This week’s encounter is a festive boss battle that you can run as a one-shot this holiday season. Each of your players assumes the role of a tremendously powerful being as they attempt to stop Mammon, archdevil of miserly greed, from destroying the holiday spirit of generosity.
The Heroes
Mammon is an archdevil of unimaginable power—to mortal beings, at least. However, there are creatures in the world that can aspire to defeat even an archdevil. Such rare beings are some of the most powerful beings in the multiverse, and now your players get to become one of them. An appropriate player character in this game would be:
- A 20th-level player character of your own creation
- A non-evil monster of CR 18 to CR 22
The latter category includes:
- Ancient brass dragon (Monster Manual)
- Ancient bronze dragon (Monster Manual)
- Ancient copper dragon (Monster Manual)
- The sphinx Isperia, Guildmaster of the Azorius Senate (Guildmaster’s Guide to Ravnica)
- Leviathan (Mordenkainen’s Tome of Foes)
- Solar (Monster Manual)
- Zaratan (Mordenkainen’s Tome of Foes)
Good-aligned creatures like solar angels and ancient metallic dragons are likely to fight evildoers just for the thrill of it. On the other hand, some of these creatures are neutral, like the elder elementals known as Leviathan and Zaratan. They are less likely to do good deeds like defeating Mammon for good’s own sake. No matter who your players are playing as, you should encourage them to develop come up with a reason for them to want to defeat the forces of greed and return the spirit of giving to the people of the world.
The Villain and His Plot
Mammon, archdevil of miserly greed, has been summoned into the world after a rag-tag party of plucky adventurers failed to stop his evil cult. Now that the unlikely heroes have failed, Mammon has taken up residence in an ancient cavern north of one of the greatest cities in the land. In the Forgotten Realms, this city may be Waterdeep; in Eberron, it may be Sharn; in Greyhawk it may be the Free City of Greyhawk—or whatever magnificent city is at the heart of your own homemade campaign setting.
Mammon has captured Caritas, the Spirit of Generosity, an angelic being that encourages beings to give generously and compassionately and share health and happiness with others. In many ways, Caritas is Mammon’s antithesis, and his destruction will plunge the world into a hellish land of avarice and violent self-interest. Mammon has already used his evil cult to capture Caritas, and is planning to devour him and consume his power. Indeed, the archdevil has already consumed the angel of charity and is slowly digesting him. Mammon’s most powerful agents will keep him safe as he strips Caritas of his holy power. Mammon himself is a truly terrifying foe, but he is also guarded by his most powerful servants, including Bael, a devil of terrible power known as the Bronze General.
Beginning the Adventure
This adventure begins once the players have chosen their characters, and Caritas, the Spirit of Generosity, appears before them. You can read or paraphrase the following text to set the scene. This text is deliberately ambiguous as to whether or not the characters are already gathered together, allowing you to start gameplay with the an established party of characters hearing the message together, or for a group of strangers to meet for the first time as they gather outside of Mammon’s lair.
A voice fills the evening air. It is gentle and soft, but filled with pain. “I know not who will hear this message, only that I seek the most powerful beings close enough to hear my call. Hear it well. My name is Caritas, and I am the angel of generosity. I was to inspire the people of the world to cherish their fellow beings over the Midwinter holiday.” As the voice stammers, an ethereal vision appears in the corner of your vision. He is tall and graced with a head of gentle curls, but his hands are bound and his face is lined with sorrow.
He composes himself and continues. “Mammon, lord of greed, has stolen me from the heavens and prepares now to be my executioner. Between his occult minions and the devils at his command, I fear that the spirit of the holiday is doomed. Please, if you have the power to oppose a lord of the Nine Hells, help me. Help save Midwinter.”
The angel’s voice echoes in the snowy-filled night air, and the vision fades.
Optional Travel Montage: The Journey to Mammon’s Lair
Creatures as powerful as the heroes of this adventure probably have easy ways to travel vast distances over a very short time. As such, this is just an opportunity for the players to creatively describe how they arrive at the lair. This gives the players a chance to directly control the story, before they are bound by the rules of combat later on.
An ancient dragon could easily carry an entire party of humanoids on their back, and angels can transport themselves with ease. Elder elementals can’t move quite as efficiently, but a creative player could still make their journey plausible and interesting. Leviathan might transform into pure water and travel through rivers straight to Mammon’s lair, or Zaratan might simply be summoned from the Elemental Plane of Earth directly adjacent to Mammon’s lair.
If you want to expand this short travel montage, consider reading other articles on travel like Exploring the Wilderness: Navigation and Player Agency and Traveling with Style: Skill Challenges.
Arrival at the Mountain of Evil
Mammon’s fortress is a massive cavern within a desolate mountain, some ways north of anything that could be considered civilization. A bitter wind rips around the mountain, and snow so thick that no being can fly through it pelts the ground. A row of eerie lanterns containing flames that flicker the color of gold illuminate a path that leads to the mouth of the cave.
A group of twenty cultists and five mages stand outside the mouth of the cave, dressed in thick furs. They huddle by their strange golden fires and keep a lookout for intruders, but the terrible weather conditions make vision beyond 60 feet all but impossible for them. If the player characters have alternate forms of vision, such as blindsight or truesight, they can easily surprise this pack of greed-blinded fools.
Terrain. The entrance to Mammon’s lair is a roughly circular plateau that’s 60 feet in diameter. A 50-foot-high cave mouth stands at one end, and leads into the lair. The cultists’ camp is in the middle of the plateau.
Golden Flames. The flames of the fires in this lair, as well as the flames of any spell cast by Mammon or his minions that deal fire damage, burn gold with the power of Mammon’s infernal greed. They possess the power of hellfire, as described in Baldur’s Gate: Descent into Avernus. Any humanoid killed by this fire has its soul funneled into the River Styx, where it’s reborn instantly as a lemure.
Tactics. These cultists don’t stand a chance against beings as powerful as the player characters, and they know it. In the first round of combat, the mages roar for the cultists to hold ranks and attack, while they use their strongest spells. However, half of the cultists break ranks and flee into the mouth of the cave. If they get inside, they alert Bael and his minions, who prepare for the characters’ arrival in the next encounter.
Combat Encounter: Battle with Bael
A tunnel leads from the cavern’s massive entrance to a two-tiered chamber; the first tier is chilly and filled with Mammon’s cultists, while the second, ice-rimed tier exists 30 feet below, and is filled with treasure tithed to the lord of greed himself. Mammon’s greatest general, the bull-headed Bael, commands his occult warriors in defense of the lair. Fighting alongside Bael are twenty cultists, ten barbed devils, and a power-hungry bone devil known as Lieutenant Kress.
These cultists are all but completely insignificant to the player characters; you can safely describe their attacks with no mechanical effect, treating them as cannon fodder to be mowed down.
You can use this map, borrowed from Hoard of the Dragon Queen, to represent the front entrance to Mammon’s lair, the tunnels leading inside, and Bael’s antechamber.
Tactics. Bael is a commander first and a warrior a very close second. He prefers to use his dominate monster and symbol spells to weaken his opponents while letting his minions do his work for him. However, he quickly pivots to the front lines and fights with his Hellish Morningstar if the battlefield isn’t under control once he’s cast these spells. The barbed devils use their Hurl Flame action until the characters are in melee range, and then attack with their claws and tails. The bone devil buzzes through the air, attacking foes that are preoccupied fighting the devil’s allies.
Prepared or Not. If the inhabitants of this area aren’t prepared for the characters’ arrival, the barbed devils and cultists are milling about in the upper chamber while Bael and the bone devil are deep in conversation by the treasure hoard. If even one of the cultists ran in from outside and alerted them, all of the combatants here have hidden themselves and prepared an ambush. The cultists and barbed devils hide in the passages in the south of the upper chamber while the bone devil clings to the roof of the upper chamber, and Bael buries himself in the treasure hoard.
Treasure Hoard. The mound of gold in this room is but a small fraction of the wealth Mammon has amassed. It contains approximately 500,000 cp, 100,000 sp, and 10,000 gp.
Combat Encounter: Battle for Midwinter
Traveling through the icy caverns in the southwest of Bael’s chamber sends the characters winding into a sweltering vault deep below the mountain. Here, Mammon lounges upon a veritable ocean of wealth, containing untold millions—perhaps billions!—of gold coins from across the multiverse. At the apex of this towering vault hangs Caritas, his entire body enwrapped with chains held by four chain devils.
Mammon has been torturing and slowly relishing his capture of his angelic counterpart, but he fully intends to eventually destroy the celestial and consume his power. Once the characters enter this chamber, Mammon casts fly and springs into action, soaring to the pinnacle and tearing into the angel (described in “Caritas, Spirit of Generosity,” below).
You can use this map, borrowed from Rise of Tiamat, to represent the heart of Mammon’s lair. Area 1 is the entrance, and area 2 is the main floor. The cavern is 200 feet high, and areas 7 through 12 are the same chamber, 100 feet above the ground, and area 13 is the same central chamber, 200 feet above the ground.
Mammon, Lord of Greed
Mammon’s natural form was once of a bloated pit fiend. Although he can still adopt that form, Asmodeus has altered him so that his natural form is that of a [huge] serpent with a muscular humanoid torso, sporting two large arms and a massive humanoid head. His mouth has pointed teeth and two large snake fangs.
—The Book of Vile Darkness (2001)
Mammon uses the statistics of Moloch, as presented in Mordenkainen’s Tome of Foes, with the following changes:
- The Breath of Despair ability doesn’t frighten creatures. Instead, a creature that fails its Wisdom saving throw is charmed by Mammon for 1 minute. While charmed in this way, the creature’s mind is filled with terrible envy, and it must use its action to make at least one melee weapon attack against a creature that is hostile to Mammon. It can repeat the Wisdom saving throw at the end of each of its turns, ending the effect on itself on a success.
- Mammon wields a Hellish Shortspear rather than a Many-Tailed Whip. It is a Melee or Ranged Weapon attack with a reach of 15 feet or a range of 90/270 feet. It has a +15 bonus to hit and deals 15 (2d6 + 8) piercing damage plus 11 (2d10) fire damage. If the target is a creature, it must succeed on a DC 24 Constitution saving throw or have its speed reduced to 0 as it is wracked with terrible pain until the end of its next turn. If Mammon throws his spear, he can cause it to disappear and reappear in his hand as a bonus action.
- Mammon has three lair actions: Awaken Greed (same as Bael), Teleport, and Attack. All cost one action. Mammon’s Attack legendary action allows him to make one attack with his Hellish Shortspear.
In battle, Mammon cackles and taunts his opponents at every turn, promising them their hearts’ desire if they would only lay down their weapons and submit to his will. He uses his Bite attack on Caritas every turn he can, and uses his claw and Hellish Shortspear attack against the characters. The chain devils keeping hold of Caritas use one hand to continue to restrain the angel and the other to attack the characters.
Caritas, Spirit of Generosity
Caritas is a solar bound by infernal chains. While even a single one of the four chain devils holding him continues to do so, he is restrained, and is blinded and paralyzed while restrained in this way. If he is freed, he fights alongside the player characters, but has three levels of exhaustion.
Caritas has 121 hit points remaining. If he is reduced to 0 hit points, all hope is lost. Once at 0 hit points, Mammon can devour his essence as an action, transforming the archdevil into a being of infernal power beyond anything the player characters can hope to oppose. All creatures within 1000 feet must make a DC 30 Constitution saving throw, taking 550 (100d10) necrotic damage from Mammon’s hideous transformation on a failed save, or half as much damage on a successful one. Moreover, the spirit of generosity and charity vanishes from the world, leaving its inhabitants selfish and avaricious.
Conclusion: Goodwill Towards All
If Mammon is defeated, his physical form disintegrates and he is sucked back into the Nine Hells where he painfully recorporates in his sinking palace. Caritas is saved, and the spirit of selflessness and generosity is returned to the world—just in time for the holidays where these virtues are valued the most. The darkest days of winter come to the land—but a candle shines in every window. The homeless are given shelter, gifts are given between friends, and charity and kindness are shown to every stranger. The world is, if only for a brief moment, at peace.
Did you like this encounter? Check out the other encounters in the Encounter of the Week series. You can also pick up the adventures I've written on the DMs Guild, such as The Temple of Shattered Minds, a suspenseful eldritch mystery with a mind flayer villain. My most recent adventures are included in the Platinum Bestseller Encounters in Avernus, a collection of over 60 unique encounters created by the Guild Adepts, which can be used to enhance your campaign in Avernus or elsewhere in the Nine Hells. Also check out the Platinum Bestseller Tactical Maps: Adventure Atlas, a collection of 88 unique encounters created by the Guild Adepts, which can be paired with the beautiful poster battlemaps in Tactical Maps Reincarnated.
James Haeck is the lead writer for D&D Beyond, the co-author of Waterdeep: Dragon Heist, Baldur's Gate: Descent into Avernus, and the Critical Role Tal'Dorei Campaign Setting, a member of the Guild Adepts, and a freelance writer for Wizards of the Coast, the D&D Adventurers League, and other RPG companies. He lives in Seattle, Washington with his fiancée Hannah and their animal companions Mei and Marzipan. You can find him wasting time on Twitter at @jamesjhaeck.
Or Dispater, he's going to be present in my current Descent into Avernus game.
100d10 ... Wow!!!
Oh how will I some how make sure my party will so I can do this?
What a great encounter, as usual, James! Thanks for this.
I really like this game! I love D&D games that have a theme! They are so entirely fun and this one is too above all because it is saving Christmas basically!
Not only for the Mephistopheles stat block, but also because it is such a comprehensive and excellent product, I would suggest checking out the Monster Manual Expanded, Vol. II by Dragonix on the DMsGuild website. It also has lower CR aspects of Mephistopheles (and other archdevils)
As I suggested to MephistophelesBard, check out the Monster Manual Expanded, Vol. II by Dragonix on the DMsGuild website. It has a stat block for Dispater and also lower CR aspects of Dispater (and other archdevils).
My players are having a lot of fun with this campaign, but is taking longer than 1 night. Maybe it's because we only had 2 1/2 hours to play, but we only got about half way through. We do have plans to finish at our next session on 1/2. My players like to roll play a lot of the game so it's been very enjoyable! Love it. Thanks!
this is a wonderful article! also, has anyone noticed it's been a week since we got a new article? what's up with that?
We just played this adeventure in our weekly FLGS group.
An ancient gold dragon
A reformed Lich
A goblin Rogue with a Crossbow
And A Goliath Barbarian (Santa Conan)
The dragon used the coins from the first chamber in his belly as a gatling to gun down the Chain Devils and free Caritas.
I made a CR 28 stat block for Dispater
Dispater
Large fiend (devil), lawful evil
Armor Class: 27 (adamantine armor)
Hit Points: 627 (45d10 + 380)
Speed: 50 ft.
Str 22 (+6) Dex 26 (+8) Con 28 (+9) Int 28 (+9) Wis 27 (+8) Cha 30 (+10)
Saving Throws: Int +17, Wis +16, Cha +18
Skills: Intimidation +18, Perception +24, Persuasion +18
Damage Resistances: acid, cold, fire, lightning, radiant; bludgeoning, piercing, and slashing from attacks that aren't adamantine
Damage Immunites: necrotic, poison; bludgeoning, piercing, and slashing from nonmagical attacks
Condition Immunites: charmed, exhaustion, frightened, poisoned
Senses: darkvision 120 ft., truesight 30 ft., passive Perception 34
Languages: All, telepathy 120 ft.
Challenge: 28 (120,000 XP)
Abilities:
Adamantine Suit: Dispater has resistance to acid and lightning damage and immunity to bludgeoning, piercing, and slashing from nonmagical attacks while wearing his suit. He also gains truesight out to 30 ft.
Devil's Sight: Magical darkness doesn't impede Dispater's darkvision.
Greater Magic Resistance: Dispater has advantage on saving throws against spells and other magical effects. Once per turn, as a reaction, Dispater can cancel the effects of a spell of 6th level or lower.
Innate Spellcasting: Dispater's innate spellcasting ability is Charisma (spell save DC 26, +18 to hit with spell attacks). He can innately cast the following spells, requiring no material components:
At will: alter self (can become Medium when changing his appearance), arcane eye, charm monster, detect magic, glyph of warding, invisibility (self only), phantasmal killer, storm sphere
3/day each: delayed blast fireball, dominate person, modify memory, symbol (only discord, fear, or insanity)
1/day each: dominate monster, feeblemind, power word stun
Legendary Resistance (3/day): If Dispater fails a saving throw, he can choose to succeed instead.
Regeneration: Dispater regains 20 hit points at the start of his turn. If Dispater takes radiant damage, this trait doesn't function at the start of Dispater's next turn. Dispater dies only if he starts his turn with 0 hit points and doesn't regenerate.
Anyone know how I can join a group for DnD
You can find Adventure League games here https://dndadventurersleague.org/start-here/
Some game cafes have open DnD where you can get into open games.
Or you can join a forum game here under the forum tab. Roll20 also has games you can join.
i would love to DM this.
Minor correction, in the description of Mammon, you put he has the same lair actions instead of saying legendary actions.
I'm sorry if I missed but for how many players it's intended to be played? I assume 4-5, but I would love to hear recomendations
lol I just got an account. How do u play this game..... I have no idea. HELP MAH
Check out the New Player Guide at the top of the page.
just to add to this,
i found that a Solar is incredibly powerful in this... i highly recommend not allowing your players to use it.
At the end of the day, the encounter already breaks most stereotypes and it is a one-shot, so a single broken character doesn't make too big of a difference as long as the players all have fun.