Sunday, October 4, 2026

Dungeon: Flaming Swamp Crypt

It's Skeleton Season. Here's a dungeon. Written for Cairn, but easily adaptable for an OSR of your liking. 

Trumpeters of Death (1526) by Hans Holbein the Younger


Background: In ages past, a great cabal of Necromancers fled the heartland of civilization to the fringes and borderlands of the north. They infested the abandoned crypts and tombs of long-forgotten civilization, desecrating the dead to practice their art. This is one such tomb. 

The Rosesword Knights crusaded against the evil of the Necromancers. Many knights fell in this purge, and their arms are often left as mementos of battle. They slew countless occultists, and sealed off their tombs. But you can never truly kill a Necromancer.  

Hooks: Recover lost weapons of the Rosesword Knights. Recover lost knowledge of the Necromancers. 

Locale: located in a great swamp, sunken down in the mire. The Sealed Door is only accessible by descending a sinkhole. 

 

101 - Sealed Door. Briar vines seal the door, easily burned away. In the center is an inscribed seal: "I, Pellinore, have slain the Necromancer and bound his evil within. No mortal should enter."

 102 Skull. A silvery skull is being licked clean by a toad. Swamp water drips from the stone ceiling. 

  • Rorgis, the Skull - a chatty, trouble maker undead. Will feign being inanimate and try to surprise someone at an opportune time as a prank. Just wants his body back (107) so he can do stand up comedy

103 Entrance.  Stinks, but no worse than the swamp outside. Broken bones scattered with some burial shelves on the northern wall. Grave poppies bloom amongst the bones

  • Burial shelves - truly ancient bones. Some (1d4) grave goods (10 gp)
  • Grave poppies - can be brewed into sleep potions or to empower spirits. 

104 Slide. Wet hallway, slippery from moisture. When 20 lbs or more weighs down the northern corner, the floor falls away, sliding whoever triggers the trap to 205. 

105 Lilypads. Most of the stone floor has fallen away into the swamp water below. Big lily pads have grown through the gaps, large enough for someone to stand on. Something gleams from an elevated landing to the south (111). 

  • Lilypads - requires a DEX check. 3 successful checks needed to reach 111. On a failure, there's a 4-in-6 chance to land in 203; otherwise land in this room. 

106 Bridgeway. A narrow stone walkway winds over a pool of fetid water (204), flanked by two alcoves. Statues line the alcoves. 

  • 2 Shield Skeletons stand on the bridge, preventing passage. (As Skeletons with 2 armor, and 1d4 Shield bash instead of sword)
  • Bow Skeletons - one on each ledge. (As Skeletons)
  • Statues - Shepard figures. 2 on the western side and 1 on the eastern side have emerald eyes (50 gp each)

107 Swords.  A headless skeleton bumps into the walls, kicking loose, rusted swords. A banner of roses covers the eastern wall, and a relief is carved into the western wall. 

  • Skeleton body - belongs to Rorgis. Under his control, even when separated.
  • Weapons - arms of the Rosesword Knights. A Halberd maintains its edge. (Enchanted. Rose blossoms on its blade. If swung rapidly overhead, petals will cover a small area. WIL save or be poisoned by the rose petals. [Poisoned: Gain Fatigue and have disadvantage on rolls until cleared)
  • Banner - depicts the knights, triumphant. Covers a tunnel 15 ft up on the wall. 
  • Relief - A Shepard guiding a flock through a wood. The Shepard is cut-out secret door to the eastern alcove in 106.

107A Alcove. A horribly twisted skeleton, its bones pockmarked, crowned with a silver band. It still clutches a grimoire.

  • Silver Band - prevents dead from rising. If removed, the Necromancer will animate. 
  • Grimoire - Spider climb (Warden's Guide)

108 Cookin'. A pile of black bones rest in a large basin filled with oil. A key shines at the bottom. Burial niches line the shelves. 

  • Key - to the cage in 206. Grabbing it disturbs the skeletons. 
  • Black-bone Skeletons - 6 total, but clamber out of the oil basin in waves (3, then 2, then 1). They will try to light themselves on fire and hug foes. (Stats as Skeletons but with extremely flammable limbs)
  • Niche - A rotting hand tattooed with twin spiral circles, the symbol of Necromancers. Cursed item. Causes nearby dead to animate. Removing it will prevent more dead from rising.  

109 Dead Door. A grinning skull set above an ornate gravestone with a handle. Inscribed above: "This door cannot be opened by the living.

  • 2d6 necrotic damage if a mortal tries to open the door. 
  • Only openable by a non-living thing (skeleton, rope, etc) 

 110 Lab. Upturned tables, desk, and arcane baubles, most smashed and burned. A single rose-like flower blooms in the ground. 

  • Flower - Contains the soul of a Rosesword Knight (Syr Allen)
  • Loot - A grimoire labeled "Transmute Scungler," the interior pages are missing. An imp in a jar of formaldehyde (200 gp)
    • Transmute Scungler: Needs to be researched. Transforms a humanoid corpse into a 4-legged rotund-plant. It can carry items efficiently into its center pod, but is often hunrgy.  

111 Landing. A bulbous, insect covered corpse lies in front of a huge door, barred with a hefty wood bar.

  • Corpse - features ruined. Clutches a Scroll of Bloodflame Art and 120 gp.  
    • Bloodflame Art. You can magically cause any bloodied weapon to catch on fire.  
  • Door - requires 30 combined STR to lift the bar. Opens to the bottom of the swamp. If opened, swamp water will start to flood in, quickly filling 203 & 105 and slowly filling the rest of the crypt.

Swamp Rose (1887) by Isaac Sprague

201 Gas. Reeks horribly of swamp gas. Lit torches flicker blue before quickly igniting. Visible to 202.

202 Flaming Bone Skeletons stand around. They'll rush into 201 and swing their flaming swords around to cause more chaos. (Skeletons with rusted flaming swords (d6 + d6))

203 Lily pad pool. A pool, filled with stagnant swamp water, and encircled with small walkway. The door south is bared and chained (requires 2 people to open)

  • Swamp water - sickening. STR save each round in the water or gain 1 fatigue. 

204 Filthy Swamp Water. A smashed stone statue sticks out of this stinking soup. Skeletons from 106 can fire down;  swamp water same effect as 203.  There's a small sewer tunnel, hidden, that leads to 205. 

205 Another Pool. Undead crocodiles hid in this putrid pool. The very air reeks, and flies buzz around the top of a small mound of dirt. 

  • Crocodile - Stats as Boar.  
  • Dirt - buried within is a rotting hand tattooed with twin spirals. (See 108). 
  • Air - gag induces. Speaking or casting spells requires a STR save. 

206 Treasure & Toad. Atop a pile of gold (500 gp), a huge undead frog "sleeps." 

  •  Frog monster - three giant frogs stitched together and stacked. Three tongues loll out of three mouths. Stats as Ogre with Critical Damage: Target is swallowed. 

207 Basement Landing. Burial niches in the walls (1d4 grave goods worth 10 gp), A winding staircase leads to the Dead Door in 109, which is easily opened from this side.  

Amazon.com: LYSINK Skeleton Frog Halloween Decor Model, Plastic Animal Skull  Frog Bone Art Ornaments, White, 9.2cmx8.2cmx6.3cm : Home & Kitchen 

 Appendix N

 

 

Dungeon: Flaming Swamp Crypt

It's Skeleton Season. Here's a dungeon. Written for Cairn, but easily adaptable for an OSR of your liking.  Background: In ages past...