The Inner Planes are the innermost planes of existence

Plane (Dungeons & Dragons)

The planes of the Dungeons & Dragons roleplaying game constitutes the multiverse in which the game takes place.In the earliest versions of Dungeons & Dragons, the concept of the Inner, Ethereal, Prime Material, Astral and Outer Planes was introduced; at the time there were only four Inner Planes...

 in the standard cosmology of the Dungeons & Dragons

Dungeons & Dragons

Dungeons & Dragons is a fantasy role-playing game originally designed by Gary Gygax and Dave Arneson, and first published in 1974 by Tactical Studies Rules, Inc. . The game has been published by Wizards of the Coast since 1997...

 role-playing game

Role-playing game

A role-playing game is a game in which players assume the roles of characters in a fictional setting. Players take responsibility for acting out these roles within a narrative, either through literal acting, or through a process of structured decision-making or character development...

. They are the building blocks of the multiverse

Parallel universe (fiction)

A parallel universe or alternative reality is a hypothetical self-contained separate reality coexisting with one's own. A specific group of parallel universes is called a "multiverse", although this term can also be used to describe the possible parallel universes that constitute reality...

, the elements

Chemical element

A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...

 and energies

Energy

In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...

 from which all of the material universe (the Prime Material Plane

Prime Material Plane

The Prime Material Plane is the central plane of existence in the Dungeons & Dragons role-playing game...

, or, in the 3rd Edition, simply Material Plane) is made.

The Inner Planes, the material building blocks of reality and the realms of energy and matter

Matter

Matter is a general term for the substance of which all physical objects consist. Typically, matter includes atoms and other particles which have mass. A common way of defining matter is as anything that has mass and occupies volume...

, stand in contrast to the intangible and esoteric Outer Planes, which include the realms of ideals

Ideal (ethics)

An ideal is a principle or value that one actively pursues as a goal. Ideals are particularly important in ethics, as the order in which one places them tends to determine the degree to which one reveals them as real and sincere. It is the application, in ethics, of a universal...

, philosophies

Philosophy

Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...

, and gods.

In the first edition there were initially four Inner Planes, consisting of the four classical element

Classical element

Many philosophies and worldviews have a set of classical elements believed to reflect the simplest essential parts and principles of which anything consists or upon which the constitution and fundamental powers of anything are based. Most frequently, classical elements refer to ancient beliefs...

s of fire, earth, air and water, as well as the energy planes of positive and negative material, and the ethereal plane.

In Advanced Dungeons & Dragons 2nd edition, the Inner Planes intersect each other to produce a number of other Planes. Probably the best analogy describing their relationship to each other is that of an octahedron

Octahedron

In geometry, an octahedron is a polyhedron with eight faces. A regular octahedron is a Platonic solid composed of eight equilateral triangles, four of which meet at each vertex....

: the northern pole is the Positive Energy Plane, the southern pole the Negative Energy Plane, and at the middle four points lie the Elemental Planes (based on the four classical element

Classical element

Many philosophies and worldviews have a set of classical elements believed to reflect the simplest essential parts and principles of which anything consists or upon which the constitution and fundamental powers of anything are based. Most frequently, classical elements refer to ancient beliefs...

s): Air opposite Earth, Fire opposite Water. They were an important part of the Planescape

Planescape

Planescape is a campaign setting for the Dungeons & Dragons fantasy role-playing game, originally designed by Zeb Cook. The Planescape setting was published in 1994...

 setting. Each edge is also either a para-elemental or quasi-elemental plane of its own.

Elemental Planes

The four Elemental Planes are the planes of Air, Fire, Water and Earth.

2nd edition also included the Para-Elemental and Quasi-Elemental Planes. The Para-Elemental Planes are produced where the Elemental Planes come into contact with each other: Smoke (Air and Fire), Ice (Air and Water), Ooze (Earth and Water), and Magma (Fire and Earth). The Quasi-Elemental Planes are produced where the Elemental Planes touch the Energy Planes: At the intersection of the Positive Energy Plane and the planes of Air, Earth, Fire, and Water are Lightning, Minerals, Radiance, and Steam respectively. Around the Negative Energy Planes are Vacuum, Dust, Ash, and Salt.

Note that none of the opposing planes touch one another, as they cancel each other out violently, particularly in the case of Positive and Negative Energy. Thus, Fire and Water do not touch, nor do Air and Earth. There is only one exception to this rule: the Prime Material Plane, which is composed equally of all 6 elements; Earth, Air, Fire, Water, Creation (Positive Energy), and Decay (Negative Energy).

Energy Planes

The Energy Planes are unique in that they are not composed of matter but rather a tangible form of creativeness or destructiveness. All life

Life

Life is a characteristic that distinguishes objects that have signaling and self-sustaining processes from those that do not, either because such functions have ceased , or else because they lack such functions and are classified as inanimate...

 (or unlife) depends on them. Despite this, energy elementals or other forms of native life are not common. The Xag-Ya (positive) and Xeg-Yi (negative) energon

Energon (Dungeons & Dragons)

In the Dungeons & Dragons fantasy setting, energons are enimatic, incorporeal outsiders found throughout the Inner Planes.-Publication history:...

s were the earliest such denizens to be introduced.

Negative Energy Plane

Also called the Negative Material Plane (in 1st Edition), this plane is the home of stagnation, entropy, and the undead

Undead (Dungeons & Dragons)

In the Dungeons & Dragons fantasy role-playing game, undead is a classification of monsters that can be encountered by player characters. Undead creatures are most often once-living creatures, which have been animated by spiritual or supernatural forces....

. Any unprotected living creature exposed to the Negative Energy plane has its life force rapidly drained and will die when they run out. Most Necromantic spells, including bolstering undead and "rebuke undead" abilities, draw on this plane and most undead creatures have an inherent connection to it.

Positive Energy Plane

Also called the Positive Material Plane (in 1st Edition), this is the plane of creation and energy, and is the total opposite of the Negative Energy plane. Despite the plane's life giving effects, living creatures entering the positive energy plane quickly become overloaded with life energy and may explode. Necromantic spells harming undead and "turn undead" abilities draw on this plane and most deathless creatures have an inherent connection to it.

Publishing history

In the original Monster Manual (1977) by Gary Gygax

Gary Gygax

Ernest Gary Gygax was an American writer and game designer best known for co-creating the pioneering role-playing game Dungeons & Dragons with Dave Arneson. Gygax is generally acknowledged as the father of role-playing games....

, the only elementals that appeared were those of fire, air, water, and earth. In the original Players Handbook (1978), no para- or quasielemental planes were mentioned. The Inner Planes were described simply as above (Earth, Fire, Water, Air, and what were then called the Positive and Negative Material Planes). The Ethereal Plane and Prime Material Plane

Prime Material Plane

The Prime Material Plane is the central plane of existence in the Dungeons & Dragons role-playing game...

 were also counted among their number.

In Dragon

Dragon (magazine)

Dragon is one of the two official magazines for source material for the Dungeons & Dragons role-playing game and associated products, the other being Dungeon. TSR, Inc. originally launched the monthly printed magazine in 1976 to succeed the company's earlier publication, The Strategic Review. The...

 #27 (July, 1979), Jeff Swycaffer suggested a far more expansive elemental scheme in which twelve new "elements" were proposed. The elements were envisioned here as a complex polyhedron

Polyhedron

In elementary geometry a polyhedron is a geometric solid in three dimensions with flat faces and straight edges...

 with 18 square sides and 8 triangular ones; a small rhombicuboctahedron. Four of the square sides represented Fire, Air, Earth, and Water. Between these elements were four qualities: Cold (between Air and Water), Moist (between Water and Earth), Hot (between Earth and Fire), and Dry (between Fire and Air). These elements and qualities formed an "equator" around the polyhedron, equidistant between the "poles" of Good and Evil. Between the equator and Good were placed the qualities Pleasure, Fertility, Beginning, and Light. Between the equator and Evil were placed the qualities Pain, Barren, Ending, and Dark.

In Dragon #32 (December 1979), in his column "From the Sorcerer's Scroll," Gygax said that Jeff Swycaffer's ideas "were good indeed," but noted that vapor should be substituted for moist and dust instead of dry/dryness.

So it was that in Deities & Demigods (1980), the "Para-Elemental Planes" were listed as:

• 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.

In 1983, The Land Beyond the Magic Mirror

The Land Beyond the Magic Mirror

The Land Beyond the Magic Mirror is an adventure module, written for use with the First Edition Advanced Dungeons & Dragons roleplaying game. It is set in the World of Greyhawk campaign setting.-Plot summary:...

 was the first place to feature a lightning quasielemental, although the description says they inhabit the Positive Energy Plane and the Elemental Plane of Air, indicating that Gygax didn't expect anyone to know what the Quasielemental Plane of Lightning was.

In Dragon #73 (May 1983), Gygax criticized the inner planar cosmology depicted in Deities & Demigods while taking sole responsibility for it.

Note that, in the torus, the Para-Elemental Planes (Ice, Dust, Vapor, Heat) occupy too much area. Discerning Students will also remark that three of these intervening planes are denoted by some material manifestation, while the remaining one is designated by a condition. Thus, the logical question: Which one in the series does not belong? Do not blame the Learned Authors of the work in which the depiction occurs — I am the one responsible for it, and I offer my apologies.

Getting back to the point of this article: Another reference illustration (Figure B, at right below), also from the DEITIES & DEMIGODS book, shows the Inner Planes (Material, Elemental, Positive, etc.). Isn’t it interesting to note how the Positive Material Plane sits upon the material multiverse as if it were a plate? Observe also how the Negative one serves as a saucer for the same body?

If these odd relationships have troubled you, Gentle Readers, half as much as they have disturbed me, you have been sorely put upon. I, for one, could stand it no longer.

After several hours of rooting around in the mess which I laughingly term my files, I discovered my notes on the Inner Planes. Atop the heap was an illustration of a tetrahedral structure for the Elemental Planes proposed by my Worthy Confederate, Steve Marsh. (count ‘em) Para-Elemental Planes, viz. Lightning, Magma, Dust, Ice, Vapor, and Ooze — all material substances, not conditions, by the by! The four faces are the Positive Material, Negative Material, and Shadow Planes, plus the infinity of the Prime.

After fiddling with this structure for some time, Gygax decided (as described in the same article in Dragon #73) to change the structure from a tetrahedron to a cube in which four of the six faces were the "Inner Planes" described in the Players Handbook: Earth, Fire, Air, Water, and the Negative and Positive Material Planes. The edges of the cube, where the various faces met, represented "Para-Elemental" and "Quasi-Elemental" planes. Gygax listed the Para-Elemental planes, where the elementals mingled, as Smoke (where Fire met Air), Ice (between Air and Water), Ooze (between Water and Earth) and Magma (between Earth and Fire). He listed the Quasi-Elemental planes as Lightning (between Air and the Positive Material Plane), Steam (between Water and the Positive Material Plane), Radiance (between Fire and the Positive Material Plane), Mineral (between Earth and the Positive Material Plane), Vacuum (between Air and the Negative Material Plane), Ash (between Fire and the Negative Material Plane), Salt (between Water and the Negative Material Plane), and Dust (between Earth and the Negative Energy Plane).

This new structure became the default one for the 1st and 2nd edition AD&D game, described in greater detail in the Manual of the Planes (1987), the Planescape campaign setting (1994), and The Inner Planes (1998). In his review of the Planescape Campaign Setting

Planescape Campaign Setting

The Planescape Campaign Setting was a boxed set for the Dungeons & Dragons fantasy role-playing game. The set was designed by David "Zeb" Cook and published in 1994, and introduced the Planescape setting.-Contents:...

 boxed set, Gene Alloway mentioned that the set gives players a solid sense of "the sheer force of nature that drives all the Inner Planes. The Inner Planes don't have anything against you - they're hard on everyone." The cosmology remained the same in all these sources, though in Planescape the Negative and Positive Material Planes were renamed the Negative and Positive Energy Planes.

In the 3rd edition Manual of the Planes (2001), the paraelemental and quasielemental planes were removed, and the Inner Planes were assumed, by default, to be completely separate and not border one another. Paraelemental creatures were said to exist in both their constituent planes. Later 3rd edition sources, such as Sandstorm (2005), generally did assume the Inner Planes bordered one another. The quasielemental planes were never mentioned in 3rd edition at all, although an article on the Plane of Radiance appeared in Dragon #321 as the antithesis of the Plane of Shadow rather than as a quasielemental plane.

In the 4th edition of the game, the Inner Planes were replaced with a plane called the Elemental Chaos, which combined features of the Inner Planes, the Ethereal Plane, and Limbo

Limbo (Dungeons & Dragons)

In Dungeons and Dragons, fantasy role-playing game, Limbo or more fully, the Ever-Changing Chaos of Limbo, is a chaotic neutral-aligned plane of existence...

, and also contained within it the Abyss

Abyss (Dungeons & Dragons)

In the Dungeons & Dragons fantasy role-playing game, the Abyss or more fully, the Infinite Layers of the Abyss, is a chaotic evil-aligned plane of existence. It is one of a number of alignment-based Outer Planes that form part of the standard Dungeons & Dragons cosmology, used in the Planescape...

. The Negative Energy Plane was combined with the Plane of Shadow and Ravenloft

Ravenloft

Ravenloft is a campaign setting for the Dungeons & Dragons roleplaying game. It is an alternate time-space existence known as a pocket dimension called the Demiplane of Dread, which consists of a collection of land pieces called domains brought together by a mysterious force known only as "The Dark...

 to form a plane called the Shadowfell.