Planar traits

The many planes in the cosmology of Toril had traits that greatly differentiated them from the Prime Material Plane with which most adventurers were familiar. Depending on your abilities, race, and even faith the different planes could be warm, welcoming places, or manifestations of pure horror.

In 1st and 2nd edition D&D, planes were not categorized by specific traits but instead were described in terms of survival: breathing, time, food and drink, gravity, direction, vision and senses, and movement. Third edition codified the various survival factors into "physical traits" and added traits relating to the elemental planes, alignment, and magic. In addition to those four categories, the Forgotten Realms World Tree cosmology added a "faith trait" that, for some planes, replaced the alignment trait.


 * Physical Traits: set the laws of nature, including gravity and time.
 * Elemental and Energy Traits: determined the dominance of particular elemental or energy forces.
 * Alignment Traits: described the strength or weakness of moral (good/evil) and ethical (lawful/chaotic) forces permeating a plane.
 * Magic Traits: described the efficacy, predictability, difficulty, and magnitude of magical effects.
 * Faith Trait: the degree to which non-believers, heretics, and infidels (relative to the deity or deities that inhabit the plane) were hindered when performing certain skills or interacting with the inhabitants of the plane.

Physical Traits
The physical traits of a plane were the "natural" laws of the plane, the size and shape (if not infinite), the malleability of matter, the strength and direction of gravity, the flow of time with respect to the other planes, the boundaries (if any), and borders with other planes.

Gravity
If gravity operated on a plane, it might have been constant or had varying strength and direction. The types of gravity traits were:


 * Normal Gravity: The majority of planes had gravity nearly identical to that of the Prime Material Plane. Travelers noticed no difference in physical abilities, encumbrance, or carrying capacity.


 * Heavy Gravity: A visitor and all her equipment effectively doubled in weight upon entering a plane with intense gravity, increasing encumbrance with a likely reduction in speed. Essentially all physical activity and skills were more difficult and ranged weapons only reached half as far. Falling caused sixty six percent more damage on average than falls in normal gravity.


 * Light Gravity: A visitor and all his equipment were effectively halved in weight, which allowed him to lift and carry more but tended to throw his balance off. Most physical activity and skills were made more difficult by this sudden change in equilibrium except for jumping and climbing. Ranged weapons could reach twice as far. Falling caused thirty three percent less damage on average than falls in normal gravity.


 * No Gravity: Objects and individuals floated in space with no discernible up or down unless acted upon by other forces such as magic&mdash;a fly spell for example. In some planes, the power of movement could be derived from consciousness itself and was directed by "force of will": a being desired to travel in a particular direction and willed it to happen. Mass, momentum, and friction still applied to objects in the usual fashion but without the effect of gravity.


 * Objective Directional Gravity: A visitor to a plane with this gravity trait experienced the familiar pull of normal gravity but not necessarily perpendicular to the ground or a particular surface. Direction could be at any angle with respect to a surface and this could be a local or global phenomenon. For example, if gravity pulled at a forty five degree angle to the ground, visitors would feel as if they were on the side of a steep mountain with no base or peak. If gravity pulled perpendicular to all surfaces, a traveler could walk on all sides of a cube floating in space, or on the floor, walls, and ceiling of a room. Shifts in direction could be abrupt so visitors were cautioned to beware a long hallway doesn't suddenly turn into a vertical shaft.


 * Subjective Directional Gravity: This gravity trait was probably the most disorientating to non-native beings because gravity existed only for sentient creatures and pulled with normal force in the direction each individual chose. Inanimate objects and non-sentient creatures were essentially in zero gravity. Those without the ability to fly had to pick a direction to call "down" and fall in a straight line until a different direction was chosen. Coming to a stop or a soft landing was accomplished by reversing the direction of "down" to slow movement rate. Only the very wise could do this fairly reliably without concentration. Once on a surface, most visitors found it relatively easy to imagine "down" toward their feet and could move about normally.

Time
Time could flow at greatly different rates from one plane to another: faster, slower, or effectively stopped with respect to certain aspects of life and magic. It is important to note that the rate of time always seemed to flow normally for the planar traveler&mdash;a month in another plane felt like a month regardless of changing planar conditions or what happened when she returned. The types of time traits were:


 * Normal Time: The majority of planes had the same rate of time flow as on the Prime Material Plane.


 * Flowing Time: Time on a plane with this trait flowed either faster or slower than on the Material plane, and the rates could be dramatically different. A planar traveler might spend a year exploring one plane and upon returning to her home plane discover that only a few seconds had passed since she left. Likewise, a traveler might depart his small village on the Prime Material plane for a day and come back to a thriving metropolis with a stable where his house used to be.


 * Erratic Time: This trait indicated that the flow of time on a plane sped up or slowed down at random intervals. A traveler could unknowingly gain or lose time when transitioning to a different plane or back to his or her home plane.


 * Timeless: A plane with this trait effectively stopped or paused some of the effects of time with respect to life conditions and/or magic. Hunger, thirst, and such processes as disease, poison, healing, and aging might be halted while a traveler is in a timeless plane. If natural healing was affected, only magic could be used to close wounds and repair damage. If a plane was timeless with respect to magic, only spells with instantaneous duration acted as normal, all others were permanent until dispelled. Spending large amounts of time on a plane with this trait was risky because when a traveler returned to a plane with a normal flow of time the effects that were halted suddenly took effect retroactively. Instant aging, severe malnutrition and hunger, or rapid disease progression could really ruin your day.

Shape and Size
In 1st and 2nd edition D&D the Inner and Outer planes of the Great Wheel cosmology were all infinite in size. Only the demiplanes had a finite size and a distinct shape. In the World Tree cosmology model, only the plane of Cynosure was finite. After the Spellplague the Astral dominions were set adrift in the Astral Sea and though vast, were finite in size. The size and shape traits that could be used to describe planes of existence were:


 * Infinite: Stretching out forever in at least one dimension, an infinite plane could contain finite chunks of matter, like planets for example.


 * Finite: A finite plane had definite edges, either barriers such as walls or borders with other planes. Demiplanes were usually finite.


 * Self-Contained: A plane with this trait was circular in some fashion, wrapping around on itself so that traveling in any direction eventually brought you back to the same spot. This could be due to geometry, like a cubic, spherical, or toroidal plane, or due to magic teleportation from one edge to the opposite edge.

Morphic Traits
The matter that made up planes could be manipulated by various means, or not at all. The types of morphic traits were:


 * Alterable Morphic: Planes with this trait were most like the Prime Material Plane. Matter stayed in place unless acted upon by a physical force or magic only. Work of some sort was required to produce physical changes in the environment.


 * Static: Inhabitants of a static plane and their possessions were untouchable by outside visitors, as if they were surrounded by an aura of invulnerability or under the effect of a time stop spell. Magic spells had no effect unless the static trait could be suspended or suppressed somehow. Matter not within the aura of a living resident could only be moved by a feat of strength, if at all.


 * Highly Morphic: Matter on this type of plane changed form, nature, and location easily, either reacting to magical spells, force of will, or the mere thought of a sentient being. Indeed, it often required great effort or concentration to keep a given area stable for a length of time as the substance of the plane seemed to transform of its own volition.


 * Magically Morphic: The fundamental matter of a plane with this trait could be manipulated with spells specifically designed to do so. Shadow evocation is an example of a spell designed to modify the base material of the Plane of Shadow.


 * Divinely Morphic: Planes with this trait were Alterable Morphic to ordinary visitors but deities and beings of great power could instantly manipulate the landscape, objects, and creatures that fell within their area of influence with dramatic results.


 * Sentient: A plane that is under complete control of its own consciousness. Travelers that caught the attention of the overmind were presented with a landscape or environment that changed on a whim, becoming more or less hostile depending on the impressions of a vast, inscrutable, and alien awareness.

Alignment Traits
Powerful entities like deities or demon lords directly affect the alignment traits of the planes they inhabit, and such planes will be inhospitable to travelers of opposing alignments.