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Demogorgon Must Die: A Twenty Level D&D Campaign Outline

by Mike on 10 May 2021

This article outlines a twenty level campaign centering around the sinister plots of the demon prince Demorgorgon. Like The Hunger and Harvester of Worlds, this outline describes location-based adventures for each tier of play following a central arc. It's intended to inspire your own campaign outlines, offer subplots you can weave into your own campaigns, or even inspire your own Demogorgon-based campaign. Enjoy!

Campaign Elevator Pitch

Demogorgon begins a war...against themselves! Aameul, the charismatic and calculating head of the twin-headed demon prince plants the seed of a plot to finally split from their brutal chaotic other half, Hethradiah. All that must be done is to die. Unfortunately, such a feat will destroy much of the world along with it and birth a new chaotic demon prince in the process. The characters must untangle this thread, protect the world from the demon prince's war, and perhaps destroy the demon prince forever.

The Six Truths of Demogorgon Must Die

Cults are on the rise in the region.
Mutated livestock have been born with two heads.
Twisted nightmares pushed orc and goblinoid raiders back deep into their caves.
Strange shadows and ghouls rise from fetid swamps attacking local villages.
Strange symbols appear in ancient swampy caves, black myres, and forgotten grottos.
Local lords and regional kings began conscripting and mobilizing armies for a coming war.

1st Level: A Missing Mind

The campaign begins with the characters conscripted by an elderly mother whose son has gone missing in the nearby woods. Nightmares told the old woman that something unfathomable and sinister grips her son's body, lifts him, and pierces into his skull with a black tentacle.

The characters find the poor lad, comatose, with no visible wounds. A strange glyph has been burned into the grass surrounding the young man. Shadows (one for every two characters) slide out of the woods speaking in the abyssal tongue of the Deep Father as the lad rises up as a ghoul. The characters return to the woman with their grim news and reach 2nd level.

2nd to 4th Level: Rise of the Sibilant Beast

The characters uncover signs of not one but two cults vying for power in the region, each seeking to draw their own demon prince into the world and build it's throne.

Ruins of the Hungering Maw. The characters follow the signs of a nearby cult to ancient ruins of a dark keep. There they discover cultists pulling a demon out of the Gaping Maw.

Monastery of the Still Mind. Following the leads of those whose minds have been shattered, the characters travel to a nearby monastery supposedly helping those victims. Instead they discover an entirely different cult devouring the consciousness of their victims.

Altar of Spiraling Depths. Following clues from both cults, the characters travel to an underground temple where the Cult of Aameul and the Cult of Hethradiah wage war against one another only to find that both cults follow the same being — Demogorgon!

5th to 10th Level: The War of Spiraling Depths

The cults of Aameul and Hethradiah wage war across the land, corrupting kings and murdering hundreds as they crash together. The characters begin to unweave the plot of the twin-headed demon prince.

The Sundered Village. The characters travel to a village overtaken by festering ghouls and cultists of Hethradiah.

Pits of the Black Mire. The characters learn of a festering pit hidden away in the Black Mire where the Cult of Hethradiah spawns terrible psionic-empowered ghouls attacking neighboring villages.

Library of the Imprisoned One. In order to understand the true depths of the twin cults and the horror they worship, the characters travel to the library of Helm. There in the forbidden stacks, they discover that a sect of Helm's priests and paladins have supported Aameul for centuries.

Horror from the Gaping Maw. Vithriax, a two-headed troll priest, uses the power of both cults to call horrible demons out of the ancient gateway of Ix. The characters must travel to the gateway, face its demonic hordes, and close the portal to end the infestation.

Palace of Shattered Minds. The characters learn that the Cult of Aameul have dominated the minds of the rulers of Wyndgard palace, the city surrounding it, and the armies that protect it. The characters must make their way into the palace and break the Sphere of Aameul dominating the lords.

Warlocks of the Twisting Serpents. The characters travel to the spire of Twisted Serpents to face the yuan-ti warlocks of Demogorgon; the only followers who understand Demogorgon's duality. Only they know the true drive of both Aameul and Hethradiah.

11th to 16th Level: Discordia

The character learn that in order to save the world they must slay the avatar of Demogorgon in the world, acquire the only weapon capable of killing Demogorgon in their home world of the Gaping Maw, and travel to that accursed world to end Demogorgon's reign of destruction.

Return to Darklake. Years ago the kuo-toa summoned Demogorgon to the underdark through sheer force of will. How they did so remains a mystery sunken in the depths of Darklake. The characters must make their way to the ruined kuo-toa city and face the horrors they have manifested through their own mad callings before reaching the ruins beneath the black water and discovering the prophecy speaking secrets of the twin-headed demon prince.

The Bloodfields. Twisted by the influence of both Aameul and Hethradiah, war rages in the land. Deformed giants and demons led by the twin-headed ancient black dragon Selivis Twintongue fight the mind-twisted armies of the city of Wyndgard in league with Aamuel. The characters must find a way to stop both armies before they destroy every town and village stuck between them.

Hall of Secrets. Far in the frozen north lives a lich sage trapped in his own unhallowed halls. Having long-since given his soul to extend his life, the lich, Xorrus, is the only being who has discovered the true secret of Aameul's plot, the location of the weapon capable of destroying Demogorgon, and the yawning gateway that leads from this world to Demogorgon's own world, the Gaping Maw.

City of Shattered Mines. The avatar of Demogorgon destroys the city of Wyndgard, shredding bodies with its twisted tentacles and minds with its psionic attacks. The characters must return to the broken city, face, and defeat the avatar before it continues its reign of destruction.

Castle Discordia. The characters track back the trail of the avatar of Demogorgon to the legendary Castle Discordia, an ancient keep once thought to be pure myth. In its twisted halls and endless chambers the characters must find the portal to the Gaping Maw and the weapon capable of slaying the demon prince forever, guarded by Demogorgon's most powerful cultists and guardians.

The Gaping Maw. In the depths beneath Castle Discordia, beings of pure nightmare lurk in the darkness, never having seen the sun of the world above. The most loyal cultists, priests, and archmages in service to the cult of the Deep Father guard the portal between the world and the Gaping Maw. If the characters wish to save the world above they must enter the portal and close it from the other side.

17th to 20th Level: Death and Birth in the Gaping Maw

The characters step into the Gaping Maw, the abyssal layer of Demogorgon where the demon prince's war has shattered the plane. There they must make their choice to follow through with Aameul's plot, betray Aameul to Hethradiah, attempt to kill Demogorgon, or slay the resulting new demon prince rising from Aaemul's treachery.

The Brine Flats. The characters traverse an endless shore of white bones along the acidic oceans of the Gaping Maw. They come across the ruins of cities and temples fallen from other worlds and torn apart by the rampages of twisted undead and mutated demons before making their way to the gates of the Endless Jungle.

The Endless Jungle. The characters navigate the swamps and jungle stretching from the Brine Flats to the tower of Abysm. They find themselves hunted by the broken fomorian hunters of the jungle who serve the twin dracolichs who sired Selivis Twintongue.

The Towers of Abysm. The characters crawl through the catacombs beneath the twin twisted towers of Abysm seeking an entrance through the maddening labyrinth. Climbing within they face their own worst memories, torn from their minds and manifested. Along the way the final plots and seeds of both Aamuel and Hethradiah slide through the minds of the characters, offering them eternal glory should they side the right way.

Death and Rebirth. In the highest reaches of the Towers of Abysm the characters face Demogorgon's final guardians and uncover Aameul's sarcophagus containing their new body. In the final chamber the characters must defeat Demogorgon and their protectors before siding with one head over the other or choosing to destroy both and create a vacuum for something new. The decisions they choose change the face of the multiverse forever.

An Outline for Inspiration

The goal for an outline like this is to inspire your own campaign ideas and show one approach for outlining an entire campaign without writing a novel's worth of situations that may never come to pass. Campaign outlines give us the freedom to fill out an entire 1st to 20th level campaign arc without creating material that never hit the table. Hopefully this arc inspires your own campaign seeds and the adventures you share around the table with your friends and family.

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