Eldritch Swamp

Swamp
Alexander Hatley, CC BY 2.0, Wikimedia Commons

Something from outside the world has touched this land. Angles are wrong, the stars sit in the wrong places, and the animals that remain have too many eyes or too few. Those who stay too long start to hear a voice under every other sound. Flooded forest where trees stand in dark, still water. Paths vanish, mud holds the feet, insects swarm, and boats go where legs cannot.

Hear it

For the table

Ground
hard going, about 10 km a day on foot
Water
plentiful
Foraging
poor

Hazards

  • Sucking mud. Firm-looking ground opens onto deep mud or peat. Alone and laden, a traveller can be held until the water rises or the cold comes.
  • Fevers. Warm stagnant water breeds the fevers that emptied whole expeditions before anyone knew the mosquito carried them.
  • Biting insects. In the warm season, clouds of mosquitoes and flies bite day and night. Sleep and tempers wear thin.
  • Getting lost. Under the trees, in the dunes or in the dark, every direction looks alike. Without a guide or a sure landmark, a party walks in circles.
  • Wrong angles. Paths bend back on themselves and distances will not hold. A ridge seen at noon is no closer by evening.
  • Whispers from beyond. At night a voice speaks just below hearing, in a language no one ever learned and everyone almost understands.
  • The glimpse. Sometimes, at the edge of the light, something shows itself for a heartbeat: too large, too many limbs, gone at once.

D&D 5e

Plays as
swamp, slow pace at most
Checks
forage: Survival DC 10 · find the way: DC 15 · search: DC 20
Creatures are spotted at
2d8 × 10 ft
  • Wrong angles. (House rule) Each day the guide makes a DC 14 Wisdom (Survival) check. On a failure the party covers only half the day’s distance, however long it walks.
  • Whispers from beyond. A creature that keeps watch alone makes a DC 15 Wisdom save, taking 3d6 Psychic damage on a failure, or half as much on a success.
  • The glimpse. Whoever sees it makes a DC 15 Wisdom save or is Frightened, repeating the save at the end of each of its turns.

This work includes material from the System Reference Document 5.2.1 ("SRD 5.2.1") by Wizards of the Coast LLC, available at https://www.dndbeyond.com/srd. The SRD 5.2.1 is licensed under the Creative Commons Attribution 4.0 International License, available at https://creativecommons.org/licenses/by/4.0/legalcode.

Pathfinder Second Edition

Plays as (Pathfinder Second Edition)
swamp, greater difficult terrain, about 11 km a day at Speed 25
Checks
Subsist: Survival DC 15 · Sense Direction: Survival DC 20
Random encounters
flat check DC 14 each day
  • Sucking mud. Quicksand (GM Core p. 107): a hidden patch about 5 m wide (Stealth +12; Survival DC 18 to spot by disturbing it). Stepping in sinks a traveller to the waist, then one step each round (neck, then under); Athletics DC 20 climbs back a step, and allies can pull with Athletics DC 20.
  • Getting lost. Sense Direction (Player Core p. 246): a Survival check once a day, –2 without a compass; DC 15 in ordinary wild land, 20 in deep forest or underground, 30 in a featureless desert. Getting lost has no fixed penalty: the GM decides where the party ends up.

This product is licensed under the ORC License located at the Library of Congress at TX 9-307-067 and available online at various locations including paizo.com/orclicense, azoralaw.com/orclicense, and others. All warranties are disclaimed as set forth therein. Attribution: this rules layer is based on the following Licensed Material: Pathfinder Player Core © 2023 Paizo Inc., Designed by Logan Bonner, Jason Bulmahn, Stephen Radney-MacFarland, and Mark Seifter. Authors: Alexander Augunas, Kate Baker, Logan Bonner, Jason Bulmahn, Carlos Cabrera, Calder CaDavid, James Case, Eleanor Ferron, Steven Hammond, Joan Hong, Vanessa Hoskins, James Jacobs, Jenny Jarzabski, Erik Keith, Dustin Knight, Lyz Liddell, Luis Loza, Patchen Mortimer, Dennis Muldoon, Stephen Radney-MacFarland, Mikhail Rekun, David N. Ross, Michael Sayre, Mark Seifter, Kendra Leigh Speedling, Mark Thompson, Clark Valentine, Andrew White, Landon Winkler, and Linda Zayas-Palmer; Pathfinder GM Core © 2023 Paizo Inc., Designed by Logan Bonner and Mark Seifter. Authors: Amirali Attar Olyaee, Logan Bonner, Creighton Broadhurst, Jason Bulmahn, James Case, Jesse Decker, Eleanor Ferron, Fabby Garza Marroquín, Jaym Gates, Matthew Goetz, James Jacobs, Brian R. James, Jenny Jarzabski, Dustin Knight, Jason LeMaitre, Lyz Liddell, Luis Loza, Ron Lundeen, Stephen Radney-MacFarland, David N. Ross, Michael Sayre, Mark Seifter, Owen K.C. Stephens, Amber Stewart, Clark Valentine, Landon Winkler, and Linda Zayas-Palmer; Pathfinder Monster Core © 2024 Paizo Inc., Authors: Alexander Augunas, Dennis Baker, Kate Baker, Joshua Birdsong, Joseph Blomquist, Logan Bonner, Jason Bulmahn, James Case, John Compton, Paris Crenshaw, Adam Daigle, Darrin Drader, Brian Duckwitz, Robert N. Emerson, Scott Fernandez, Eleanor Ferron, Leo Glass, Matthew Goodall, BJ Hensley, Thurston Hillman, Vanessa Hoskins, James Jacobs, Jenny Jarzabski, Miko Kallio, Jason Keeley, Jeff Lee, Lyz Liddell, Luis Loza, Ron Lundeen, Robert G. McCreary, Philippe-Antoine Menard, Jacob W. Michaels, Dave Nelson, Jason Nelson, Tim Nightengale, Stephen Radney-MacFarland, Mikhail Rekun, Patrick Renie, Alex Riggs, David N. Ross, Michael Sayre, Mark Seifter, Chris S. Sims, Amber Stewart, Jeffrey Swank, William Thompson, Jason Tondro, Clark Valentine, Landon Winkler, Tonya Woldridge, and Linda Zayas-Palmer. If you use our Licensed Material in your own published work, please credit us as follows: Biomes, Pathfinder Second Edition rules layer © 2026 Michael Ghelfi. Reserved Material: the names of Biomes and its catalogues, its descriptions, sounds, art and code. Pathfinder is a registered trademark of Paizo Inc.; this site is not published, endorsed, or specifically approved by Paizo Inc.

Adventure hooks

  1. A surveyor hired to map the land keeps drawing paths that close on themselves in fewer steps than it took to walk them. His guild thinks he drinks, and he wants a sober witness who can count to sign his maps.
  2. A shepherd’s daughter has begun answering questions a moment before anyone asks them, and her mother begs the party to cure her before the priest hears of it. The girl is not possessed: she is translating the voice under every sound, and all it asks is to be left alone.
  3. A scholar from the city pays a silver piece to anyone who can hum him the voice beneath the sounds. By now the whole tavern hums the same tune without noticing, and the scholar has stopped humming it, which frightens him far more.
  4. A hunting party came back with one man more than it left with. Each hunter swears he knows the newcomer, and each names a different person; he is kind, helpful and tireless, and nobody has ever seen him blink.
  5. A ferryman poles travellers through the flooded forest and asks no money, only a story. He has stopped his boat halfway across, because the story he has just heard was about him.
  6. A healer who lives on stilts in the swamp sells remedies to the town, and the council has decided she poisoned the mayor. She wants the real poisoner found, and she pays in leeches, very good ones.
  7. Loggers float cypress trunks out of the swamp on the high water. One raft came out with a coffin lashed to it, well roped, the foreman’s own name carved into the lid.
  8. An alligator the town calls the Bishop has swallowed half of the tax collector’s boat, strongbox and all. The town wants the strongbox back, and is in no hurry about the tax collector.

What grows here

  • Bald Cypress (tree). A deciduous conifer of 10 to 40 m whose feathery needles turn copper-red and fall each autumn, its trunk ringed by woody knees rising from the roots. It once dominated the swamps and river bottoms of the southeastern United States and can live over 2,000 years. Its water-resistant wood was used for canoes, coffins and shingles. Gives: Bald Cypress Wood.
  • Papyrus (sedge). A tall sedge of 4 to 5 m whose triangular stems end in a green mop of thread-like rays. It forms vast pure stands in the swamps and on the lake and river margins of tropical Africa, and in deep water floats in mats that make the sudd. The Egyptians made paper, boats, mats and rope from it. Gives: Papyrus Stem, Papyrus Rhizome.

Animals

Kept here

Creatures

Also met here

This work includes material from the System Reference Document 5.2.1 ("SRD 5.2.1") by Wizards of the Coast LLC, available at https://www.dndbeyond.com/srd. The SRD 5.2.1 is licensed under the Creative Commons Attribution 4.0 International License, available at https://creativecommons.org/licenses/by/4.0/legalcode.

To gather

Nothic Iris, Froghemoth Tongue, Bald Cypress Wood, Crocodile Glands, Eurasian Beaver Pelt, Eurasian Otter Pelt, Horsehair, Moose Hide, Nile Crocodile Egg, Papyrus Rhizome, Papyrus Stem, Buffalo Hide, Buffalo Milk, Wild Boar Bristles, Willow Bark, Eurasian Beaver Castoreum, Green Anaconda Fat, Hippopotamus Hide, Hippopotamus Ivory, Jaguar Fang, Jaguar Pelt, Nile Crocodile Hide, Tiger Bone, Tiger Pelt, Beetle Wing, Frog Lung, Giant Mosquito Wing, Orchid Flower, Snake Venom, Wolf Aloe Leaf, Grung Venom, Hag Index Finger, Pitcher Plant Nectar, Sundew Tentacle, Will-o'-Wisp Spark, Concentrated Venom, Corpse Flower Petal, Electric Eel Gland, Ghost Orchid, Hag Brain, Sea Hag Gill, Troll Bone Marrow, Will-o'-Wisp Trail, Catoblepas Eye Gland, Hag Moldy Heart, Naga Perfect Scale, Wandering Mound Mother Root, Adult Dragon Tonsils, Dragon Tongue, Hydra Bile, Witch's Eye

To fish

Bog Lungfish, Bullfrog, Freshwater Crayfish, Mud Catfish, Swamp Leech Cluster, Myconid Raft, Reed Otter, River Pike, Electric Eel, Marsh Crocodile, Sorrow Pike, Sunken Reliquary, Black Lotus Bloom

The same milieu, otherwise

Swamp, Cursed Swamp, Corrupted Swamp, Fungal Swamp, Dead Swamp, Primeval Swamp, Frozen Swamp, Toxic Swamp

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