No Prep Module: The Oathbreaker for D&D or RPGs

This adventure can be can be easily customized to a party of any size or level, or run as a level 8 adventure for 5 players. It can work as a small side adventure in an existing campaign, as a standalone one-shot, or the start of a new adventure. Use the links to the tools in their relevant section to customize the adventure to your party.

The Blackguard


The Blackguard Amduscia has made a deal with demons to conquer the lands and install himself as the new king. He has made his lair in a tropical oasis of hot springs, where the fabric between the planes has become unstable. From this base he has been seeking a powerful artifact weapon to bolster his army and destroy the kingdom. Recently a royal researcher has gone to the springs to study them, but hasn't returned.

The PCs find themselves in a small plane after being scooped up by a cosmic storm. They're on a beach, during a sahuagin seasonal festival with all sorts of tasty seafood dishes and games of skill. If the PCs partake in the food they'll find sahuagin dishes like fish roasted in clamshell, or seaweed wrapped prawns. The games include things like swimming competitions (speed, jumping through hoops) and throwing tridents at targets. Use relevant skill competitions depending on the game (such as Athletics) with competing sahuagin rolling a 1d20+1d6.

When the PCs want to leave, a DC 12 Arcana check will reveal that the cosmic storm has caused the planes to bleed together. In order to get back to their own plane they'll need to cause a wild magic surge. The trophy clamshell that the sahuagin are competing for is brimming with mana, but it's under guard. The PCs can either compete and win enough competitions to get near it, or convince the guards to let them near it (DC 17 Persuasion). Channeling magic through the trophy or otherwise damaging it will cause a wild magic surge, enraging the sahuagin but transporting the PCs safely back to their home plane.

Adventure Hooks

  • While outside, the adventurers hear a loud crash from over that way (far enough to be out of sight, yet audible). A short while later, they hear a booming voice cry out, "I've fallen, and I can't get up!" If the party investigates, they find an elderly giant has indeed fallen, and he or she can't get up.
  • A map has been found that leads to parts of an artifact that once reassembled, will summon a fiendish kraken.
  • The queen contacts the party and asks for their help.

If you use the first hook, the fallen giant will tell the PCs about Amduscia's plot. Not wanting war with the smallfolk, the elderly giant tried to stop Amduscia and had his leg broken in return. The elder giant will tell the PCs where to find Amduscia's stronghold as thanks for their help, hoping they can prevent an all-out war.

If you use the second hook, the PCs could either have found the map during a previous adventure, or at the sahuagin festival. One piece of the artifact can be found at Amduscia's stronghold.

If you use the third hook, the queen they meet with is Spring of World who asks the PCs to rescue the researcher Rohesia Huckabee who went missing in the springs shortly after discovering an army encampment. She hopes that the PCs will pose enough of a diversion to split the attention of the army, giving her retinue an opportunity to assault the hideout.

Spring of World, Female Tabaxi

Description: She is an athletic looking eastern young adult. She wears a fine suit in excellent condition, trimmed with graceful filigree. Her black fur is long and beautifully kept. She has gleaming, smiling green eyes.

Personality: She is quiet and unassuming. She ignores others and carries on with her job unassumingly. She tends to be very friendly, and is drawn to music, the smells of food and wine, and out-door festivals.

Voice: Puts emphasis on the wrong words

When the PCs are ready, they can travel to the tropical oasis of hot springs and steam vents in the jungle. The journey takes 2 days and they see there are huge holes and tunnels dug through the landscape, possibly by some sort of huge creature.

Navigation DC 15, Foraging DC 10. The temperature is 9°C (49°F) at day 5°C (415°F) at night. The weather is clear and sunny with heavy wind. Disadvantage on sight/hearing checks, and ranged weapon attack rolls. Extinguishes open flames, disperses fog, and makes flight impossible.

You come to a picturesque oasis of hot springs, vents billowing steam into the humid jungle. A cliff surrounds the area, with a large waterfall pouring into the stream below. The misty spray is cool and refreshing, intermixed with the heat from the springs. Wispy, ghost-like apparitions flicker into existence around the springs, occasionally looking like people. An ethereal vision of a person bathing in the springs pops into view for a couple seconds before dispersing, continuing all about the area.

The entrance to the dungeon is found behind the waterfall. The apparitions can't be interacted with, but if the PCs attempt to approach or speak with them the apparition will look at them in surprise before disappearing. Every room in the dungeon has these occasional apparitions that blink in and out as the PCs explore.

The Oasis

Blackguard Dungeon

Type: Ice Lair
Noises: Chiming
Air: Clear and damp
Odors: Smoky
Enemy Patrol: 1 Giant Spider (CR 1: Monster Manual p. 328), 2 Giant Swan (CR 1: The Wild Beyond the Witchlight pg 38), 1 Half-Ogre (Ogrillon) (CR 1: Monster Manual pg 238), 2 Troll (CR 5: Monster Manual p. 291) [Hard, 4,400 XP rewarded] [Customize]
Chance of Encounter Per Hour: 50%

Room Contents

You can also generate different descriptions using the Description Generator


This dusty, 35-foot-square room has a high-pitched ceiling that reaches its peak 30 feet above. The wooden rafters are shrouded in moss and leaves. Many quills and maps faded from the humidity lie showered on the floor, around two heavy wood chests fitted with sturdy iron locks. A river of water spills from a thin crack to the west and crosses the room, disappearing into a precarious, winding tunnel to the north.

If the locked chests (DC 17) are searched, they find 110 gp [Customize]

There is a north path that leads to #2


Tucked off to the side of the passageway is a modest bedroom containing a spacious bed, a small, crude table, and a hard mattress on the floor. A strong smell of rusty metal fills this room, in the front of which stands a rack of lances. A blanket of dust covers the tabletop with its cauldron and old dishware. The east end of this room has collapsed, exposing the room beyond.

An object in this room gives the user the ability to see if someone is nearing death.

Under the mattress is a key for the door in #3.

There is a east path that leads to #3

There is a south path that leads to #1


Moldy and lacerated skin is sprinkled about this 40-by-45-foot room. Swells of a constant symphony of birdsong come from elsewhere, echoing into the room. Directly across from the stone barred window stands a set of double doors in the south wall. Red coals glow from within the east corridor, and a crude wood cage door closes off the north exit.

An object in this room suppresses magic items for a time.

There is a west path leads to #2

In the east path is a locked door (DC 15), with a key under the mattress in #2, that that leads to #8

There is a north path that leads to #4

In the south path (green) is a wall that seals the path that leads to #10


A cutting block to the west is soiled with old dew, while a low-burning cooking fire to the north heats a pot hanging by chains. A thick soup simmers within it. A rough, winding path leads toward the east. Against the far wall are all manner of surgical tools and knives, as well as bloodstained cloth. The tunnel continues on the other side of the room, meandering gradually to the south and out of sight. To the north and west are two alcoves clogged with frayed notebooks and skeletal remains of humans.

In this room is an event. Heal 4d10 (20) HP but become cursed with 24h Blind if they drink the soup, or take damage equal to 5% of your max HP if they investigate the cutting block as a ghostly presence attacks them with knives, or trigger a wild magic surge at the start of each combat for the next 24h if they ignore both. [Customize]

There is a east path that leads to #5

There is a south path that leads to #3


Water gurgles and rushes from somewhere. Wooden dishware and scattered piles of cards litter the blade-scarred tabletops. This dusty, 35-foot-square room has a high-pitched ceiling that reaches its peak 70 feet above. The wooden rafters are shrouded in moss and leaves. Double doors of wood stand closed to the west. A lit hallway to the north contains a set of wood doors, through which you hear rolling water. An opening at the southern end of the room continues into a tunnel, from which a cold wind moans. A stream spills from a constricted crack to the west and crosses the room, disappearing into a narrow, winding tunnel to the east.

2 Giant Poisonous Snake (CR: 1/4: Monster Manual p. 327), 1 Ogre Bolt Launcher (CR: 2: Mordenkainen's Tome of Foes p. 220), 1 Giant Constrictor Snake (CR: 2: Monster Manual p. 324), 1 Troll (CR: 5: Monster Manual p. 291) (Medium, 560 XP each) [Customize]

There is a west path that leads to #4

There is a east path that leads to #6

There is a north path that leads to #9

There is a south path that leads to #8


A thin ridge on the west side overlooks a stream of lava. A bridge of crystal spans the gap, leading to a large ridge on the west side that follows the course to the south. Vines hang limp in the musty air. Empty steel sconces dot the walls. A gate stands closed to the south. A gate of rough-hewn timber blocks a short passage to the west. Across the bridge is a steel cage with a woman inside.

In this room is a trap. This trap has a cover constructed from material identical to the floor around it that opens vents in the floor and releases scalding steam into the area.

Effect: Targets all creatures within a 10 ft. square area, scalding steam is released which deal 17 (4d10) fire damage and DC 13 CON save or be blind for 1 hour.

Trigger: cover, activates when a creature steps on the false floor and triggers the vents.

Countermeasures: Once the trap is detected with a successful DC 15 Wisdom (Perception) check, an iron spike or similar object can be wedged between the cover and the surrounding floor in such a way as to prevent the cover from opening, thereby making it safe to cross. The cover can also be magically held shut using the arcane lock spell or similar magic.

A strong gust of wind (at least 10mph) will disperse the steam. [Customize]

Rohesia Huckabee, Female Human

Description: This woman is moderately tanned and has just the faintest trace of an accent. She wears dark leathers with embroidery. Sporting a blonde mohawk this woman's hair draws a lot of attention. Her fair skin shows little sign of her aristocratic breeding.

Personality: In the realm of puns, she cannot help herself. She feels obliged to make them. She lacks moral complications. She does what she is told to by employers but not much else. She spends her money on whatever she fancies at the time. Voice: Old thin voice

Rohesia was captured by the minions of the blackguard when she was studying the apparitions of the hot springs. According to her, the surges and cosmic storms have caused this whole area to bleed into another plane, making people in one plane appear as ghostly images in the other plane. Releasing Rohesia will allow her to trace a secret somatic gesture on the wall that opens a portal leading to the other side at the green path.

There is a west path that leads to #5

In the south path is an unlocked door that leads to #7


A simple bed sits in the corner of this room, its four corner posts supporting a yellow canopy trimmed with gold tassels. Spilled alcohol floats in the air here. Veils and curtains of webbing fill the room, making it hard to gauge its width and depth. A fissure spills from a confined crack to the south and crosses the room, disappearing into a cramped, winding tunnel to the west. A short flight of stairs leads up to a grand, iron-bound door. A mossy knight skull is fixed to the wall by a steel spike.

In this room is an event. Entering the fissure will teleport PCs to room #10. [Customize]

In the west path is an unlocked door that leads to #8

There is a north path that leads to #6


A tunnel opens up into a large cavern, roughly 15 by 40 feet with a 45 foot high ceiling covered in stalactites. This room glimmers with a slight phosphorescence. A rough, winding pass leads toward the east. Past the room, the passageway turns back to rough granite and turns to the north, through which you hear a low moan. A lit hallway to the west contains a set of wood doors.

2 Giant Poisonous Snake (CR: 1/4: Monster Manual p. 327), 1 Mouth of Grolantor (CR: 6: Volo's Guide to Monsters p. 149), 1 Shadow Demon (CR: 4: Monster Manual p. 64) (Hard, 700 XP each) [Customize]

In the west path is an unlocked door that leads to #3

There is a east path that leads to #7

There is a north path that leads to #5


The ceiling here rises about 20 feet above, and rubbish and sun-bleached bones covers the floor. A plain wood door is set into the south wall, and light seeps through its cracks. Off to the side, four oversized straw pallets look recently used. On the north wall is written some text.

In the room is a puzzle: You saw me where I never was and where I could not be. And yet within that very place, my face you often see. What am I? A: A reflection.

If the puzzle is solved, a secret compartment in the wall opens where they find 1000 cp, 9000 sp, 1800 gp, 100 pp, Potion of supreme healing,

25 gp valuables (125 gp total): Gold locket with a painted portrait inside, 2 Black velvet mask stitched with silver thread, Copper chalice with silver filigree, and Silver ewer [Customize]

There is a south path that leads to #5


The smell of grease is sharp as you enter this peculiarly organized room. An anvil, tools, and other raw materials fill this room, most of it muddled and all of it clearly coming from outside the lair. A lit hallway to the east contains a set of wood doors, through which you hear wailing. To the side of the exit, there's also a granite desk set with a chair. A pair of leaded glass doors, their panes cracked and broken, stand open between panels of stained glass set into the north wall. The stained glass panels depict giants.

2 Giant Centipede (CR: 1/4: Monster Manual p. 323), 3 Ogre Howdah (CR: 2: Mordenkainen's Tome of Foes p. 221), 1 Verbeeg Longstrider (CR: 5: Icewind Dale: Rime of the Frostmaiden pg 311) (Medium, 650 XP each) [Customize]

Upon entering this room, the sounds of battle can be heard in the distance.

In the east path is an unlocked door that leads to #11

In the north path (green) is a wall that seals the path that leads to #3


A small, arched ceiling caps the 15-foot-wide L-shaped room before you. Dense beams sag overhead from centuries of supporting weight. This room is full of pretty little dolls with alabaster skin and brown hair, some of them dressed beautifully, others plainly. Seated on a large chair against the west wall is a dead hobgoblin. Within this area lie old catacombs, with arched ceilings supported by wide, hollow columns that double as crypts. Small wood gates hang on the stonework, moss clinging to the bars. Frayed green drapes cover the windows of this circular room, and a heavy curtain hangs across an archway to the west.

The dolls in this room offer a game of chance, with the promise of a reward or valuable information. If the PCs agree and win, the dolls laugh and warn the PCs that Amduscia has minions with a frightful aura.

There is a west path that leads to #10

There is a east path that leads to #12


Rotting cots and split bolts are peppered about this large room. A thick fog clings to the floor, which is cloaked in putrid waste. The air is thick with the stench of monsters, and the floor is littered with refuse from the meals and gnawed bones of dubious origin. The far wall is open with a balcony that overlooks the hole-pocked jungle, where below a group of demons clashes in battle with a battalion of soldiers.

4 Rutterkin (CR: 2: Mordenkainen's Tome of Foes p. 136), 1 Blackguard (CR: 8: Volo's Guide to Monsters p. 211) (Deadly, 1,140 XP each) [Customize]

The Blackguard is immune to the Rutterkin's fear. As the battle continues, huge demonic worms emerge from the tunnels in the jungle, devastating the humanoid soldiers in the battle below. If the blackguard Amduscia is killed, his death knell echoes out over the jungle. The demons in the battle below perk up at the noise and flee the fight, flying and clambering towards the dead blackguard. The army of demons reach the blackguard's corpse, fighting with each other as they rip the paladin's soul from his body, and vanish with the soul back to the Abyss.


With the blackguard defeated and the demons satisfied, the springs are declared a protected reserve of unstable planar magic. A group of scholars are tasked with studying it, and attempt to find a way to stop the planar bleeding that afflicts the area. This could lead to a campaign where the PCs try to help and investigate planar disturbances. If the PCs were searching for the artifact, this could lead to a campaign where they try to track down the other pieces and stop those that would misuse it.

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