathrach Machine). In addition, triggering an alarm will cause the wights and ghasts in Area 10 come up; they will leave the secret door open, revealing its location.

AREA 9 – WHIRLING POISON BLADES

The stairway is filled with poisoned blades that come whirling out of razor-thin slits in the walls. Putting any weight on five of the stair treads will trigger the trap (which remains in motion for 5 minutes).

• Mechanical trap
• DC 12 Wisdom (Perception) check to notice the razor-thin slits in the wall.
• DC 14 Intelligence (Investigation) to identify the trap; DC 16 identifies 1d4+1 trigger treads; DC 18 identifies all five trigger treads.
• DC 16 Dexterity (Thieves’ Tools) to disable.
• +8 attack bonus, 3d10 slashing damage, DC 14 Constitution saving throw or 2d6 poisoned damage. Targets all characters on the stairs when triggered.

Go to Part 2C: The Lower Catacombs

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Frostbanes are skeletal figures case in ice, but with a flame burning within their chest. Through its icy sheath, this flame burns fiercely — usually in shades of blues, but often purple or green or even crimson.

The Frozen Damned. Frostbane are powerful undead created from corpses which have been frozen for at least a century (usually within icy glaciers, although there are tales of reaping fields upon the Plane of Ice which are maintained and harvested by ancient liches patient enough to mortal lifetimes for their schemes to unfold).

Ice & Fire. Their existence is born from paradox and their mockery of life sustained through an antithetical balance of elemental forces, for the necromancer kindles within their frozen breast a magical flame. This flame slowly consumes their dead flesh, but does not affect the ice which was their death and tomb. Thus heat and frost are maintained in an eternal, impossible tension.

The frostbane thus thirsts eternally for the warmth it is denied — drawing in the heat of life and flame around it, but instantly converting it into the deathly grip of ice.

FROSTBANE

Medium undead, neutral evil

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Armor Class 17

Hit Points 98 (15d8+30)

Speed 30 ft.

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STR 15 (+2), DEX 16 (+3), CON 15 (+2), INT 11 (+0), WIS 12 (+1), CHA 8 (-1)

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Saving Throw Dex +6

Skills Perception +6, Survival +4

Senses passive Perception 16

Damage Immunities fire

Condition Immunities exhaustion, poisoned

Challenge 6 (2,300 XP)

Proficiency Bonus: +3

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Aura of Ice. Anyone within 40 feet of the frostbane suffers 4d6 cold damage per round (DC 14 Constitution saving throw for half damage) Anyone touching the frostbane suffers an additional 2d6 cold damage (no save). Anyone hitting the frostbane with a melee weapon suffers 1d6 cold damage (no save). Every 3 points of cold damage heals 1 point of damage to the frostbane.

Contingent Regeneration. If the frostbane is within 40 feet of a living creature or source of heat, it regains 5 hit points at the start of its turn. If the frostbane starts its turn at 0 hit points doesn’t regenerate, it enters a dormant state and appears “dead.” If someone approaches within 40 feet of the dormant frostbane, however, they can attempt a DC 14 Wisdom (Perception) check to notice an unnatural chill in the air. If the dormant frostbane remains within 40 feet of a living creature or heat source for 5 minutes, it will rouse from its dormancy (and begin healing from itsaura of ice).

The frostbane only truly dies if it suffers cold damage while in its dormant state (snuffing out the flame at its heart).

Heart of Flame. Frostbanes are immune to fire damage and heal 1 point of damage for every 3 points of fire damage they otherwise would have suffered.

Frostspawn. Any humanoid slain by a frostbane rises as a zombie (MM, p. 315) in 1d4 rounds. There’s a 10% chance that such a zombie will transform into a frostbane 1d4 hours later. (There may be rites a necromance could use to increase these odds by helping to kindle its nascent flame.)

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ACTIONS

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 9 (2d6+2) cold damage.

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Frostbanes appear in The Mrathrach Agenda.

Go to Part 1

Beneath the White House are Aggah-Shan’s catacombs. This ancient lair actually predates the construction of the gambling house above by at least several decades, possibly more. It can also be reached from the Mrathrach Machine below.

(Download: Large – Battlemap)

(Download: Large – Battlemap)

Design Note: There is a map of the Lower Level of the White House on p. 311 of the Ptolus sourcebook. The maps here are designed to supersede that map.

Go to Part 2B: The Upper Catacombs

Go to Running the Hexcrawl

This post contains SPOILERS for Descent Into Avernus and the Avernus Remix.

The Avernian Hexcrawl was designed for Act III of the Alexandrian Remix of Descent Into Avernus. Intended for a dedicated table, the primary assumption is that the PCs will likely be exploring the hexcrawl in pursuit of the components required to repair a dream machine. It features 40-mile hexes with custom terrain, and we’ll also be using a different set of optional rules, including:

• variable travel distance
• the Avernian random encounter procedures
• the advanced rules for expedition speed

The PCs are:

• Kerstina, an Elturian hell knight
• Ereshkigal, a tiefling warlock
• Adi Themis, a halfling artificer

BEGINNING THE SESSION

The PCs have arrived at the Alvskraema caravanserai, located in Hex B2 next to the bridge which crosses the Pit of Shummrath. Ereshkigal’s infernal warmachine was damaged in a confrontation with a darksphinx and they came here looking for repairs.

Adi Themis realizes that the Alvskraema is serving elf meat as a delicacy, so they decide to pass on both the good and the common room. But while settling payment with Meltrus, one of the two forgemasters, Ereshkigal decides to go fishing and see if Meltrus has any leads on dream machine components.

Rolling on the Avernian rumor tables, I get this result:

Nirvanan cogboxes are used by modrons. I heard that the warlord Algoran recently captured a modron. His lair is located at the far end of the Ashlands. (Hex B6)

That’s perfect, so I just need to put that into Meltrus’ mouth:

Me (Meltrus): He strokes he wriggling, prehensile beard. “A Nirvanan cogbox, eh? Haven’t seen one of those in years. They’re mostly used by modrons, and there aren’t many of those around here. But you may be in luck. One of Algoran’s gladiators was in here a few days ago, spending his winnings on avariel goulash. He mentioned that Algoran’s out-riders had captured a modron recently.”

Ereshkigal: Algoran, huh? Where can we find him?

Me (Meltrus): “He founded a gladiatorial arena. It’s almost due south from here, built into the mountains that ring the far side of the Ashlands.”

The lead seems a little thin, but it’s close. So the PCs decide to check it out.

STARTING OUT

The PCs mount up on their infernal warmachines, which have a speed of 100 ft. They decide to travel at a fast pace, which means (using the advanced rules for expedition speed) that they’ll have a base pace of 60 miles per watch. This also means they’ll have a penalty to navigation checks, but they decide speed is more important and they won’t be able to get too far off course before they can see the mountains and navigate by landmark.

They’re starting in Hex B2 and heading south, intending to enter Hex B3. The terrain in both hexes is Wastelands and it’s Trackless, so they’ll be moving at ½ speed (30 miles per watch). They’ve already traveled one watch today to reach the Alvskraema, so they only have one watch of travel left. But they only need 20 miles of progress to reach Hex B3, so I know they’ll be getting there right at the end of their traveling day.

The group has a standard operating procedure while traveling: Kerstina takes the Navigator action, while the other two PCs take the Sentinel watch action.

As they start heading south:

1. I make a random encounter check, rolling 2d10 and 1d12. No encounter is indicated.
2. In addition to the normal random encounter check in Avernus, I also make an oppressive environment I roll 1d6, but no oppressive condition is indicated.
3. Kerstina makes her navigation check. The Wastelands are Navigation DC 12. She rolls a natural 20 for a total of 21. (20 + 6 for her bonus – 5 penalty for fast travel pace.) The groups heads due south without any difficulty.
4. Ereshkigal and Adi Themis make Wisdom (Perception) checks, but there’s nothing unusual to notice out here. I describe the broken scree of the Wastelands churning under their serrated wheels.

I mark 20 progress, which — as we determined — brings them to Hex B3. I check the key for Hex B3 to make sure there are no special conditions or visible landmarks (there isn’t), then I reset the progress counter to 0. They’ll need another 40 miles of progress to cross Hex B3 and enter Hex B4.

MAKING CAMP

Finished with travel for the day, the PCs circle up their warmachines. They decide to all take an active watch action, then take shifts for the rest of the night (with Kerstina, then Ereshkigal, then Adi Themis taking a watch with the Sentinel action).

For the first watch:

• Adi Themis makes camp.
• Ereshkigal reads some arcane texts they purchased in the Purple City.
• Kerstina takes the Forage action. The Wastelands Forage DC is 20 and, as a mortal, Kerstina has disadvantage on the check in Avernus. She fails. (But it was worth a shot.)

Although they’re not traveling, I once gain make a random encounter check. No encounter is indicated.

However, when I make the oppressive environment check, I roll a 1, triggering the condition. I then roll d12, getting a 3, which indicates extreme heat. I describe the temperature skyrocketing until the wasteland scree is steaming. Everyone needs to make a saving throw, and Kerstina fails. She comes stumbling back into camp not only empty-handed, but having suffered a level of exhaustion.

The PCs decide to shuffle things up: Kerstina needs to rest and can no longer take the first watch, so Adi Themis swaps with her. They decide to just wait out the extreme heat, as traveling under those conditions would be extremely debilitating. But they get lucky: The following watch I roll another 1 on the oppressive environment check, ending the condition.

I finish making the rest of the encounter checks for the night. During the sixth watch, an encounter is indicated. I roll d100 and determine the encounter would be with 5d10 imps. However, when I make the % Tracks check, it indicates that it would be a tracks encounter. That would be an exploration encounter, and since the PCs aren’t currently moving the encounter doesn’t happen.

HEADING SOUTH

The next day, the PCs load up and continue heading south. (Setting the same pace and so forth from the day before.) With 30 miles of progress per watch, I know they’ll reach Hex B4 during their second watch of travel (assuming nothing goes away).

In the first watch, I generate an encounter:

• d100 roll comes up 67, indicating a 1 yagnoloth.
• Tracks check and Lair check are both negative, so it’s definitely a yagnoloth.
• I roll a random encounter distance, determining that the yagnoloth will be detectable at 840 ft.
• I roll on the Avernian Reaction Table and discover that the yagnoloth will be Cautious/Threatening.

What’s the yagnoloth doing? Well, the write-up in Tome of Foes indicates that they’re often employed as contract negotiators. I decide he must be carrying (2d6) 4 pacts and (1d6) 2 soul coins to the adjunct court of Hell in Hex G1. Since he’s carrying some important material, I decide to go with Cautious more than Threatening.

And because the yagnoloth is Cautious, I decide to also make a Dexterity (Stealth) check, setting DC 13 for opposed Wisdom (Perception) checks.

The exact time of this encounter doesn’t seem to matter, so I don’t bother making an additional check to nail it down.

I now call for the PCs’ skill checks from their watch actions: A navigation check from Kerstina (which she passes) and Wisdom (Perception) checks from Ereshkigal (6, failure) and Adi Themis (18, success).

Since the PCs are traveling at a fast pace and can’t use Stealth, the yagnoloth has no difficulty spotting them.

I describe to Adi Themis the yagnoloth crossing the wastelands about several hundred feet off to the right of their path. I probably also hold up a picture:

So now what will the PCs do? Given the encounter distance and their relative speed to the yagnoloth, they may simply choose to steer wide and pass the yugoloth by. Or perhaps they’ll approach, hoping to glean more information about the region. (In which case, perhaps the yagnoloth will be the one to reveal how they can break the pact binding Elturel, if they haven’t figured that out already.) Or they may think the lone figure will be easy pickings and a chance to enrich themselves on whatever loot it may be carrying. (If so, who do the pacts the yagnoloth carries belong to? And will they come looking for them?)

A bit of local color to their journey or a pivot point which may change the entire course of the campaign? That’s the beautiful, emergent play of the hexcrawl.

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