Realm of Mists & Mirrors

On Reddit recently, user wittmitin described a plane of existence:

It is the realm of the Shapeshifters and is made of an ever-shifting forest of mist and reflection. It is very easy to get lost inside.

And requested details which would make the place an interesting experience.

This seemed like a fun opportunity to brainstorm, and below is what I came up with.

So, elements in play in this realm: Fog, Mirrors, shapeshifters.

Navigating

Assuming this is a hex crawl, just progressing toward your destination is more difficult because of the tricky nature of the place. Each time you make two checks to navigate, though these are different depending on the local environment:

• Mist - In areas of excessive fog, each hex moved requires a Survival check and a Perception check to not get confused by the poor visual region.

• Mirrors - In areas where there is no fog, each hex moved requires a Survival check and a Insight check. Because of the ever shifting nature of the place, the only way to tell for sure where you're going is by reading the demeanor of your reflections. When getting close to specific goals or obstacles, hints in the reflection's personalities will tell you if you are in danger or on the right track.

The outcome of these checks determines your progress:

• If you pass both, you move in the right direction.
• If you pass only one check you either stay in the same zone or go only slightly off track (a hex adjacent to the one you intended).
• If you fail both checks, you travel in a random direction.

The same character need not make both checks.

Creatures

The Double-Half Animals - These are deer, rabbits, and similar forest creatures which look normal at first, but on closer inspection their bodies are bisected by mirrors. These are really two half-animals which move together along the mirror surface in perfect sync.

If you attempt to hunt and kill the animal, you automatically make two attacks (e.g. with an arrow). If both succeed, then the two halves of the animal are struck at the same time. If only one attack succeeds, then half the animal dies (50% chance mirror half, 50% chance natural half). In this case, the still-living half continues to run on along the surface of the mirror and may escape. If the mirror version survives, then you can see the inside of its bones, spine, organs, guts, etc.

The meat is edible 50% of the time. The other 50% the chirality of the molecules that make up the animal half is reversed, and will make you violently ill. An Intelligence check related to Arcana, Alchemy, Poison proficiency can tell if it is edible.

The Mirror People - In all the reflective surfaces, there are images of your party. All distorted, although some only barely so. Touching a mirrored surface frees one of the mirror people. They are always silent, but may or may not be hostile. Some might want to return to the mirror surface, some might flee to live free in the wood, some might attempt to kill their double, some will try to return to the prime material plane and take over their double's life. Only Insight checks can reveal their attitude toward the party.

• Stat the characters as if they were created via a Simulacrum spell.

On (not so) Little Cat Feet - There is a giant cat made of fog which moves utterly silently and is nearly invisible as it inhabits the denser foggy areas. It prefers to toy with its prey before eating. It is not invulnerable though, and you may be able to fascinate it with typical cat things (e.g. will attack the end of a rope beign pulled around a corner).

• Use Owlbear stats, except treat if effected by the spells: Greater Invisibility in fog or Blur outside of fog.

Unformed Changelings - Sometimes, usually in the distance, you can see a pale, amorphous humanoid shape walking haltingly through the forest, seemingly in confusion.  These are Changelings, humanoid shapeshifters, who have never before taken form.  They lack personality or clear purpose, and will continue in this state until they encounter a humanoid creature.

It is unclear these Unformed come into being.  Some believe they condense out of the mists or emerge like virtual particles from their own reflection.

If the Changeling is seen but doesn't detect the PCs, then it continues on its way in the same manner.

If it sees the PCs at a distance, it will halt for a moment, then begin to slowly approach.  However, it can be easily eluded, and will forget the PCs after a round or two.

However, if it encounters player characters at closer than 10 yards:

• The Changeling will take on the shape of the most charismatic character within the vicinity.
• The Changeling will begin to form it's own personality.  This will likely be unique in many ways, but will always be of opposite alignment to the person whose shape it first copied.
• While it will lack the specialized skills and abilities of the person it first copied, it will pick up very general forms of knowledge the character possessed, such as language and how a typical person in their homeland lives.
• The Changeling is unlikely to immediately attack, but may flee or try to integrate itself into the party before slipping away at an opportune moment.

Within a week of taking their first form, the Changeling will gradually take on the qualities of either a standard Changeling or a Doppelgänger with its own thoughts and goals.

Terrain & Environment

10,000 Years Bad Luck - Anyone smashing a mirrored surface that is part of the forest on purpose will take disadvantage on all their attempts while in the forest. This ends when they leave the realm, but for the rest of their life, their reflection will always appear to be screaming in horror.

The Impenetrable Fog - In certain areas the mist will become so thick as to be literally impassible, it gradually gets thicker and more difficult to push through until one gets stuck, as if in a Web spell.

The Whispers - In any foggy area, on a failed perception check you might hear whispers. Roll 1d6:

1. Whispers are unintelligible.
2. Whispers spout useless snippets. Bits of shopping lists, random questions, greetings to people you don't know.
3. Whispers say something about you personally that only a close friend might know.
4. Whispers mention trivia about someone else, possibly an enemy. Maybe true or useful.
5. Whispers tell something untrue or misleading.
6. Whispers are taunting, terrifying or getting too personal. On a failed Wisdom Save (DC 15), take the Frightened condition and flee randomly. Save attempt each round to stop.

Smoke & Mirrors - In some areas with thicker fog, a combination of fog and reflections will cause parties to become separated from each other. Thinking they are traveling together still, while only reflections of their comrades are nearby. It becomes very difficult to meet up again.

The False Foods - The mirror flora do grow here, and some are edible (e.g. mushrooms, fruit, roots, nuts, etc.). But these become extremely difficult to identify, since they change shape to resemble other fruit. To successfully find such a plant, make a survival check as usual. But to identify if it is edible, you will need to succeed at either an Investigate, Alchemy, Arcana or Insight check. This allows you to spot flaws in its disguise and figure out if it is deadly or not. Even if you identify that it won't kill you, there can be beneficial side effects similar to various spells. Roll percentile dice:

% Roll	Similar Spell	Details
01-49	n/a	Regular plant of its kind.  Edible. One ration worth.
50-52	Alter Self	Alters you to look like another character of your choosing. You must lock eyes with the character to duplicate them. This effects lasts until you leave the plane. Outside the plane it lasts the usual duration for this spell.
53-55	Bestow Curse	Your skin and everything in your possession becomes reflective as if in a mirror. The first time someone hits you, the surface shatters, and the one who hit you is afflicted with a Bestow Curse spell.
56-58	Blur	Within the plane, lasts until your next long rest. Outside the plane, lasts the usual duration.
59-61	Color Spray	Your body turns momentarily transparent, and any light passing through it refracts to produce a color spray.
62-64	Dimension Door	Works between any mirrored surfaces within range.
65-67	Disguise Self	Alters you to look like another character of your choosing. You must lock eyes with the character to duplicate them. This effects lasts until you leave the plane. Outside the plane it lasts the usual duration for this spell.
68-70	Fog Cloud	The fog cloud is centered on you and follows you, you can see through it, but others can not. Your cloud allows you to pass through Impenetrable Fog.
71-73	Gaseous Form	On this plane works until your next long rest, but elsewhere works normally.
74-76	Goodberry	It is just a very nourishing plant.
77-79	Grease	Not actually grease, the surface you throw the fruit onto simply becomes mirror finished and slippery as ice.
80-82	Magic Jar	An image of the person of your choosing becomes trapped within the crystaline fruit. Otherwise the spell works normally. One use per fruit.
83-85	Major Image	Throwing the fruit down, it becomes the image of your choosing.
86-88	Mirage Arcana	Works normally.
89-91	Mirror Image	Works normally.
92-94	Mislead	Works normally.
95-97	Prismatic Spray	Your body turns momentarily transparent, and any light passing through it refracts to produce a color spray.
98-00	Shatter	When struck like a bell and thrown, the fruit produces a destructive sound before it also shatters.