Rot King’s Sanctum

General Notes

  • I created this conversion using both the DURF and OSR editions of the Rot King’s Sanctum so I could run this as a trial adventure for a potential upcoming Cairn campaign. Yochai Gal was very helpful in improving this conversion.
  • Stats for Melvin are from the Gnome and stats for the Shadow in the Monsters list on the Cairn RPG Website.
  • Stats for Wererat are based on those created by @mapolon on the Cairn RPG Discord

Monsters or NPCs

Corpse Crawler

8 HP, 9 STR, 10 DEX, 8 WIL, tentacles (d8+d8 blast)

  • Critical Damage: target is paralyzed, to be devoured later
  • Can walk on walls, ceilings, etc.


4 HP, 11 STR, 10 DEX, 9 WIL, dagger (d6)

Cultist Guard

4 HP, 1 Armor, 12 STR, 10 DEX, 11 WIL, mace (d8)

Fly Swarm

2 HP, 6 STR, 12 DEX, 11 WIL, bite (d8 blast) detachment

  • Can only be harmed by fire, smoke, or spells.

Melvin (escaping Prisoner)

2 HP, 6 STR, 12 DEX, 10 WIL,

  • Short humanoid with long nose and ears. Live underground or deep in forests.
  • Intelligent tinker, loves messing with any kind of mechanism. Can easily be convinced by the promise of something novel or uncommon.
  • Can understand and communicate with small mammals like moles or squirrels.

Moldy Skeletons

4 HP, 1 Armor, 9 STR, 13 DEX, 10 WIL, rake (d6)

  • Immune to sleep or charm spells
  • When saving for critical damage (regardless of the outcome) there is 3-in-6 chance they release a *cloud of spores* against their assailant.
  • Cloud of Spores: Victim makes a STR save or dies within 6 rounds

Plague Priest

6 HP, 2 Armor, 10 STR, 10 DEX, 11 WIL, mace (d8)

  • Spellbook: Nithis’ Rot: Target’s flesh rots away in one area (1d4 STR loss)

Rat Swarm

4 HP, 6 STR, 12 DEX, 11 WIL, bite (d3) detachment

  • Afraid of fire

Rot King

12 HP, 2 Armor, 15 STR, 10 DEX, 11 WIL, king’s mace (d8)

  • Summon Swarm - 1d4 times per day, the Rot King can release a Fly Swarm from their body.

  • Spells (1x each):

    • Cause Wounds: Target loses d8 STR. Grasp only.
    • Grasp of Yahzahar: Target is grappled by a shadowy hand and held in place for 1d4 rounds. A STR save is required to escape before the spell ends.
    • Swarm Form: Transofmrs into a swarm of bugs, rats or bats.


6 HP, 8 STR, 10 DEX, 14 WIL, draining touch (d6, ignores armor)

  • Incorporeal monsters that look like animated shadows.
  • Unharmed by mundane attacks, sleep or mind control.
  • Critical Damage: Target loses another d4 STR, if reduced to 0 STR, they become a shadow.


Wererat: 6 HP, 11 STR, 14 DEX, 8 WIL, claws (d6+d6), bite (d8)

  • Critical Damage (from a were rat bite) contract lycanthropy.
  • Can summon a rat swarm once per day, the rats arrive in 1d4 rounds.
  • Can appear as either a human or a humanoid rat.
  • Mundane attacks are impaired against a wererat, but weapons made of silver are enhanced.


Room 1

Pressure Plate/Gas Trap

  • Paralyzing gas, WIL save or be paralyzed for 1d4 turns.

Room 4

Mace (d8, see note)

  • Enhanced damage against non-magical opponents

Ring of Spell Turning

  • The wearer can redirect a spell that strikes them back on the caster. Treat this as casting a spell under difficult conditions.

Room 5

Healing Mushroom

  • Mushrooms are deadly (STR save or die). Eating a cooked mushroom heals a point of STR.

Room 8

dripping acid

  • armor exposed to the acid will be reduced by 1 pt
  • creatures exposed to the acid will take 3 pts of damage

Room 10

Potion of Speed

  • Gain a second action each combat round, lasts 1 turn, 1 use

Potion of Smoke Form

  • As the spell, lasts 1 turn

Spellbook of Magic Dampener

  • Nearby magical effects are reduced in potency for one hour.

Spellbook of Fireball

  • Throw an exploding ball of fire that does 1d6 STR damage to an area.

Magic Arrrows

  • +1 damage, 3 usage dots, roll a d6 on use, on a 6 mark a dot

Mithril Mask

  • As the spell Spider Climb.

Sleeping Powder Trap

  • Str Save or fall asleep for 2d4 turns

Room 12

Pool of black liquid

  • Creatures take 1d3 STR per round while touching the liquid. If reduced to 0 STR, they die and turn into black liquid that is drawn into the pool.

Room 14

Potion of Cure Wounds

  • as the spell

Magic Dagger

  • +1 damage

Room 15

d6 scrolls

  1. Sleep
  2. Scry
  3. Magic Damper
  4. Raise Spirit
  5. Deafen
  6. Fireball (see above)

Book of the Will of Nithis

  • WIL save to read. On a fail lose 1d6 WIL. On a success gain 1 WIL (permanent).

Room 16

Lightning Trap

  • Shoots lightning bolts at each creature touching the sarcophagus, dealing 2d6 STR damage.

Rod of Cancellation

  • Drains the magic from one item it touches then crumbles into dust.

Scroll of Lighting Strike

  • Electricity flings from your fingertips doing 1d12 damage (blast) in a line.

Scroll of Animate Object

  • An object obeys your commands as best it can.

Scroll of Elemental Wall

  • You summon a wall of fire, ice, water, or stone up to 20ft wide.