d100 Acanthus’s Truths About Mushrooms

Neither plant nor animal, and with more in common genetically with humans than potatoes, fungi are mysterious creatures in our own landscape, let alone a gaming world. They cover vast areas known to be the size of towns and can expand even further. However, less than 10% of species have been identified and the features of many of the known varieties are not clear.

In the Underworld, mushrooms and fungi are all pervasive across the upper reaches, while in the hidden depths they may well be the only living thing, untouched for countless millions of years. Here, they will have evolved in ways we can only imagine. Indeed, many dark cities and their societies have “punishment gates” that send the guilty hundreds of miles towards the center of Aventyr, to regions from which nothing is known to have returned.

Fungi forests are like surface woodlands, full of similar or comparable creatures. But they developed long before plants, well over half-a-billion years before them, and so have a greater impact on all living creatures, both benign and malignant. Many of these effects are useful for gaming purposes. Over time, communities become entirely reliant on the species of fungi their settlement is built around, using them for essentials like food, medicine in the form of penicillin, clothing, building materials, and poisons for hunting and defense.

Below are 100 hooks you can use to help expand encounters with mushrooms and fungi. Although some sound bizarre, many are based on what is currently known or being tested about species on Earth, while others are expansions of facts combined with gaming lore. We will let you to decide which is which!

d100 Truths about Mushrooms

1. At least one species of fungus grows in every known environment: from extreme heat to cold; tempestuous open skies to unmoving rocky depths; dangerous concentrations of salts, both acid and alkali; the crushing pressure of oceans to the radiation of space.
2. Within the Underworld, most is known about species of fungi that are synanthropic, i.e., they exist in or close to humanoid settlements. As there are very few settled areas of the Underworld, little is known about remote fungi species.
3. As 90% of fungi deep in the Underworld are unknown species, creatures that eat them often change their type, becoming part of the hidden “dark taxa” that thrives there.
4. At present, “dark taxa” sages and clerics have been able to confirm just four true fungi deities – Chytreed, Fhungar, Hyphyla, and Mykiis or Myciita – although these are considered the current incarnations of truly ancient divine beings.
5. At present, “dark taxa” sages and clerics suspect that sentient or “higher” fungi are watched over by a demi-deity named Dikariyan, a being that monitors and promotes the development of both intelligence and wisdom within these creatures.
6. If something enters any huge honey-type fungus patch – which can be hundreds of square miles in area – its speed is reduced by a quarter because of the sticky, spongy nature of the floor.
7. Some mushroom patches, weighing many thousands of pounds, flow like sand around the legs of anything walking on them and eventually trap the target creature.
8. Some fungi patches hide deep crevasses and valleys in the Underworld. The mushrooms then open slopes in the growth so travelers become engulfed by waves of fungi.
9. Many fungi glow at certain times, often green but other colors too. This light can be bright enough to disrupt sleep.
10. Some fungus flash vividly if disturbed, whether being picked or even pushed against. The pulse of color is disorientating, similar in nature to a hypnotic pattern
11. Defensive mushrooms that glow like moonlight are used by aggressive species of poisonous fungi and a variety of Underworld creatures to light paths that lead to traps and lairs. The aggressors then feed the defenders.
12. Some fungi glow at frequencies outside the visible spectrum. Ultraviolet glows affect some creatures and burns humanoids like a divine favor Infrared glows allow some creatures to track others, while it heats up humanoids.
13. Semi-intelligent species of glowing fungi that live mutualistically often grow so that any light produced by one mushroom means another casts deep shadows around it. This makes lighting one condition worse than it first appears, e.g., “bright” is “dim.”
14. Most toxic fungi choose between living a vibrant, enticingly visible existence or a hidden and disguised crypsis lifestyle. Underworld humanoids often refer to them as “bard banes” or “assassin afflictions” when talking about them.
15. Some fungi feed on oil of all types. These species move towards camps using oil lamps and drain vessels holding the liquid.
16. Some fungi are attracted to the oils and grease given off by creatures. Spores quickly flow towards such creatures and cover them, looking as if they have been affected by radiant or necrotic damage depending on the species.
17. Some fungi live symbiotically with creatures that produce mucus, ingesting the slime and cleaning the host, which is often smothered in the parasitic mushroom.
18. Some species of mushroom exude an anesthetic-like enzyme that renders flesh senseless as a creature sleeps. This allows the mushroom to wrap mycelia around the victim and absorb it.
19. Some species of mushroom can secrete an acid-like enzyme that dissolves living wood and plant life to create food for itself.
20. Some species of mushroom have developed the ability to vibrate at frequencies that scare away predatory insects and spiders.
21. Some species of mushroom exist entirely on rotted material to the extent that patches of such fungi induce the same effects as entering a charnel house.
22. Some species of mushroom emanate a substance that acts like an acidic rusting agent and rapidly dissolves metal if they are struck by such a weapon or tool.
23. Some species of mushroom discharge an acidic enzyme that softens rock and bone, making it easier for the fungi to burrow into both materials.
24. Where the Underworld meets the Deep Frontier, a few species of fungi grow on solely radiation. These radiotrophic fungi thrive where radiation levels are about 500 time greater than usual and constantly deliver a mixture of necrotic and radiant damage.
25. Some species of fungi grow slowly as they are carbon assimilators. However, if an air-breathing creature lingers and exhales cardon dioxide, these mushrooms increase in size by 20% in a few minutes, often blocking passages or caves and trapping the victim.
26. While all mushrooms eventually die and decompose into liquids, some species of fungi have a transitional phase where they live as a slime, ooze, or jelly before they rot completely away. They carry spores within themselves when they exist this way.
27. Many poisonous fungi use undead, especially zombies, ghouls and ghasts, to move around the Underworld, feeding on the rotting flesh.
28. Some species of fungi that create undead creatures turn them into zombies-skeleton-like hybrids, with the best features of both. This only seems to occur if the base creature is an insect with a hard shell of some kind, such as ants, cockroaches, wasps and so on.
29. When someone tries to identify a mushroom, they are at a disadvantage because so many species have not been discovered. However, there are many similarities across species, so assumptions may prove correct.
30. The features of many fungi are unknown because they can take on one or more of the abilities of their last victim or meal at a low level. As GM you can chose such abilities.
31. Unless an enquirer has a specific link to a deity concerned with fungi, 90% of questions asked using divination spells fail to provide a conclusive or accurate answer, leading to confusion.
32. Unless someone has a specific affinity with fungi, or has lived in a fungi forest much of their life, dealings with these organisms are at a disadvantage, leading to errors.
33. For every mile from a sizeable Underworld settlement that a fungi forest is found, there is a cumulative 1% chance that the species that make up the forest are no longer plants. Instead, they are a separate taxonomy, requiring different magic to deal with.
34. When mushrooms get a large amount of their food from the bodies of creatures with blood there is a cumulative 1% chance per year that they become those creatures for the purposes of spells and items that affect them.
35. Druids that spend extended periods living exclusively in fungi forests cast spells that usually affect plants at an advantage when mushrooms are the focus but at a disadvantage for all other plants.
36. Druids that spend extended periods living exclusively in fungi forests use tiny mushrooms instead of mistletoe as the spell component when casting, e.g.,
37. Druids that spend extended periods living exclusively in fungi forests cast hallucinatory terrain so that checks made to disbelieve it are at a disadvantage and cast mirage arcane so that even truesight cannot see through it.
38. Druids that spend extended periods living exclusively in fungi forests uses mycelia rather than weeds and vines when they cast entangle. This has the advantage of the roots spreading news of the attack across the entire system.
39. Druids that spend extended periods living exclusively in fungi forests add the thick mulch floor of their homes to the list of materials affected when they cast move earth.
40. A single barefoot step in a fungus forest will pick up the spores of 100-or-more species of mushroom, but this may be a gross underestimation.
41. The smaller the mushroom, the more likely it is to have tens of thousands of tiny spores that smother potential homes, grow rapidly where they land, but die back quickly.
42. The bigger the mushroom, the more likely it is to have hundreds of larger spores that search for the ideal conditions in which to grow, even following host creatures.
43. When beasts, dragons or similar become hosts, the fungi quickly take hold in hair follicles, where scales meet skin, and other deep-rooted places. Attacking the host creature releases spores.
44. When giants, goblinoids or humanoids or similar become hosts, the mushrooms grow in any warm, wet crevasse or crack they can find, even glued to the roof of mouths. Here the fungi feed on skin, saliva and sweat.
45. When fungi go through three growth cycles with a living creature as a host, they can become a variant of the host, behaving as a type of “sub-beast” or hybrid.
46. The outer skin of some species of poisonous fungi is used as funeral shrouds because it blends with the body and rises as a zombie or ghoul mushroom with features of both.
47. Some fungi produce spores that work their way into the brains of insects and spiders, eventually taking over control of the host creature before bursting through the skull.
48. Some huge mushrooms attack humanoids and other warm-blooded creatures with thin threads of mycelia that puncture the skin and take over the nervous system of the host.
49. Some fungi that are acid-resistant establish patches of growth with the stomach of living creatures and eat some of the food the host takes in before it can be digested.
50. Some fungi take control of specific muscles in living creatures and dictate when and how they work, which can be a boon or a bane depending on whether the mushroom is being attacked.
51. Some of the smallest fungi work their way to the insides of organs of living creatures and begin to affect their functions in an everyday manner that is based on what the host drinks on a regular basis.
52. Some of the smallest mushrooms send mycelia into the brains of hosts and induce madness. Traditional short-term madnesses become long-term, while long-term variants become indefinite.
53. The spores of some fungi create powerful hallucinations, replicating spells such as dream, mislead or programmed illusion, and it is rumored even weird. Ingesting the skin and juice of these fungi is said to have a similar effect.
54. Many medium-sized and larger fungi use their gills or pores to manipulate air currents and create disorientating murmurs throughout the caverns in which they dwell.
55. Mushrooms that grow in the kidneys and liver stop them from dealing with waste product so the host eventually poisons themself.
56. Mushrooms that use basic poisons induce the following: jaundice, weakness, dizziness, sickness, incapacity. Stronger variants can go on to kill the target.
57. Mushrooms that use stronger poisons that take longer to act affect healing (even magical healing) and destroy reproducing cells one-by-one until the host dies.
58. Saves against the most poisonous fungi, such as Dapperlings, Deathcaps, Destroying Angels and Webcaps, are related to their size, i.e., “small” mushrooms are “easy” to resist, “gargantuan” specimens are “nearly impossible,” and so on.
59. Some species of naturally non-toxic fungi absorb dangerous gases, convert them to a poison, and then leak the substance through their cell walls. The toxins vary constantly.
60. Standard mushrooms that grow in muscles induce the following: twitching, loss of balance, ataxia, seizures, a coma-like appearance.
61. Some potent mushrooms that grow in muscles inhibit their ability to contract. If the fungi find their way to the heart it means at some point it will stop beating.
62. Some spores that lodge and grow around the eyes affect the ability to use handheld weapons effectively as they induce either macropsia (targets appear larger than they are) or micropsia (targets appear smaller).
63. Some spores that lodge and grow around the eyes affect the ability to use ranged weapons effectively as they induce either teleopsia (targets appear further away than they are) or pelopsia (targets appear closer).
64. Some spores that grow around organs act as a break on physical development. They have the potential to double the life span of a creature but its development rate is halved. This slows class development rates if the GM choses.
65. Some fungi can grow periodically at the same rate as a plant growth Their mycelia are swift enough to snare targets the same size category or smaller as the host fungi.
66. Some fungi plug into the root tissue of specific trees or plantae and link them together. This is known to affect even treants and shambling mounds, holding them in place.
67. It is believed that several species of aggressive, sentient fungi can use tree stride as a natural ability so long as their mycelia are connected to tree roots.
68. Given enough time, mushrooms turn the most barren-seeming caves into places where plants and creatures can survive, so long as air currents move through them.
69. Intelligent creatures that live in the deepest areas of the Underworld, where the flow of fresh oxygen is often problematic, use mushrooms to trap carbon dioxide from the air.
70. Many experienced miners use specific species of fungi to remove toxic gases from the air. Some of these mushrooms prove to be unique to the mine, but are transplantable.
71. Some fungi that absorb toxic gases store them rather than use them to grow. Drow and others use these mushrooms to release the gas elsewhere, as per a cloudkill
72. It is believed that some species of calculating, sentient fungi can animate plants, as if they can animate objects, so long as their mycelia are connected to the roots.
73. It is believed that a few species of learned, sentient fungi can conjure shambling mounds, as if they can raise dead, from the rotting detritus around them.
74. Many species of fungi provide nutrients, even healing, to the plants and trees that are linked to their mycelia. This transfer is swift enough to heal something being attacked.
75. Many creatures that experience being linked to fungi swiftly become reluctant to break the connection and leave the area controlled by the mushrooms, whatever its size.
76. Many fungi, once mycelia are linked to other creatures, pass information about events that affect other conjoined beings, teaching each member how to deal with them.
77. Some of the most robust species of fungi channel features from a conjoined growth to anything attached to its mycelia, both to protect it and boost its attacks at times.
78. Some fungi with low intelligence use their mycelia “introduce” mis-matched plants, letting the mushroom act as a “go between” across species that usually compete.
79. Some fungi with better-than-low intelligence use their mycelia to “introduce” mis-matched creatures as they sleep, letting a mushroom act as a “go between” across species that are usually aggressive or combative towards each other.
80. Mobile fungi of average intelligence grow to whatever size is best suited to their environment, from tiny to gargantuan and all sizes between.
81. When a creature walks in a fungi forest, they regularly and frequently enter the space taken up by a mushroom because they move through its spore clouds.
82. When a creature walks in a fungi forest, they regularly and frequently enter the space taken up by a mushroom when they tread on its mycelia, which may grapple them.
83. Intelligent but non-mobile fungi will use creatures with cutting mandibles, from ants to ankhegs and beyond, to gather food for them in return for pleasurable chemicals.
84. Wise fungi learn to give “just enough food just in time” to the creatures that work for them. If more is suddenly needed, the mushroom sprouts versions of itself that match the size of a meal for the creature, but only if the fungus values it.
85. Some intelligent fungi that conjoin with particularly valuable creatures will replicate natural diseases that slow the worker down if tries to leave, e.g., severe athlete’s foot or ringworm in a humanoid.
86. Evil fungi that enslave creatures infect them with histoplasmosis to stop them leaving. The chest inflammation is used to kill rebellious workers, who become food for all.
87. Some controlling fungi find ways to convince host humanoids to create hard-to-find “closed communities” in which outsiders are killed and turned into mulch.
88. Some controlling fungi gain cult status amongst host humanoids by granting members spell-like abilities such as darkvision or spider climb that help defend the faction.
89. Vast fungi patches enslave whole villages by infecting other food with spores that cause ergotism, the effects of which range from nausea, a constant burning sensation, muscle spasms, and gangrenous rot.
90. While most surface foods are hard to find in the Underworld, fungi supply yeast and cereal-like material for a never-ending range of breads, cheeses, beers, and wines.
91. While dried mushroom stalks and planks are excellent building materials, some species of fungi produce itaconic acid that is used to make a plastic-like material (the same as Lego), so that brick-built structures are found deep in the Underworld.
92. Virtually all species of fungi produce chitin within their cell structure, but some have taken this to an extreme and grow patches that cover them like arthropod-style armor.
93. Some species of fungi, such as the Ganodermas, are eaten by humanoids that want some light as they travel the Underworld as they cause the skin to glow.
94. While species of fungi frequently compete aggressively for space and resources most combine abilities and features to drive off unwelcome “incomers” of any type.
95. Unintelligent carnivorous or predaceous fungi species gain much of their food from trapping and eating creatures appropriate for their size. Prey is usually three categories smaller than the fungi, e.g., “tiny” fungi eat microscopic prey, while “huge” eat “small.”
96. Semi-intelligent non-carnivorous or non-predatory fungi species often gain additional food by allowing carnivorous plants like bladder and pitfall or flypaper and snapper trappers to take root on them. The host fungus controls these plants, even as weapons.
97. Fungants – the fungi version of treants – pick up the scent of mushrooms being cooked from as far as five miles away. They take appropriate action when they find the cook.
98. Fungiants – the fungi version of giants – feel the tremors of mushrooms being cut down as far as one mile away per size category from medium and above, taking appropriate action when they find the logger.
99. Many intelligent creatures that developed from fungi species that thrive deep in the Underworld can take root in the general mycelia if they remain motionless for five rounds. This grants them blindsight of one mile per prime ability point while immobile.
100. It is difficult to eradicate virtually all species of Underworld fungi because they use two, three or even more methods of reproduction, some of which are activated only when certain detrimental conditions occur, such as taking a particular type of damage.

We would love to hear how you are using them in your games, especially if your players have come up with inventive solutions or you have adapted them for specific environments. And if you would like any puzzles or riddles on a topic or subject that is coming up in your adventure and would like us to help, do please let us know!