THE KNOWN PLANES OF EXISTENCE

There exist an infinite number of parallel universes and planes of existence in the fantastic "multiverse" of AD&D. 

All of these "worlds" co-exist, but how "real" each is depends entirely upon the development of each by the campaign referee. The chart and explanations which follow show only the various planes tied to that of normal existence. The parallel universes are not shown, and their existence might or might not be actual.

THE INNER PLANES (1-8)

1. The Prime Material Plane (or Physical Plane) houses the universe and all of its parallels. It is the plane of Terra, and your campaign, in all likelihood. The Prime Material is bounded or permeated by all of the Inner Planes and the Astral Plane. The Prime Material Plane is made up of the four elements plus positive and negative energy.

2. The Positive Material Plane is a place of energy and light, the place which is the source of much that is vital and active, the power supply for good. Any creature from the Prime Material that tried to enter the Positive Material Plane (e.g. from the Ethereal Plane) would probably be instantly consumed by the powerful energies there.

3. The Negative Material Plane is the place of anti-matter and negative force, the source of power for undead, the energy area from which evil grows. No one is certain what types of creature may exist on the Negative (or Positive) Material Plane. Any creature from the Prime Material Plane would probably be completely drained of all life and energy.

A. THE ELEMENTAL PLANES

The planes of Air, Earth, Fire and Water "surround" the Prime Material Plane. [The picture] shows one way of visualizing their relationship to each other and the other Inner Planes. The Elemental Planes are represented by the band that surrounds the Prime Material Plane(s). Don't be fooled by the apparent sizes of the planes represented. ... There are an infinite number of parallel Prime Material Planes, and each and every one of these are bounded by the Elemental Planes, so the Elemental Planes are themselves infinite, in effect. ... It is possible to actually physically move from one Elemental Plane to another by moving through the Para-Elemental Planes.

The Elemental Planes are the homes of many different kinds of elemental creatures, and some of them have the ability to travel to the Prime Material Plane. There is probably more traffic between the Prime Material and the Elemental planes than between any others. This is usually either direct travel (through gates or summoning) or by way of the Ethereal Plane. There are also nexial points in distant, out-of-the-way places on the Prime Material Plane that lead directly to the Elemental Planes. These nexial points would most likely be found in the deepest ocean (to the Plane of Water), high in the atmosphere (to the Plane of Air), far underground (to the Plane of Earth), or in an active volcano (to the Plane of Fire). Temporary nexial points may also be established occasionally, such as an opening to the Elemental Plane of Fire in the middle of a raging forest fire.

4. The Elemental Plane of Air.

5. The Elemental Plane of Fire.

6. The Elemental Plane of Earth.

7. The Elemental Plane of Water.

B. THE PARA-ELEMENTAL PLANES (not shown)

Where the Elemental Planes meet are the lesser Para-elemental Planes. These are:

— The Plane of Ice, where Air and Water meet.

— The Plane of Dust, at the conjunction of Air and Fire.

— The Plane of Heat, where Fire and Earth converge (lava).

— The Plane of Vapor, at the meeting of Earth and Water.

These planes are home to many para-elementals, and they can be reached in the same manners the Elemental Planes can be reached.

8. THE ETHEREAL PLANE

The Ethereal Plane is that which surrounds and touches all of the other Inner Planes, the endless parallel worlds of the universe, without being a part of any of them. The Ethereal Plane is basically insubstantial, and few "real" creatures actually live there (though there are rumors of floating islands of solid ether, populated by exiles, which drift about the Ethereal Plane). To creatures on the Ethereal Plane, objects on the Prime Material Plane (or any of the Inner Planes) appear as incorporeal phantoms. Ethereal creatures may pass through these phantoms with no difficulty, although a person being "passed through" might experience a chill down the spine. Ethereal beings or things are "real" to each other, however. Note that the Ethereal Plane does not extend to the Outer Planes, so it is not possible for creatures on those planes to "go ethereal". Ethereal travel and combat are explained later. Any creature able to become ethereal and then return to material form can use this plane to move from one to another of the Inner Planes; this is explained fully in the following paragraphs.

C. THE PLANE OF SHADOW (not shown)

The Plane of Shadow co-exists with the Prime Material Plane, and is a result of the interaction of that plane and the Positive and Negative Material Planes. The Negative plane provides the darkness, and the Positive plane the light; these meet at the Prime Material Plane, which casts the shadow. Thus the Plane of Shadow is a place of distorted and mutable shadow-creatures, of white, black and all shades of gray.

9. THE ASTRAL PLANE

The Astral Plane radiates from the Prime Material to a non-space where endless vortices spiral to the parallel Prime Material Planes and to the Outer Planes as well. Thus, this plane can be used to travel the universe(s) or to the Outer Planes which are the homes of powerful beings, the source of alignment (religious/philosophical/ethical ideals), and the deities. Note that the Astral Plane touches only the upper layers of the Outer Planes. Use of this plane is explained later.

THE OUTER PLANES (10-26)

These planes are the homes of the deities and the source of alignment (religious/philosophical/ethical ideals). There is an exact correspondence between alignment and the Outer Planes. [The Figures below] can be used to visualize this more clearly. Note that the alignment positions on the Character Alignment Graph match up exactly with the Outer Planes of identical alignment. There are nine basic alignments, and nine planes which correspond to those alignments. There are also eight other planes between the nine which represent "borderline" alignments.

As [the Figure] shows, alignment is a matter of degree rather than absolute definition. Thus, a Lawful Evil character who tended towards Neutral Evil would probably end up in Gehenna rather than Hades or the Nine Hells.

The seventeen Outer Planes are as follows:

10. The Seven Heavens of absolute Lawful Good.

11. The Twin Paradises of Neutral Good Lawfuls.

12. The planes of Elysium of Neutral Good.

13. The Happy Hunting Grounds of Neutral Good Chaotics.

14. The planes of Olympus of absolute Good Chaotics.

15. The planes of Gladsheim (Asgard, Valhalla, Vanaheim, etc.) of Chaotic Good Neutrals.

16. The planes of Limbo of Neutral (absolute) Chaos (entropy).

17. The Planes of Pandemonium of Chaotic Evil Neutrals.

18. The 666 layers of the Abyss of absolute Chaotic Evil.

19. The planes of Tarterus of Evil Chaotic Neutrals.

20. Hades' "Three Glooms" of absolute (Neutral) Evil.

21. The furnaces of Gehenna of Evil Lawful Neutrals.

22. The Nine Hells of absolute Lawful Evil.

23. The nether planes of Acheron of Lawful Evil Neutrals.

24. Nirvana of absolute (Neutral) Lawfuls.

25. The planes of Arcadia of Neutral Good Lawfuls.

26. The plane of Concordant Opposition of true Neutrals. [not shown, overlays in the center of the aligned planes.]

As can be seen [from the picture], the seventeen Outer Planes contact each other at their topmost layers. It is possible to move directly from the upper layer of one Outer Plane to an adjacent one (though it is not necessarily advisable or safe). Thus a being could go from the topmost layer of the Abyss to Pandemonium or Tarterus, and it is likewise possible to move from Hades to Tarterus, Gehenna, or the plane of Concordant Opposition.

TRAVEL IN THE KNOWN PLANES OF EXISTENCE

The Known Planes of Existence, offer nearly endless possibilities for AD&D play, although some of these new realms will no longer be fantasy as found in swords & sorcery or myth, but verge on that of science fiction, horror, or just about anything else desired. 

How so? The known planes are a part of the "multiverse". In the Prime Material Plane are countless suns, planets, galaxies, universes. So too there are endless parallel worlds. 

What then of the Outer Planes? Certainly, they can be differently populated if not substantially different in form.

Spells, magic devices, artifacts, and relics are known ways to travel to the planes. You can add machines or creatures which will also allow such travel. As far as the universe around your campaign world goes, who is to say that it is not possible to mount a roc and fly to the moon(s)? or perhaps to another planet? 

Again, are the stars actually suns at a distance? or are they the tiny lights of some vast dome? The hows and wherefores are yours to handle, but more important is what is on the other end of the route.

For those of you who haven't really thought about it, the so-called planes are your ticket to creativity, and I mean that with a capital "C"! Everything can be absolutely different, save for those common denominators necessary to the existence of the player characters coming to the plane. 

Movement and scale can be different; so can combat and morale. Creatures can have more or different attributes. As long as the player characters can somehow relate to it all, then it will work. This is not to say that you are expected to actually make each and every plane a totally new experience - an impossibly tall order. It does mean that you can put your imagination to work on devising a single extraordinary plane. 

For the rest, simply use AD&D with minor quirks, petty differences, and so forth. If your players wish to spend most of their time visiting other planes (and this could come to pass after a year or more of play) then you will be hard pressed unless you rely upon other game systems to fill the gaps. While as of this particular writing there are no commercially available "other planes" modules, I am certain that there will be soon - it is simply too big an opportunity to pass up, and the need is great.

Astral and ethereal travel are not difficult, as the systems for encounters and the chances for the hazards of the psychic wind and ether cyclone are but brief sections of ... Random Encounters, easily and quickly handled.

Other forms of travel, the risks and hazards thereof, you must handle as you see fit. For instance, suppose that you decide that there is a breathable atmosphere which extends from the earth to the moon, and that any winged steed capable of flying fast and far can carry its rider to that orb. Furthermore, once beyond the normal limits of earth's atmosphere, gravity and resistance are such that speed increases dramatically, and the whole journey will take but a few days. You must then decide what will be encountered during the course of the trip - perhaps a few new creatures in addition to the standard ones which you deem likely to be between earth and moon.

Then comes what conditions will be like upon Luna, and what will be found there, why, and so on. Perhaps here is where you place the gateways to yet other worlds. In short, you devise the whole schema just as you did the campaign, beginning from the dungeon and environs outward into the broad world - in this case the universe, and then the multiverse. 

You need do no more than your participants desire, however. If your players are quite satisfied with the normal campaign setting, with occasional side trips to the layers of the Abyss or whatever, then there is no need to do more than make sketchy plans for the eventuality that their interests will expand. In short, the planes are there to offer whatever is needed in the campaign. Use them as you will.

ETHEREAL TRAVEL

A character can achieve the ethereal state by various means which include magical ointment (oil of etherealness), magical items, magic spells and psionic discipline. It is possible to move to or about any plane which the Ethereal Plane permeates, and it is also possible to move from plane to plane ethereally.

To move on the Ethereal Plane, an entity has but to will movement for it to happen. If concentration upon movement lapses, progress immediately halts. Ethereal travel is tireless and rapid. Creatures in ethereal state need neither food, drink, rest nor sleep. 

Ethereal creatures may move from plane to plane by moving from the shadow of one plane to the shadow of another. This may be accomplished by concentrating upon moving to the desired destination. This gets easier with practice, as the being marks out a mental "trail" through the ether. 

The first time a journey between two points is made, the DM should check for encounters three times. On the second journey, he or she should check twice, and on all subsequent journeys between the two known points, only one check need be made. 

All movement and travel in the Ethereal Plane is subject to certain hazards. Some monsters are able to function partially in this plane, while some roam the plane freely. The worst hazard, however, is the Ether Cyclone.

The Ether Cyclone: The twisting vortex of the Ether Cyclone is caused by fluctuations of the Inner Planes, and as such, is only encountered on ethereal journeys between planes: There is a non-cumulative 5% chance per plane crossed that a party will encounter the Ether Cyclone.

[The] complete tables for encounters in the Ethereal Plane as well as for movement of the ether cyclone and its results [is found in Random Encounters].

ETHEREAL COMBAT

Though the Inner Planes are mere phantoms to creatures on the Ethereal Plane, such creatures will certainly be "real" to each other, and normal melee or spell casting is possible between ethereal beings. 

It is also possible to combat creatures who exist or function partially on the Ethereal Plane. Thus, those creatures whose attack forms extend to the ethereal can be attacked by ethereal creatures. It is only in these instances that spells can be cast from the Ethereal to the Prime Material Plane, and then they will only affect the creature with ethereal connections. Ethereal combat damage is actual damage.

ASTRAL TRAVEL

Astral travel is possible by various means including magic spells and psionic discipline. The Astral Plane touches only the endless Prime Material Planes and the 17 "first levels" of the Outer Planes. The Astral Plane does not touch any of the Inner Planes other than the Prime Material Plane. It is possible to move about, in, or to any of the Prime Material universes or to the first layers of the Outer Planes by means of astral travel (see the clerical astral spell for pertinent details).

As with ethereal travel, movement through the Astral Plane is speedy, and while there, the individual needs no food, drink, rest or even sleep. Beings in an astral state move from place to place simply by concentrating upon moving to the desired destination. As with ethereal travel, this gets easier with practice, as the astral traveler "learns the way". 

The DM should check for encounters three times on the first journey between two points, twice on the second journey, and only once on any subsequent journeys.

Travel on the Astral Plane can be dangerous due to the functioning or presence of monsters in or upon the plane. The Psychic Wind is the most dangerous, however, for it can either blow the traveler about so as to cause him or her to become lost (thus coming to some undesired world or plane or be out of touch for many days) or snap the silver cord (cf. astral spell) and kill the individual irrevocably. 

Along with ethereal encounter and travel tables, ... information pertaining to like activities on the Astral Plane [is found in Random Encounters].

Psychic Wind: Perhaps the most dangerous thing that can happen to an astral traveler is getting caught in the Psychic Wind. No one knows how or why the wind blows, but all fear its effects. The chance of a delayed or disrupted journey is a non-cumulative 5% per plane crossed (including alternate worlds of the Prime Material) or solar system traveled to (if journeying across the Prime Material). The effects of the psychic wind [are found in Random Encounters].

ETHEREAL & ASTRAL COMBAT

As on the Ethereal Plane, astral beings are "real" to each other, and can cast spells and melee normally. The major impediment to these activities is that astral travelers employing an astral spell or the psionic astral projection discipline do not carry their possessions with them into the Astral Plane (except for certain magic items that have a multi-planar existence, e.g. an amulet of the planes).

[Ed.: From Polyhedron #26, Dispel Confusion: Note also that the tuning forks employed in the cleric's plane shift spell bypass all such planography, allowing access directly to any plane. A gate spell bestows similar direct access.]

Beings traveling astrally by these modes will therefore have to rely on their natural weaponry or spells without material components in any astral melee. 

Most creatures can do no more than destroy the astral body, causing the silver cord to return to the material body and preventing further astral travel for a period of time.

Very powerful beings (gods, demigods, etc.) might be able to snap the silver cord, thus killing the astral and material bodies simultaneously.

PLANAR TRAVEL

The purpose of this section is to sum up all of the information that has been stated or implied about planar travel. 

First, travel among the Inner Planes: 

• This is usually done by means of the Ethereal Plane, as it permeates all of the Inner Planes. (It is not possible for creatures on the Outer Planes to "go ethereal".) 

• As with all planar travel, it is also possible to pass directly from one plane to another by means of "gates", thereby avoiding ethereal travel. A gate may be formed by a magic spell (such as a gate spell, or conjure elemental, which forms a direct opening between the planes) a magic item (e.g. an amulet of the planes, a well of many worlds, a cubic gate, or any of the various elemental-summoning devices), or divine intervention.

• There are also direct nexial points connecting the Prime Material and Elemental Planes.

Travel to and from the Outer Planes is usually by means of gates or via the Astral Plane. (Note that the Astral Plane can only be entered from the Prime Material Plane or one of the "first layers" of the 17 Outer Planes.) 

• If a being is gated to one of the Outer Planes, he comes complete with body and possessions, leaving no part of himself behind. 

• However, if a being astrally projects and travels the Astral Plane to one of the Outer Planes, he leaves his material body behind on the Prime Material Plane, connected to his essence by a silver cord. 

• If his material body is destroyed or the silver cord is snapped while he is in the Astral Plane, the being is permanently and irrevocably killed. 

• If he moves to one of the Outer Planes from the Astral Plane, a body forms around him, but it is devoid of possessions. Both bodies are now connected by the silver cord, and if either body is destroyed, the being will continue on in the remaining body (returning instantly to the Prime Material if the Outer Plane body is killed). 

• If the silver cord is snapped on the Astral Plane, the unoccupied body dies.

PLANAR EFFECTS ON MAGIC

[Ed.: Manual of the Planes p.7, 10: The myriad planes vary most dramatically from the Prime in their handling of magic and magical effects (spells available to magic-users, clerics, and their sub-classes). How a plane affects spells is handled by noting the plane's effects on spells of a certain type (the spell type is given in parentheses after the spell name in the Players Handbook...). ...On a particular plane, for example, abjuration spells may be severely limited, conjuration/summoning spells may have advantages, and divination spells may not function at all. Further, the physical limitations of a plane (such as the lack of gravity in the Astral, or the heat of the plane of elemental Fire) causes some spells to behave differently than in the Prime Material plane. ... In general, the ... rules [created by the DM that] govern [spells apply to] magical items [matching that category of spell type] on the known planes of existence.

Swords and miscellaneous weapons have their magical powers reduced the farther they are taken from their plane of origin. For each plane removed (full plane, not demi-plane or level of a larger plane), the sword or weapon loses one plus to hit and damage. A +2 sword from the Prime becomes a +1 sword in the Ethereal, and a nonmagical sword in an inner plane. Swords and weapons that become nonmagical in this fashion lose ALL their other abilities. Weapons enchanted for a specific purpose (such as the frostbrand, which is +3, +6 versus fire-dwelling creatures) lose one plus from both for each plane removed (+1, +4 when two planes removed, +0, +3 when three planes removed). These items retain their enchantment until they lose the pluses from both regular bonus and special enchantment. Those items that inflict physical damage (a maul of the titans) are affected as swords and miscellaneous weapons...

Armor and shields are also reduced in magical effect the farther they are taken from their plane of origin. These items' magical abilities are governed by the rules for the spells they duplicate. Again, the plane of origin for armor and shields is the plane where they are forged or discovered. Armor and shields that gain bonuses from quality workmanship or special nonmagical materials do not have those bonuses reduced.

Artifacts are unaffected by travel through the planes. If an artifact's power is used to create an impossible effect (such as summoning a nonnative god to the Ethereal plane), the artifact immediately plane shifts itself and its owner to the nearest planar location where it can use that effect.]

RANDOM DETERMINATION OF THE PLANES

If for some reason it becomes necessary to choose a plane of existence at random, the following tables may be used: