Plane of Dreams, Oneirion, The Veiled Dominion

Oneirion is the plane where sleep becomes country, memory becomes road, and every nightmare knows the name of the dreamer.

Formerly called the Twilight Expanse

• Plane Type: Transitive Plane
• Moral Gravity: True Neutral
• Common Names: Oneirion, the Plane of Dreams, the Veiled Dominion, the Dreaming Sea, the Nightward Mirror
• Older Name: The Twilight Expanse
• Primary Function: Passage-realm of sleeping minds, divine dreams, nightmares, memory-echoes, prophecy, dream-magic, and subconscious revelation
• Usual Arrival Point: Unreliable; travellers usually arrive inside a dream, beside a silver road, before a gate of horn or ivory, in a memory-landscape, or at the edge of another sleeper’s nightmare

The Plane of Dreams is the hidden sea behind sleep: a transitive realm of visions, memory, prophecy, nightmare, desire, and half-formed truth.

Oneirion is not a normal country, not a heaven, not a hell, and not the Feywild. It is the realm through which dreams move before they become memory, omen, madness, inspiration, prophecy, or waking action.

A traveller walking through Oneirion may cross a childhood bedroom that opens into a battlefield, a moonlit orchard where every fruit contains a forgotten name, a courtroom where the judge is the traveller’s own guilt, or a city built from impossible stairways and half-remembered doors. The plane changes constantly, but it is not random. It answers sleeping minds, divine attention, buried fear, unresolved desire, unfinished grief, and stories trying to become true.

The Plane of Dreams is beautiful, dangerous, and intimate. It does not merely show what a traveller wants. It shows what a traveller is still carrying.

Quick Rules Reference

• Oneirion is a True Neutral Transitive Plane.
• The plane reflects dream, memory, fear, desire, prophecy, and symbolic truth.
• It is not the Feywild, though the Feywild and dream-magic often touch it.
• Illusion, divination, enchantment, sleep, dream, memory, and prophecy magic are unusually strong.
• Fire, death, force, and physical distance may work symbolically rather than normally.
• Travellers need waking anchors: names, vows, scars, holy symbols, songs, pain, or tokens from home.
• Dream death is not always bodily death, but it can trap, wound, rewrite, or sever the soul.
• The Nightward is the nightmare-depth of the plane, not the whole plane.

Cosmological Role

Oneirion is the dream-depth of the multiverse. It lies close to the Astral Sea, brushes the Ethereal Plane, casts long reflections into the Shadow Plane, and sends dream-substance toward the Feywild and the mortal imagination.

The Astral Sea carries thought, soul, symbol, and divine distance. The Ethereal Plane carries ghostly nearness, hidden passage, and border-presence. The Shadow Plane carries loss, fear, reflection, and absence. Oneirion carries sleeping perception, subconscious truth, symbolic consequence, and unstable possibility.

The Feywild is a separate Other World of heightened nature, living glamour, fey courts, and primal excess. Oneirion is deeper and less bodily. It is the dream-current beneath image, story, prophecy, nightmare, and inspiration.

A wizard may use the Astral Sea to seek a god’s domain. A ghost may drift through the Ethereal Plane. A shadow-worker may cross the dark reflection. But a poet, child, cursed king, dying soldier, sleeping saint, or plague-haunted village may touch Oneirion without ever leaving bed.

Timeline Placement

Oneirion begins as pressure before it becomes place.

Its first roots belong to the weaving of thought, dream, memory, longing, and unrealised intent into magic. At first there is no stable dream-plane. There are only currents: silver thought, violet dream, golden memory, fear, hope, desire, and meaning moving through the early multiverse.

As mortal minds multiply, the currents thicken. Dreams begin to repeat. Repeated dreams become paths. Shared fears become hunting grounds. Sacred dreams become temples. Prophecies learn to wear symbolic bodies. Nightmares gather in the dark below sleep.

By the time gods of sleep and dream become known by name, Oneirion is already ancient. Hypnos, Morpheus, the Oneiroi, and other dream-powers do not create the plane from nothing. They claim offices, thresholds, courts, masks, gates, and laws inside a realm that has been growing wherever minds sleep and imagine.

Divine Powers and Dream Sovereigns

Hypnos, Somnus, God of Sleep

Hypnos is the divine sovereign of sleep, rest, mercy, drowsiness, and the closed threshold between waking life and dream. His primary divine seat remains with the Hellenic powers, but his authority enters Oneirion wherever sleep becomes sacred, healing, prophetic, or absolute.

He is not merely a god who lives in the Plane of Dreams. He is one of the powers that makes sleep survivable.

His signs include poppies, soft ash, silver eyelids, slow bells, feathered shadows, and the impossible silence that falls just before sleep takes hold.

Morpheus, Shaper of Dream Form

Morpheus gives dreams faces, rooms, voices, bodies, masks, and narrative shape. Where Hypnos governs the descent into sleep, Morpheus governs what the sleeping mind can meet once it has crossed the threshold.

Morpheus is especially important to artists, poets, seers, actors, diviners, insomniacs, and those who must confront a truth they cannot bear while awake.

His signs include masks, folded wings, unfinished statues, moonlit doorways, theatrical curtains, and figures who look exactly like someone the dreamer cannot forget.

The Oneiroi

The Oneiroi are dream-messengers, mask-bearers, nightmare-riders, and emissaries of symbolic truth. Some bring warnings. Some bring healing sleep. Some bear divine messages. Others lie, possess, devour, or twist dreams toward fear and ruin.

Use two broad currents.

The Horn Gate Oneiroi bring true dreams, warnings, divine messages, healing visions, and symbolic revelations.

The Ivory Gate Oneiroi bring false dreams, seductive lies, nightmare traps, corrupted prophecies, and dream-possession.

This keeps Oneirion neutral while allowing darker Oneiroi to exist as real threats.

The Laws of Oneirion

Dream-Reality

Objects in Oneirion are real while the dream sustains them. A sword of moonlight may wound. A remembered door may open into a dead city. A lie believed strongly enough may become architecture.

Dream-reality is not the same as illusion. The plane does not simply trick the eye. It gives temporary substance to symbol, memory, fear, and desire.

Identity Pressure

Travellers are not judged only by what they say they are. The plane also responds to guilt, longing, shame, oaths, memories, fears, names, titles, and denied truths.

A knight who claims to fear nothing may find himself armourless before a dragon made of witnesses. A murderer who calls himself innocent may be followed by a child with no face. A grieving mother may find a cottage where the dead still sing.

Symbolic Distance

Distance follows meaning before measurement. A traveller may reach a lost mother by following lullabies, a murdered king by descending a staircase of bloodied crowns, or a stolen name by walking through every door marked with the wrong one.

Maps help only when the map understands the dream.

Mutable Time

Time in Oneirion is unstable. A single night of sleep may contain a year of wandering. A week spent in the plane may leave only a few hours missing in the waking world. Deep dream-regions, divine dreams, and nightmare prisons are especially unreliable.

Use time distortion sparingly at the table. It is strongest when it creates consequence: missed dawn, changed memory, aged grief, prophetic warning, or a rescue that must finish before the sleeper dies.

Waking Anchors

Names, true memories, companions, oaths, pain, scars, holy symbols, and tokens from the waking world help travellers remember what is real.

A traveller with no anchor becomes easier for Oneirion to rewrite. Those who lose every anchor risk becoming sleepwalkers, dream-petitioners, masks, or hollow figures wandering through someone else’s nightmare.

Nightmare Gravity

Fear sinks.

The lower and darker parts of Oneirion draw terror, guilt, predatory dreams, broken prophecies, and unprocessed grief. These depths are not evil in the way the Lower Planes are evil, but they are dangerous. They do not punish sin. They feed on what the mind cannot master.

Regions and Dreamlands

The Veil of Sleep

The Veil of Sleep is the soft border by which most mortals touch Oneirion. It is seen as falling snow, closing curtains, drifting ash, a dark sea, a field of poppies, a silver mist, or an endless hallway lit by lamps that are almost out.

Most dreamers never pass beyond the Veil. They see only their own dream-shapes and wake before the deeper plane notices them.

The Silver Roads

The Silver Roads appear beneath travellers who know they are dreaming. They run between stable dreamlands, divine visions, prophetic courts, and safer thresholds.

The roads are more reliable than wandering the mist, but they are not tame. A Silver Road may bend toward the truth a traveller most needs, not the destination the traveller asked for.

The Gates of Horn and Ivory

The Gate of Horn opens toward true dreams: warnings, revelations, healing visions, divine messages, and symbolic truths.

The Gate of Ivory opens toward false dreams: lies, temptations, evasions, fear-masks, and pleasing illusions.

Both gates may appear as literal doors, animal horns, white towers, archways in the sky, carved masks, or two roads parting beneath a moon. A wise traveller does not assume the beautiful gate is the true one.

The Dreamwell

The Dreamwell is a deep black-silver pool where forgotten dreams fall.

Diviners seek it for lost prophecies, stolen memories, erased names, and visions deliberately buried by gods, archmages, guilty monarchs, or dying saints. The Dreamwell never gives an answer without taking something into itself.

The Whispering Orchard

The Whispering Orchard is a moonlit grove where fruits contain memories.

Some fruits restore what was lost. Some reveal memories that never belonged to the eater. Some contain the last dream of the dead. Some taste sweet because they are lies the dreamer still wants to believe.

The Glass Reversal

The Glass Reversal is a mirror-land of polished floors, hanging panes, reversed rooms, and speaking reflections. Travellers here meet the selves they deny: coward, tyrant, saint, child, beast, traitor, lover, corpse.

The Glass Reversal does not exist to shame travellers. It exists to remove disguise.

The Court of Sleepwalkers

The Court of Sleepwalkers is a drifting city of those who entered Oneirion too often and forgot the way back.

Some sleepwalkers are harmless. Some are prophets. Some are puppets for things that learned to wear their dreams. Some still have living bodies in the waking world, standing beside windows, walking across roofs, or lying unwakeable in guarded beds.

The Nightward

The Nightward is the dark pressure beneath dream.

Nightmares gather here. Predatory Oneiroi, sandmen, thought-eaters, living fears, guilt-wraiths, and id-manifestations hunt among ruined bedrooms, endless corridors, burning stables, drowned churches, childhood cellars, and battlefields that repeat until someone breaks the pattern.

The Nightward is not the whole Plane of Dreams. It is the place travellers reach when the dream stops warning them and starts hunting.

The Palace of Night

Some scholars place the darkest Oneiroi near the Palace of Night, a black fastness where dream, death, shadow, and punishment overlap. It is not the safe capital of Oneirion. It is a border-horror: a place where false dreams, nightmare possession, and nightward messengers become organised.

Use it when the campaign needs the Oneiroi as villains, not as the default centre of the plane.

Inhabitants

Oneirion’s inhabitants are not all native in the same sense. Some are dream-born. Some are divine servants. Some are predators from adjacent planes. Some are pieces of mortal minds that became independent. Some are visitors who forgot how to wake.

Oneiroi

The Oneiroi are dream-messengers and nightmare-bearers. They may appear as winged figures, masked youths, beautiful strangers, black-feathered heralds, animals speaking with human voices, or familiar faces whose eyes belong to something else.

Horn Gate Oneiroi bring warning and revelation.

Ivory Gate Oneiroi bring false prophecy, possession, and dream-harm.

Sandmen

Sandmen are sleep-haunting predators, dreamdust spirits, and thieves of sight, rest, and memory. Some are corrupted stewards of sleep. Others are old dream-parasites wearing a comforting nursery shape.

They are drawn to children, insomniacs, guilt-ridden adults, and households where no one has slept well for many nights.

Nightmares

Nightmares are fire-and-shadow steeds that cross dream, evil planes, and border-realms. In Oneirion they are often mounts, omens, or hunters rather than ordinary animals.

A nightmare’s hoofbeats may mean pursuit, punishment, war, false prophecy, or a rider from the Nightward.

Thought Eaters

Thought eaters are psychic predators that feed on thoughts and memories. They are not dream-spirits in the pure sense, but Oneirion attracts them wherever exposed minds, sleeping bodies, and memory-rich dreamlands make feeding easy.

A thought eater infestation can leave a village rested but empty, with people unable to remember names, roads, children, oaths, or sins.

Id Manifestations

An id manifestation is a primal subconscious urge given shape. It may be hunger, lust, rage, fear, envy, grief, shame, or survival instinct made monstrous.

Such beings are not moral teachers. They are the unreasoning force beneath the dreamer’s civilised self.

Alps

Alps are nightmare demons that press upon sleepers, steal breath, sour rest, and turn ordinary dreams into suffocating terror. They are not true citizens of Oneirion. They enter through the Nightward, haunted bedrooms, cursed sleep, witchcraft, and fear-heavy dreamlands, feeding where the boundary between body and dream is weakest.

Sleepwalkers

Sleepwalkers are travellers, victims, mystics, children, soldiers, prophets, or spellcasters who lost the path back to waking life.

Some still have bodies. Some no longer do. Some are only the part of a person that stayed behind.

Dream-Petitioners

A dream-petitioner is usually not a normal soul awaiting judgement. More often it is a fragment, dream-echo, unfinished desire, stolen memory, death-vision, or last dream that could not pass cleanly into afterlife, judgement, reincarnation, or oblivion.

Some know they are dead. Others repeat the same dream forever.

Personhood and Law

Not every dream-shape is a person.

A single fear, false image, symbolic animal, or temporary dream-body may be only part of the dream. Destroying it may change the dream without killing anyone.

A stable, self-aware dream-being with memory, will, name, continuity, and the ability to bargain should be treated as a person unless the campaign establishes otherwise. Killing such a being may have moral, divine, or political consequence.

A sleeping mortal’s dream-form is not always the mortal’s soul. Wounding it may cause fear, exhaustion, memory loss, madness, or spiritual harm, but it does not automatically kill the waking body unless the dream-form is bound to a true soul-anchor.

Travel and Arrival

Most travellers reach Oneirion through sleep, dream magic, divine summons, cursed mirrors, haunted beds, prophetic illness, fey thresholds, shadowed ruins, drugged rites, sacred poppies, or failed astral travel.

Physical arrival is possible but dangerous. A waking body inside Oneirion is heavy with contradiction. The plane may try to translate the body into symbol: armour becomes guilt, wounds become words, blood becomes ink, and maps become childhood drawings.

Good waking anchors include:

• a true name;
• a companion’s hand;
• a holy symbol;
• a remembered song;
• a written oath;
• a scar;
• a token from home;
• pain that proves the body still exists.

Leaving Oneirion

Leaving Oneirion usually requires one of the following:

• waking the sleeping body;
• finding a Silver Road back to the Veil of Sleep;
• speaking a true name at a threshold;
• passing through the Gate of Horn with a true dream completed;
• rejecting a false dream at the Gate of Ivory;
• fulfilling the symbolic demand of a nightmare;
• being called back by an ally in the waking world;
• divine intervention from a power of sleep, dream, dawn, death, healing, or prophecy.

The plane rarely prevents departure out of malice. It prevents departure when the dream is unfinished, when the traveller has lost identity, or when something else has learned to hold the dream shut.

Magic in Oneirion

Illusion, divination, enchantment, dream, memory, sleep, prophecy, and mind-affecting magic are unusually strong in Oneirion.

Evocation and necromancy are unstable unless shaped through dream-symbol, fear, memory, or divine authority. Fire may burn as shame. Lightning may strike only liars. A corpse may speak only in lullabies. A sword may do nothing until the wielder remembers who gave it to them.

Conjuration works, but summoned creatures often arrive altered by the dream’s meaning. A wolf summoned by a guilty hunter may appear wounded. A celestial called by a faithless priest may arrive faceless. A fiend called inside a nightmare may already know the dreamer’s name.

Planar Effects

Dream Logic

Cause and effect remain present, but they bend around symbol, fear, desire, and memory. A locked door may open to a confession rather than a key. A monster may be defeated by naming it correctly. A battlefield may end when the dreamer refuses to keep playing the defeated role.

False Awakening

Oneirion often pretends to release travellers. A character may wake in their own bed, only to notice the windows look onto the wrong city, an old wound has moved, or a dead friend is making breakfast.

False awakenings are common near Ivory Gate dreamlands and in the Nightward.

Memory Drift

The longer travellers remain, the more their memories become available to the plane. This does not mean every secret is exposed at once. Instead, memories become props, doors, weather, witnesses, roads, enemies, or food.

Nightmare Pressure

In the Nightward, failed resolve, repeated panic, broken anchors, and unresolved guilt attract predators. The longer travellers remain, the more the plane learns what will hurt them.

Mechanics Tabs

The rules below are mechanics compatible for different game editions.

Running the Plane

Use Oneirion when the campaign needs revelation, rescue, temptation, prophecy, memory, curse-breaking, or psychological pressure.

Do not make every dream obscure. Give players clear images, repeated motifs, visible consequences, and practical choices. A dream should feel strange, but the table still needs decisions it can understand.

Good Oneirion scenes include:

• entering a king’s dream to find the name of his murderer;
• rescuing a child from a sandman before the body dies of dreamless sleep;
• crossing the Glass Reversal to recover a memory stolen by a thought eater;
• bargaining with Morpheus for the true form of a prophecy;
• hunting an Ivory Gate Oneiros spreading false visions before a war;
• waking an army from a shared nightmare before dawn;
• finding which dream belongs to the dead and which belongs to the living;
• carrying a true dream through the Gate of Horn before the Gate of Ivory replaces it.

Oneirion works best when the players can change outcomes by interpreting symbols, protecting anchors, naming fears, rescuing trapped dreamers, confronting false comforts, and refusing the roles nightmares assign them.

Best Three Adventure Hooks

The King Who Dreams of Treason

A sleeping king names a different traitor every night, and each named noble dies before dawn.

The dreams are not simple prophecy. Someone has placed an Ivory Gate Oneiros inside the royal sleep, turning fear into political murder. The party must enter the king’s dream, identify the false gate, and learn who benefits from making the crown afraid of everyone.

The Child Without Dreams

A child blessed by Hypnos no longer dreams. Every night, more colour drains from the household, then from the street, then from the city quarter.

A sandman has stolen the child’s dream-anchor and hidden it in the Nightward. The child cannot wake fully, cannot sleep truly, and has become a doorway through which dreamlessness is spreading.

The Mirror That Remembers Better

A mirror in a noble house reflects crimes before they happen.

The Glass Reversal is leaking into the waking world, and the reflections are not predicting the future. They are choosing it. The party must enter the mirror-dream, confront the denied selves of the household, and decide whether the mirror is an oracle, a curse, or a hungry judge.

Treasure and Rewards

Oneirion rarely gives ordinary treasure unless travellers brought physical bodies into the plane or seized objects from a stable dreamland.

Better rewards include:

• a true dream that reveals a hidden threat;
• a restored memory;
• a name removed from a nightmare’s power;
• a prophecy corrected at the Gate of Horn;
• a false prophecy exposed at the Gate of Ivory;
• a sleeping victim restored;
• a dream-key that opens one symbolic lock;
• a poppy-blessed charm against magical sleep;
• a mirror-shard that reveals false awakenings;
• a memory-fruit from the Whispering Orchard;
• Morpheus’ favour for artists, diviners, or dream-walkers;
• Hypnos’ mercy for the exhausted, cursed, dying, or sleepless.

Historic and Mythic Context

The Plane of Dreams draws on ancient Mediterranean, medieval, and folkloric traditions in which sleep is not merely rest, but a threshold between mortal life, divine message, omen, death, healing, and deception.

In Greek myth, Hypnos is the personification and god of sleep, closely associated with night, death, dreams, and the soft power that overcomes gods and mortals alike. His presence in the campaign makes sleep a sacred border rather than a simple condition.

The Oneiroi are dream-spirits or dream-messengers, traditionally associated with the gates of horn and ivory: true dreams passing through one gate, false dreams through the other. This distinction is useful at the table because it lets dreams matter without making every vision reliable.

Morpheus is treated here as the divine shaper of dream-form: the power that gives dreams faces, bodies, rooms, voices, and masks. This allows him to serve as patron of artists, prophets, actors, and dream-walkers without making him the sole creator of the Plane of Dreams.

Ovid’s account of Morpheus and the dream sent to Alcyone, preserved in the Metamorphoses, is especially useful for campaign play: dreams can comfort, deceive, warn, impersonate the dead, or reveal a truth too terrible to deliver by waking speech.

For the campaign, Oneirion is not simply a Greek realm. The Hellenic material gives names and offices to powers of sleep and dream, but the plane itself is older and wider than any single pantheon. Every culture that dreams touches it in its own language.