Swamps 101 - Set The Mood
Most swamps lie near a mid-sized body of water, such as a lake or slow moving river. They are often filled with partially stagnant water (salt or fresh) and a wide variety of plant, animal, and insect life.
For this article we will focus on some of the hidden dangers of a swamp, and the unexpected ways the terrain can present new challenges and excitement for your next session.
It's also worth noting you can add a swamp nearly everywhere because they do not have to be big.
A quarter mile square is easily big enough to fit a couple of swamp encounters into. And you can fit something like that in a park, just outside the city walls, or even underground if you set up certain conditions.
A portion of the vegetation within any swamp is in a state of decay, releasing a myriad of various odors, from the pungent odor of mushrooms, to the cloying stench of swamp gas.
These different smells will often distract visitors, and can aggravate allergies or mask the otherwise distinctive smell of sweat or blood from an injured foe. This makes it easier for friend and foe to hide their scent within the murk.
Even at night the humidity of a swamp is unpleasantly high. The air becomes thick, sticky and turgid. Heavy clothing and armor chafe uncomfortably as soggy boots begin to wear blisters on the feet of otherwise seasoned adventurers.
Escaping the environment to make a camp is often difficult. It is hard to find dry land and enough burnable material to make a fire.
Often, an adventurer is better off making temporary shelter within a tree or stringing a makeshift hammock between two saplings to remove themselves from the water and allow their belongings and body time to dry out.
At night during a full moon, the continual drone of insects, often a dull background hum, will rise to a crescendo, interspersed with the chirping of tree frogs and the mating calls of nocturnal predators.
This abundance of noise will make the approach of aggressors much harder to detect, and likely keep the group from getting a full night's rest. This makes the following days' journey much more arduous, and mistakes more commonplace.
Any swamp has a surprising number of stealthy ways to debilitate an adventurer, and a good number that will kill them outright.
Danger #1: Water Borne Illness
Perhaps most hidden of all are the untold quantity of microscopic bacteria, viruses and parasites that fill the water with life.
While normally harmless in small quantities, when exposed to lacerated skin or swallowed (either by accident while drowning, or deliberately through ignorance) these opportunistic parasites quickly infest the hapless host.
And they will bring about all manner of devastating symptoms that can lead to a quick death or reduced function in such an unforgiving environment.
Danger #2: Fungus
Fungus and molds grow readily in the dank, humid, environs of a swamp, and can easily spoil travelers' rations, or eat away at the leather bindings of their armors and dissolve the glue holding their footwear together. Any open sores or abrasions can also quickly become infected with fungus spores, resulting in a nasty painful wound that's not easily treated without magic.
Danger #3: Leeches & Insects
Leeches and biting insects pose a greater danger then simply distracting and annoying travelers, they also drain their blood, and with it their strength. After a day or more of fighting off clouds of mosquitoes and peeling leeches form their legs even the mightiest barbarians will feel drained and tired. Along with losing vital fluids such parasites can also transmit crippling diseases and wasting illnesses.
Danger #4: Hazardous Footing
Within the murky waters lies many rotten logs, partially filled sink holes, and grime encrusted stones. Footing within these areas of a swamp will prove treacherous, and make combat a challenge for friend and foe alike; especially for those wearing heavy armors.
Danger #5: Tree Dwelling Predators
Alligators aren't the only large predators lying in wait for the unsuspecting traveler, tree borne predators like the Panther also lurk in the foliage to drop upon unsuspecting adventures pausing to refill a canteen or answer the call of nature.
Danger #6: Blood Grass
Parasitic blood grass is also rumored to lurk along the edges of many swampy embankments; these foot long blades of grass possess tips akin to hypodermic needles and will readily spear anything that wanders into their midst.
Danger #7: Strangle Vines
Strangle vines are another silent danger, hanging in thick loops from the trees they appear inviting material for lashing together a makeshift raft or tent poles. When touched by warm blooded prey however, these vines loosen themselves to tumble over an adventure, and then constrict powerfully, ensnaring them for slow digestion by excreted fluids from small hidden suckers along the vines length.
Danger #8: Water Vipers
In the gloom of twilight thin water vipers often skim across the watery surface, hunting for small rodents or large insects for their next meal. If disturbed by a passing traveler however, they have been known to lash out with a venomous bite, which leaves the victims extremity swollen and painful for days at a time.
Danger #9: Water Spiders
Under the cover of darkness also dwell house cat sized water spiders; black spindly hunters that skim across the surface in near silence, often swarming larger creatures in groups of a half dozen or more, their nearly painless bite also contains a nasty anticoagulant that makes even a shallow wound bleed profusely.
Danger #10: Stink Moss
Colored a sickly yellow or green, this moss easily blends into its surroundings, coating fallen trees, smooth clearings, and sunken boulders with a soft velvety texture. Unfortunately the moss also contains a foul smelling, greasy liquid that is readily released when stepped upon or crushed. This moss expulsion easily soaks into clothing and permeates skin, making for a lingering stench that will not only nauseate the victim, but attract the attention of insects and carrion eaters.
A good swamp is teeming with encounter possibles, here's a few that can be dropped into most any swamp adventure.
Encounter #1: Dead Man Climbing
Who: A corpse perched part way up a dead tree covered in rotted clothes with a half torn backpack dangling from one bony arm.
What: Investigation reveals inside the rotten pack are mostly rags and a few tarnished coins, along with a vial of a faintly glowing elixir, the label long since faded into obscurity.
(The potion could be anything from a cure disease tincture to a topical insect repellent or flammable oil.)
When: Most groups will spend several minutes retrieving the corpse and discussing and analyzing the bottle's mysterious contents. That makes this a great encounter to use when you need to stall for time to prepare the next piece of your adventure or to break up the pacing with some inter-party interaction.
Where: The tree forms the centerpiece of an isolated island that's just large enough to gather around the base of the tree. Thick undergrowth obscures the slippery roots of the trunk and an abandoned bird nest.
Encounter #2: Bird in a Bush
Who: A large bird with a broken wing struggles to remain upright. Nearby, a large crocodile sneaks up and readies itself to make a meal of the injured animal.
What: The bird will befriend the PCs if saved. The croc attacks the nearest thing a few seconds after being disturbed.
When: A short encounter that can provide the group with an unexpected animal friend, and give a feeling of life in the swamp occurring independently of the characters' actions. It works best as a way to speed up the pacing with a brief spot of excitement.
Where: In a stand of matted reeds near a deep channel of brackish water.
Encounter #3: Gas Attack
Who: A small clearing (with a foul smell) looks to be the result of a sudden explosion several days ago. Charred branches and burnt swamp grass litter the large circle. The remains of a small animal lay at the center.
What: The damage is the result of a swamp gas explosion, and any open flame could easily trigger another such eruption.
When: This encounter could be used when the party stops to rest or make camp, since part of the fun from this one is the secondary pop when the group's campfire ignites the second pocket of gas.
Where: A dense area on one of the few islands that sport solid enough ground for a brief rest stop.
Encounter #4: Mini Map
Who: A large decayed tree looks to have a crude map carved in its side. A rusty knife lays half-buried in the mud at the tree's roots. Unfortunately, the stump is surrounded by blood grass, and nearby tracks hint at this being the hunting grounds of a sizeable alligator as well.
What: The map could be a quest or nothing more than a crude warning about a nest of swamp vipers a little ways ahead, as the fading scratches could be easily misinterpreted.
When: Another good encounter to use when you need time to prep the next piece of the adventure since clearing out the blood grass and deciphering the map will take most PC groups 10-20 minutes.
Where: The stump sits to the side of a clearing, visible to passersby. The dull glint of the rusting knife helps draw attention to the location.
Encounter #5: Boar in a Bog
Who: The panicked bleating and grunting of a large animal echoes from nearby. Closer inspection reveals a dire warthog, mired in a sink hole and struggling in vain to free itself.
What: If rescued, the creature will be exhausted and easily slain. Else it will lumber off after several minutes if given the chance, leading the party to a well-used boar run winding amid the marshy areas of the swamp.
When: A good encounter to use when the group is running low on supplies, since the temptation to kill the boar for dinner will be high, but properly preparing the meat will prove challenging in the damp swamp environment.
Where: Behind thick overgrown ferns and mossy cattails out of the PCs' view. Those who charge the source of the noise could also become trapped in the sink hole.
Encounter #6: Storm Break
Who: A peal of thunder heralds an impending storm, the sudden breeze a welcome relief in the humidity of the swamp. Unfortunately, the high winds and downpour will make continued navigation difficult, and many of the swamp's predators will be using the plentiful cover for their own protection.
What: The storm will arrive in under 10 minutes, and many of the local animals are already scurrying about to seek shelter, resulting in a small wave of chaos as rodents, reptiles and birds dart about.
When: A good encounter to use as prelude to something more significant, or to prod the PCs into action if the pacing slows due to deliberation and uncertainty.
Where: Virtually anywhere in the swamps, especially an area with multiple options for shelter a short dash away.
Encounter #7: Will-o'-the-wisp
Who: The adventurers see a strange flickering light hovering over the swamp a short distance from their camp. It seems to be beckoning to them, as if it wishes to lead them to an as yet undiscovered secret of the marsh.
What: The light is a will-o'-the-wisp, and if followed will lead the pursuers to a run down mud hut - that of an old hermit who has long since passed away.
Inside the hut are a few personal belongings, hunting spears and hand-written a diary detailing the hermit's life and several points of interest within the swamp.
When: A good encounter to spring on a PC during guard duty, or to tempt the curious PC of the group with a tantalizing mystery.
Where: Shortly after dark, a little ways off from the party's camp, where the lights can be seen between cattails and over-grown fronds.
Encounter #8: Fishing Pool
Who: In a nearby pool, the water churns as several large fish swirl about in a complex mating dance. The water froths loud enough to drown out the sounds of nearby insects and birds, as well as draw the interest of hungry predators.
What: The fish are large and edible, but taking the time to catch them will result in an inquisitive alligator arriving to interrupt the party.
When: A quick drop-in that can be used at any time, but best saved for when the party's food supplies are beginning to dwindle.
Where: A deep pool of water, several feet off the party's chosen path, surrounded by fallen logs to make a natural well appearance.
Encounter #9: Spider Ambush
Who: A soft chittering awakens one of the sleeping party members, who notices to their horror a nearby companion is covered in predatory water spiders. The melon-sized creatures position themselves in preparation for a feast.
What: The spiders will attack the sleeping person within a few seconds, or if disturbed sooner, spread out to assault any who disturb them.
When: A great encounter to highlight the nocturnal dangers of the swamp and provide for a challenging combat scenario given the majority of the PCs will likely be sleeping without their armor on.
Where: Wherever the party makes camp, ideally near a large body of water or marshy area with plenty of narrow water channels.
Encounter #10: Missing Son
Who: Near the edges of the swamp a male voice can be heard, yelling the name "Thomas" repeatedly. Investigation reveals a farmer from nearby hunting for his 13 year old son who had gone fishing earlier that morning.
What: If the characters assist the farmer in finding his boy they will earn a free night's lodging and the goodwill of the farmer and his community.
When: Best used either near the beginning or end of the PCs' foray into the swamp. Can work well as a springboard to take the party deeper into the fen than they would otherwise have reason to travel.
Where: On the edge of the swamp, where the houses of a nearby community beginning to peter out and the wilderness is reasserting its domination.
Here are a few great resources (with links) to help with getting a better feel for the dangers of a swamp, and how to best portray one within your game.
(Note: Most of the TV/movie titles can be found on Netflix instant streaming)
Man vs. Wild
specifically the Panama and Florida Everglades episodes, which cover the Mangrove and Everglade swamps.
A reality TV show portraying the day-to-day activities for several Cajuns living in the Atchafalaya River Basin swamp in Louisiana.
A superhero style action movie set in the Louisiana Bayous.
Streams of Silver by R.A Salvatore
(book #2 of the Icewind Dale Trilogy)
While swamps aren't the main feature of the storyline, there is a memorable multi chapter adventure through a grueling swamp, complete with trolls and a giant purple worm.
Son of Spellsinger by Alan Dean Foster
It features an interesting fungus based swamp during the first few opening chapters of the novel that stick out as one of the more unusual takes on a "swamp" I've seen so far.
The Forest of Peldain by Barrington J Bailey
While not entirely a swamp based adventure novel, many of the fantastic predatory plants featured in the book (such as Mangrab Trees and Cage Tigers) can be easily adapted for a swamp environment.
Bits of the Wilderness: Into the Swamps
Over 180 different descriptions and plot hooks for swamp settings and adventures, without a doubt a must have for any GM planning to run an extended session in a swamp.
E-Adventure Tiles: Swamps
16 different tile sets to use for marshlands and swamps with your favorite minis.
E-Adventure Tiles: Swamps: Shorelines
An expanded set of tiles for minis, features the shore line between swamps and the surrounding environments.
Bringing It All Together
By combining the hidden dangers of swamps, with the normal excitement of overland travel, you can easily create a memorable set of adventures that will leave your players talking about the perils of marshy bogs long after they have been left behind.
Like any other wilderness environment, part of the struggle isn't just navigating the terrain, but surviving (and overcoming) the unique challenges this land has to offer, and hopefully walk away a little bit wiser for the ordeal. With a little effort it's easy to to muck around with swamps in your games.