The planes of existence are different realities with interwoven connections. Except for rare linking points, each plane is effectively its own universe with its own natural laws. These include how gravity works (and modes of travel), how time passes (relative to other planes which can be very important to travelers), and prevailing energy effects. Other traits can exist given the infinite variations of reality and powers at work.
The Prime material planes are an infinite number of separate physical universes. The campaign world (planet) will normally exist in one of these universes. Because some items, spells, or abilities react differently the farther they are taken from the prime plane (if originating there), each plane is noted with the number of planes removed from the Prime plane (the “farther” away the more “planes removed”). For example, (1 plane) indicates a plane is one plane removed from the Prime. Some Prime planes have weaker connectivity to magic than others (magic either has a lesser effect, a chance of failure, or simply does not work possibly trapping those that cannot travel the planes using psionics).
These planes are typically used to journey to other planes or as a conduit to hop to a different area on the same plane. While the Ethereal Plane and Astral Plane can both be accessed from the Prime planes, the Inner Planes can only be accessed using the Ethereal and the Outer Planes can only be accessed using the Astral. In general, the Ethereal and Astral have no connectivity unless through a Prime plane.
(1 plane removed). (Time: Same as Prime) The ethereal plane lays like a gauze-like fabric connecting the prime planes with the Inner Planes. “Near” the prime material, physical objects appear duplicated in insubstantial form and creatures in the ethereal can “see” into the Prime material plane as if the objects, structures, or creatures are insubstantial ghostly duplicates. Creatures in the ethereal can move in their native mode in any direction (walking, swimming, climbing, flying, etc.) and there is no impedance given for gravity. Objects dropped in the Ethereal will “float” in place indefinitely. Most extra-dimensional spaces (bags of holding, portable holes, etc.) have their actual storage in the ethereal. These are seen as an inaccessible “bubble” (the contents indistinct/indeterminable) and the location (in the ethereal) is not related to the physical location of the magic item or extra-dimensional opening. Physical objects or terrain in the Prime block sight into the Prime but not ability to move (unless specially treated to hedge ethereal travel). Ethereal creatures are invisible to those on the Prime planes. Certain spells or abilities grant detection of ethereal beings from the prime.
In special areas, portals will be found leading to Inner Planes, particularly the Elemental Planes. These normally coincide with a landmark on a prime plane (e.g. a large volcano holding a portal to the Elemental Plane of Fire, etc.). Most, if not all portals from the Prime to an Elemental Plane (including transient “portals” such as conjuring spells) actually use the ethereal for transport. The Ethereal Plane can also be used for travel between Prime Planes. However, unless shown a path, there is an 80% chance of selecting the wrong plane (although this may not be obvious).
While the Ethereal is primarily a transitive plane, it does have a number of creatures that are common to its domain; Many incorporeal creatures exist (sometimes partially) in the Ethereal Plane (ex. ghosts). Creatures on the Ethereal Plane cannot affect creatures on another plane and creatures from other planes cannot affect those on the Ethereal Plane. Some special abilities will function as an exception to this rule.
One benefit of ethereal movement is that such movement causes no fatigue, thus all movement can be a maximum movement rate for as long as the creature can stay awake (sleep is still necessary but movement does not constitute physical activity).
An indistinct light suffuses the plane allowing normal sight out to 300 yards. If followed (and the traveler concentrates on it), the light source becomes brighter over time (2d6 days) eventually being blinding. This is the place where one can directly access the Positive Energy Plane.
Encounters. Moving in the ethereal will require the following number of encounter checks: Moving between 2 previously untraveled (in the ethereal) points = 3 checks (beginning, half-way, and end); If traveled once = 2 checks (beginning, end); If more than twice = 1 check (halfway). See Random Encounters.
(1 plane removed). (Time: Same as Prime) The plane of shadow is a little understood dark copy of the Ethereal Plane where the incorporeal structures of the Prime are themselves duplicated. Some say the plane exists as a demi-plane within the ethereal. Others insist it is a full plane in its own right, but a (slightly warped) shadow copy of the Prime, partially powered by the Negative Energy Plane. Surely, access to that energy plane can be found in the deep places of shadow. Those that support this theory point to the fact that the plane is only 1 plane removed from the Prime and the plane seems to be directly accessible through certain spells cast from the Prime (ex. illusionist “shadow” spells which operate at +10% effectiveness on that plane). In any case, the plane operates much as the Ethereal allowing creatures to exist partially in the prime and shadow at one time and if “near” the prime plane, structures tend to exist in the Shadow as they do in the Prime. Creatures on the Prime may be seen as indistinct shadows out of the corner of one's eye if one stops to really concentrate. The rule regarding ability to affect objects or creatures across planes holds as per the Ethereal Plane. Interestingly, some have reported that the Plane of Shadow hosts worlds duplicating those of the prime, but in many cases strangely warped. Creatures found in the Plane of Shadow are typically highly dangerous and hostile to Prime plane travelers. Spells with the light descriptor have a 20% chance of spell failure and operate at half-effectiveness. Light of any kind behaves strangely and will not reflect color on the plane.
(1 plane removed). (Time: subjective time is 1,000:1; see description) The Astral Plane is an infinite space filled with a diffuse glow and silvery haze. In some cases, matter has been trapped and floats, suspended in the nothingness.
Movement. Unless ambulating upon a piece of floating matter (some of which are very large), movement is akin to flying, although the method of propulsion is thought. Tactical movement rate is 30 feet per point of Intelligence per round. For every 10 lbs. of encumbrance weight carried, movement slows by 10 ft. per round. Intelligence will adjust capacity (use Encumbrance Adjustment table but use the creature’s Intelligence score to determine adjustment). It is important to note that, in the astral, magic items (with a permanent dweomer) have no encumbrance weight as it relates to movement. Other than willful thought-based movement, force used upon an object (or creature) will impart momentum based on mass and amount of force. Unless coming into contact with another force/object, momentum will continue indefinitely. Thus, creatures can move by pushing off of floating matter or even other creatures. A small object pushing off a very large one (a humanoid leaping off a floating island) will move 10 feet per round per point of Strength (indefinitely unless using will or another force to stop). Two creatures of similar size can push off of each other (or one against the other) and the creature’s Strength scores will be summed and halved to determine movement for both (or simply halved if one man-sized creature pushing against another man-sized creature or object). Large creatures pushing small ones or objects will move a maximum of 10 feet per round (assuming encumbrance is overcome). An example of this is a humanoid firing a bow. Each arrow fired will cause 10 feet of momentum added to existing speed. If at a stand still, encumbrance must be overcome before movement can begin. If attacking, range penalties apply and any missile use while moving incurs a -2 penalty to attack cumulative for each attack while moving until one round of mental movement is completed. If moving faster than mental movement allows, each round speed can be slowed by the amount of mental movement allowed. Otherwise, stopping, turning or changing direction is a minor action (movement). Unless acclimated to the environment (requiring months if not more time), any spell casting while moving will fail 20% of the time.
Time. While time passes at the same rate as the Prime plane, the effects of time happen at a 1,000 to 1 difference from Prime to Astral. This means that, while on the Astral, time feels as if it has slowed by a factor of 1,000. Examples include spell durations extend by a factor of 1,000, a creature will age 1 day out of 1,000, creatures do not need to rest but once every 1,000 days (indeed, they cannot—even to recover spells!). This effect is sure to have surprising consequences (poison does not affect a body, creatures do not become hungry, potions with onset times take a full day to begin working but then stay active for a week, etc.).
Getting There. The Astral Plane can be accessed by physically going there (ex. plane shift). However, most beings entering the astral do so by creating an astral "duplicate", called an Astral Clone, via a spell or ability. This duplicate is connected to the physical body (which enters a state of stasis) through an invisible, intangible silver cord (or life thread). This cord keeps the duplicate powered and brings the traveler’s psyche back to its body when the spell or ability is done. With exception of the life thread, an astral clone is a duplicate of the original creature including all carried possessions, magic or mundane. Items consumed or spells cast by the astral clone will actually be consumed. If a creature’s astral clone is “killed”, the silver cord will return to the physical body and the creature will go into a coma for 1d4+1 days. They must also make a reverse Constitution System Save or die (ie. a high Constitution score means almost certain death; those without a Con score will have a 5% of perishing). Items obtained while astral can be brought back if they can be carried. A silver cord cannot be affected except by special magic (if ever severed, the psyche and original body dies immediately).
Magic. Extradimensional magic will not work or be accessible while in the astral. Creatures cannot be summoned or conjured from any Inner or Prime plane (summoning creatures from Outer Planes works as do calling spells that call creatures native to the astral plane). [Teleport] effects always use the astral plane for transport. All magic that interacts with the Outer Planes uses the Astral Plane in some way ([summoning] spells, etc.).
Silver Mirrors. These are portals allowing access to the Outer Planes from the astral. Only the uppermost level of a plane can be accessed in this way. If one knows how, a silver mirror can be interacted with to scry a location (only) on the connected plane and then used as a portal to step through into that area. Treat this as per a crystal ball—firsthand knowledge means you've been there before and "familiar" means you spend more than a week in the location. Anything that will hedge scrying will also hedge this activity. An astral clone that enters an Outer Plane or Alternate Prime using this method will have a physical body created that allows basic survival on the plane (ability to breathe, environmental acclimation, etc.). These bodies will generally conform to the original creature and possess all carried items—although, depending on the nature of the plane, certain features will look or behave differently. Once through the mirror, the portal cannot be accessed again unless the creature can become astral again. An astral clone can always return to the originating body by using a complex activity (concentration).
Encounters. The GM will check for encounters three times on the first journey between two points (one new), twice on the second journey, and only once on any subsequent journeys (as the travelers learn more direct routes).
Astral Storms. These deadly occurances are rare but are known to blow travelers off course and have the ability to snap a silver cord. All who travel the plane are especially wary of these storms.
The Inner Planes are place of energy, in some cases, taking the form of the four elements: Air, Fire, Earth, and Water. Time. Time is subjective and, while time passes at the same rate as the Prime plane, the effects of time happen at a 2 to 1 difference from Inner Plane to Prime. This means time feels as if it runs at twice the speed. Thus, spell durations are cut in half and creatures must rest at twice the normal rate. Creatures native to the plane are generally immune to these effects.
(2 planes removed). (Time: subjective time is 1:2; see description above) This is a place of pure positive energy which acts as a power source for most life and magic. Being a place of pure energy, it is inhospitable to material creatures (which tend to explode upon entering the plane). Access to the plane is through the Ethereal, but the plane tends to engulf any venturing in the ether that come too near.
(2 planes removed). (Time: subjective time is 1:2; see description above) This is the opposite of the above Positive Energy Plane. It is a plane of pure negative energy and entropy. Undead and like creatures receive their power from this plane as does most “death” magic. Living creatures entering the plane are drained of all life and experience, becoming mindless undead until they are completely consumed. Direct access is usually through the Plane of Shadow and those that venture too near will be sucked in and consumed.
(2 planes removed). (Time: subjective time is 1:2; see description above) This plane is an infinite expanse filled with vari-colored skies and clouds. Chunks of matter float on clouds or suspended by winds or through some form of levitation. Most beings on the plane can fly. Non-mindless creatures that cannot fly will fall in a random direction, eventually hitting something. Mindless or inanimate objects will simply float in place unless propelled by some force. Air elementals rule the place along with the djinn and other native flying creatures. Light is provided by magical heatless “suns” scattered throughout the plane. While some light variation exists, most places in the plane are brightly lit. Winds, sometimes quite violent, are ever present, providing sustenance to the elementals. Gravity. Items will weigh less on this plane. Item encumbrance is half. Missile weapons can be used at twice normal ranges (if not rendered ineffective due to wind).
(2 planes removed). (Time: subjective time is 1:2; see description above) This plane is filled with volcanic worlds floating in a sky of pure flame. Temperature on average is 2,500°F. This means unprotected combustibles will immediately combust, stone turns to magma, and metals melt. Creatures not immune to fire take 10d10 fire damage per round. While somewhat cooler temperatures can be found on certain worlds (with solid ground/basalt, etc.), effects are still the same for creatures or items without protection. While there is plenty of air (with oxygen), many places are also filled with noxious gases making it impossible to breathe (it will take 1d10 rounds before a creature must begin holding its breath before suffocating). Movement is normal with creatures made of elemental fire able to traverse the places between worlds through a very rapid form of flight. Fire elementals rule here as do efreet and other fire-based creatures native to the plane. Gravity. This functions similarly to the Prime planes.
(2 planes removed). (Time: subjective time is 1:2; see description above) The plane of earth is filled, almost completely with soil, rock and stone. Chambers, rifts, and world-spanning caverns exist but these are known to collapse unless constantly maintained through strong magic. Earthquakes are frequent. Few areas are lit (by glowing stones). Earth magic is doubled here. Earth elementals and dao rule along with burrowing creatures native to the plane. Breathable air can be found, but is rare. Gravity. This is doubled here relative to most inhabited worlds on the Prime. Thus encumbrance weight is doubled and missile weapon range is halved. Non-native creatures will tire twice as fast as normal.
(2 planes removed). (Time: subjective time is 1:2; see description above) This plane is an endless expanse of liquid with floating structures and worlds floating within. Travel is by swimming, assisted by massive invisible currents allowing for rapid travel between areas. Creatures must breathe water to survive. Water elementals and marids rule here with a large number of native piscine and water breathing creatures. Gravity. This functions similarly to the Prime planes (centered around large masses). Buoyancy is a concern where there is a relative “up” (see Nautical Adventures above).
The Outer Planes house the infinite number of souls or spirits of those inhabiting the Prime planes. Deities (or “powers” or “gods”) reside here and, as such, each plane is strongly aligned. These planes are accessible from the Prime through the Astral plane (see above). Visitors from the Prime are viewed with suspicion as the beings on these planes typically have different goals and motivations than those from the material planes. Powerful creatures native to an Outer Plane that travel to the Prime and are destroyed there, will be rejuvenated on their plane of origin. When this happens they are generally restricted from returning to the plane where they were destroyed for a period of time.
Time. Time is the same here as the Prime, although most inhabitants are immortal.
Layers. Many of the Outer planes will have more than one “layer”. Each layer is treated as a full plane. Each Outer Plane with more than one layer will have a designated order to these layers with one “facing” the astral which becomes the entry point and then one must travel from there to access the next plane.
Magic. Because the Ethereal cannot be reached from the Outer Planes, magic (or creatures) that depend on this do not function (extradimensional spaces, etc.). As with the astral realm, summoning or conjuring creatures from the Inner Planes does not function. Once beyond the uppermost layer, magic requiring access to the Astral will not function. Thus, summoning or conjuring from other planes is not permitted. However, summoning a being native to the current Outer Plane will work assuming the summoning can access the being from another layer (summoning cannot summon creatures from the same layer unless the spell is a calling spell).
Upper Planes. These are the three planes of Good (11.-13.).
Oceanus. This river flows from its source in Elysium through the Upper Planes.
Lower Planes. These are the three planes of Evil (16.-18.). The River Styx. This river flows through and connects the Lower Planes.
Yggdrasil, the World Ash. This tree exists in the Upper Plains, the Astral, and, it’s “roots” are found Hades. Travel using the tree is typically not possible, although a sentience is said to allow some communication if not actual travel.
Vital Spark. Each being is set apart from inanimate matter by possession of a form of energy. This “life force” suffuses all living organisms. On top of this, sentient beings have an individual form of “consciousness” (sometimes referred to élan vital or anima). This comes in two forms: souls and spirits. It is thought that souls are immortal individual entities and spirits are transient with the ability to reform as new beings (having been reprocessed). Humans, half-elves and halflings along with dwarves and gnomes are considered to have souls. Because these souls are permanent beings, these creatures may be brought back from death through resurrection types of effects (even if their physical form was destroyed long ago). Other beings, especially those that are strongly aligned and/or worship higher powers (deities), have spirits. These creatures include elves, most humanoids (e.g. orcs, half-orcs, goblins, etc.), and other sentient beings. Wish-level magic can reform their spirit, but they cannot be raised/resurrected. When a creature dies, its soul or spirit travels to the appropriate Outer Plane based upon its alignment and/or power worshiped. Once there, a soul is there for eternity (in joy or torment). A spirit on the other hand makes the same journey upon death but, at some point, may be called back to the Prime to inhabit a new form, having been reprocessed and circumstances or decisions made will determine where the spirit goes when the new form dies (the cycle continues definitely). In the Outer Planes, the souls and spirits will be engaged in activities common on the plane or decreed by the local power (e.g. feasting and preparing for Ragnarök in Valhalla).
The seven layers of Heaven appear to ascend where each layer is accessed through travel up various massive mountains. Some layers have oceans and some are dominated by forests. Angels, devas, and titans rule here. Those spirits and souls strong in Law and Good reside here.
Elysium is an unbiased paradise existing between the two extremes of Valinar and Heaven. Its stunning mountains, rolling hills, and deep forests all match a visitor’s expectations of a pastoral paradise, but Elysium also contains mysteries that lead to enlightenment. Elysium is a sanctuary and a place of respite for all who seek redemption or illumination. Elysium‘s natives have willingly postponed their own transcendence to guard Elysium‘s enigmas, while celestial beings fight the forces of evil across the planes.
A vast land of untamed wilderness and wild passions, Valinar is the plane of benevolent chaos. Freedom and self-sufficiency abound here, personified in the natives of the plane. In Valinar, selfless cooperation and fierce competition clash with the violence of a raging thunderstorm, but such conflicts never overshadow the lofty concepts of bravery, creativity, and good unhindered by rules or laws.
Most visitors to this plane are drawn to this plane due to the eternal wars and battles that can be found here, and more importantly the valor and glory. Arriving on this plane a person must be ready to be challenged by any and everyone who might seek glory through combat, and while the towns and cities that exist across this plane can be a safe haven from the eternal warriors, the people are not always excepting of outsiders.
Nirvana is a bastion of order against the chaos of Limbo and the countless demonic hordes of the Abyss. A great city of eternal perfection, Nirvana‘s streets and buildings are paragons of architecture and aesthetics; everything is ordered and nothing happens by chance. While no one race rules Nirvana, Mechanoids make their homes here, forever striving to expand their perfect city.
Limbo is described as a place of pure chaos where everything is in constant motion and change, especially the landscape, which can shift unpredictably and randomly rolls over upon itself like liquid.
The nine layers of Hell form a structured labyrinth of calculated evil where torment goes hand in hand with purification. A plane of iron cities, burning wastelands, frozen glaciers, and endless volcanic peaks, Hell is divided into nine nesting layers, each under the malevolent rule of an archdevil. Torture, anguish, and agony are inevitable in Hell, but they are methodical, not spiteful or capricious, and serve a deliberate master plan under the watchful eyes of the disciplined ranks of Hells’ lesser devils.
The Gray Waste is despair, a plane of horrible greed that sucks the passion, identity, and will from those who enter it and gives nothing in return. There may be equal suffering on other planes, but other planes don’t rob those who suffer of their very essences while they find themselves being transformed into writhing worms or mournful shades.
There are no rules in the Abyss, nor laws, order, or hope. The Abyss is a perversion of freedom, a nightmare realm of unmitigated horror where desire and suffering are given demonic form, for the Abyss is the spawning ground of the innumerable races of demons, among the oldest beings in all the multiverse.
This catch-all category covers all extradimensional spaces that function like planes but have measurable size and limited access. Other kinds of planes are theoretically infinite in size, but a demiplane might be only a few hundred feet across.
Magic Items Granting Pluses. These include weapons, armor, shields, rings of protection, and cloaks of protection. For each plane removed from the Prime (assuming that is the native plane of the item), the item loses one "plus" to a minimum of "+0". An item that is +0 is considered mundane. The first layer of any Outer Plane is considered "2 planes removed" as the traveler must traverse the astral plane then enter the first layer of the Outer plane (no matter the type of travel used).
Items like weapons with more than one plus rating, for example, a "+1 reptile-bane sword (+4) that enters Avernus, the 1st layer of Hell (2 planes removed) will become a +0 reptile-bane sword (+2) which means the sword is only considered magical when used against reptiles. Certain items grant pluses in addition to other abilities (rod of smiting, staff of striking, staff of power, etc.) these pluses are unaffected by planar travel unless the items states "as a ring of protection" or "as a cloak of protection".
Other Magic Items. Extra-dimensional spaces cannot be accessed from the astral or any Outer plane. Otherwise, magic item functions are affected as per spells of like or similar effect.
Spells. Effects on spells (or spell-like abilities or innate abilities) tend to be from the particular "physics" of the individual plane or the alignment of the plane:
Travelers from the Prime planes are considered extra-planar creatures when in any Outer Plane and can be affected by native inhabitants as such (protection from evil/good effects, dismissal effects, dispel evil/good effects, holy/unholy word, etc.). If an effect sends an extra-planar creature to it's home plane, the traveler will be forced back to their home plane.
Spells requiring access to another plane won't function if there is no access to that plane. Examples include Ethereal access from Outer Planes (eg. rope trick), Astral access from Inner Planes (eg. teleport), or Shadow plane access from Outer Planes (eg. shadow monsters). [Conjure] spells do not function in the Astral or Outer Planes. [Summoning] spells do not function on any Inner plane. [Calling] spells will call strange types of creatures and depending on alignment of the caster versus the plane, these may well be hostile to the caster and uncontrollable.
Resurrect spells may cause a body to be contested by other spirits residing on the plane. A living body uninhabited by a creature's psyche (eg. magic jar) could be inhabited by a spirit.
Strongly aligned planes. Chaotic planes will impart strange appearances and will increase randomness where possible (polymorph effects can produce strange results, as could regeneration and reincarnation). Evil planes reduce the effectiveness of Good or holy spells (and vice versa). Detect evil/good on the corresponding aligned plane will not function (being washed out due to an overabundance of alignment sources).
Environmental effects may affect spells, for example a wall of ice cast in the Elemental Plane of Fire may quickly melt.
Priest Spells. Priests (clerics/druids), unless on the home plane of their deity, lose access to regain spells based on the number of planes removed from the Prime plane or the home plane of their deity. Note that lower level spells can fill higher level spell slots. Abilities granted, whether spell-like or innate, can be regained as normal (effects are treated as spells above).
One Plane Removed: All spells can be regained.
Two Planes Removed: Cannot regain 6th or higher level spells.
Three to Five Planes Removed: Cannot regain 4th or higher level spells.
Six or more Planes Removed: Cannot regain 3rd level or higher spells.
Abilities. Abilities are effected as per spells. Turn Undead and Command Undead will be empowered or weakened on Good and Evil planes (class level +/-1-4 depending on the plane).