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
The flow of time can vary greatly from one plane to another, planar travelers may spend years exploring one plane, only to return to their home plane where mere days, or even less, has elapsed since they left. These erratic time flows are most often employed by powerful arcanists of clerics, whom may depart their home plane in preference of another with a more suitable time flow. For example a powerful wizard could depart the Material plane in favor of a plane with the Flowing Time trait could spend years furthering his research, and later return to the Material plane to find that here, no significant amount of time has passed since his depature.

Normal Time: This is the standard rate of time, compared to the Material plane. One hour on any plane with this trait, equals one hour on the Material plane.

Flowing Time: Time on a plane with this trait either flows faster or slower than it does on the Material plane. How different the time flow is from the Material plane can be dramatic, for example the passing of a year on the Material plane may only equal one round on the Flowing Time plane, or vice versa.

Erratic Time: Some planes have time that slows down and speeds up, so an individual may lose or gain time as he moves between the two planes. To the denizens of such a plane, time flows naturally and these shifts in time pass unnoticed.

Timeless: Time still passes on planes with the Timeless trait, but the effects are diminished. Hunger, thirst and aging will not afflict inhabitants, or visitors, to the plane. In the same case, natural healing will not work and wounds suffered will not naturally regenerate, unless magical healing is used. If a plane is timeless with respect to magic, any spell cast with a noninstantaneous duration is permanent until dispelled. Timeless planes are dangerous to the unwary traveler, as effects such as thirst, hunger, and age may strike once the traveler leaves the plane - sometimes retroactively.

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.