Note: This article was written when AD&D was the game-du-jour. Some of its concepts are outmoded now that the campaign world has been converted to 3rd (and now 4th) edition D&D.
The four basic methods to invoke magical effects are known as Spell, Rune, Voice, and Psionic magic. Each is different, yet all four use the same enigmatic matter/energy form known as mana. Mana is created and required by all forms of life and is in constant motion with the surrounding world. For the purposes of this document, the term “Spell” refers to a magical effect which relies on a supply of extra-planar energy to function. This is, by far, the most plentiful and simplest form of magic.
When the gods first established the twenty worlds, they had to ensure the level of mana in each of the worlds would be sufficient to allow for magical invocations of some sort. On the prime world, a "wall around the world" was constructed to concentrate the mana in one relatively small region. This thousand-foot tall “waterfall” brings mana from the outside world into the prime world. The effect is to decrease the overall mana level outside the wall, yet make the inner world very rich in magic of all types. (See Cosmos). Since mana is very difficult to manipulate, wizards over the millennia have developed forms of magic that use as little of this potent energy as possible.
A brief overview of the types of magic follows:
By a simple mind exercise (reminiscent of psionic magic), a weakening between the plane the user is on and the energy planes is accomplished. Energy is then siphoned from those planes, through the users body, and then (via the gestures, incantations, and materials), into the desired effect.
The limitations are obvious: First of all, since the invocation involves extra-planar activity, there exists the possibility of attracting attention from not only other-worldly beings, but also of spell-users on the plane of origin. Secondly, since the users body is the focus for the energy, damage could result from over-use. (However, since the energy is only siphoned via the mental triggering effect, it is quite easy for an out-of-control user to abort the invocation at any time).
The main advantage to spell magic is simplicity. Since only a small amount of mana is needed to invoke the cross-planar siphoning, it is a significantly easier skill to learn than Rune, Voice, and Psionic magic. While an intelligent person can learn basic spell magic over the course of a few years, most cannot fathom Rune, Voice, or Psionic magic – ever!
By aligning material in a certain way (depending on the material and the desired effect), the desired mana flow is channeled through the material to invoke an effect. The necessary requirements on the materials and structure cause for a certain frailty to this type of magic, however the separation from the human conductor concept allows for much more powerful invocations to be accomplished. All magic items are based (to at least a minor degree) on Rune magic in that they must be aligned in such a way so as to hold an enchantment. Thus, a spell- magic sword actually has a rune-magic invocation which allows the spell to remain in effect indefinitely. Also, alchemical enchantments such as potions are a limited form of rune magic.
Voice magic (in its simplest terms) is a specific version of Rune magic. By vibrating (aligning) the air in a specific manner, magical effects are invoked. The most common of these invocations are offensive in nature and generally involve hitting a target with a concentrated blast of air or some other material. Voice magic is slightly easier than Rune magic, but is limited to quick, non-complex invocations. Voice magic is also the only known magic to occasionally be invoked by nature. Certain times, for example, the wind will howl through mountains making such a sound as to invoke a magical effect. Usually, these natural magics take the form of enormous visual displays similar to the Aurora Borealis on Earth.
This is another specific version of Rune magic in that the magical effects are invoked when the brain is structured in a certain way and a triggering thought process is done. However, this magic is also unique in that the body and mind are used as a gateway for the energies. Unlike spell magic, though, this energy is not siphoned off of another plane, but instead comes from mana. Thus, psionic magic is a combination of Rune and Spell magic, where pure mana is funneled through the user instead of siphoned energy.
The limitations are clear. Mana is very powerful and control can easily be lost. Unlike spell magic, though, there is no trigger effect to control the energy. If an invocation goes astray, the user could be severely damaged. Combat using psionic magic is also very specific. Offensive maneuvers using this style are almost exclusively based on overloading the sensitive patterns within another psionics mind. Thus, a non-psionic faces little threat from a psionic attack. [A terrestrial analogy would be electricity: A small electric current can do tremendous damage to electronic devices such as computers, while that same amount can do no damage at all to a non-electronic device, such as a person. However, a large current can easily damage a person.]
Detect Magic – This invocation simply detects weak spots between the user's plane and the energy planes. It registers the intensity of the energy being siphoned, as well as showing the form of that energy in this plane. This latter feature is how experienced wizards can determine the nature of a magic item or spell. Note that since this invocation detects weaknesses between the energy planes and the user's plane, its use (like that of all spell magic) on other planes is dependent on their proximity to the energy planes.
Dispel Magic – This invocation patches over weak spots between the energy planes and the local area. Since it stops the flow of energy, it disrupts spells likewise. Note that this invocation has no effect whatsoever on the mana level and so does not affect any of the other types of magics. Some types of spell-invocations have built-in safeguards where another trigger effect is automatically started when the siphoned energy stops. Thus, the spell is only inactive for a short period of time.
Identify – This invocation is essentially a fine-tuned detect magic. It allows experienced wizards to examine in detail the exact specifications of siphoned energies. It has no effect on mana-based magic.
Detect Mana – This invocation registers the level of mana in an area. Note that when used on a spell-magic invocation, it may register an identical level for widely different power levels since mana is used only as a trigger.
Dispel Mana – This complex (and extremely difficult) invocation removes all mana from an area. The most common method is to use up the mana very quickly (such as with a infinite progression power siphon). This will cause the entire area to be devoid of mana for a few moments (until replenished by the flow). During the mana-crisis on Earth after the gods fled, this drain was of a permanent nature and so was not used unless absolutely necessary. Note also that spell-magic uses only a minor trigger effect and once it is in effect, the siphoned energy keeps the spell active. Thus, if the mana is removed, spell magics already active will be unaffected, though new spells cannot be cast until the mana is replenished.
Magic Suppression – This invocation constricts the flow of siphoned energy to an area. Thus, most spell-based magic will fail to work in that area. Even the “protected” types of magic with re-triggering will fail to work because the area will not let any extra-planar energy through. This is a very dangerous effect for spell-users, but presents no threat to mana-users (such as psionics).
Underdark Magic Items – The dark elves are quite fluent with rune magic and use it frequently to construct their “magical” daggers, swords, and cloaks. These items, being based on Rune magic, do not register on a detect magic and cannot be dispelled. It is rumored that some Drow know Voice magic as well. Since sunlight has a decaying effect on the materials used, these items cannot be exposed to sunlight or else the delicate alignment is ruined and the magic will not be invoked.
By using too much mana too quickly, the mana in an area can be depleted. Most of the time, the mana is restored to an area from the mana flow while the invocation is active. However, occasionally, very powerful mana-wizards have generated enormous invocations that have depleted the mana in an area for several seconds or minutes. (Persistent rumors exist about wizards who brought forth such a great magic that the area's mana was depleted for over a week. These tales, however, are dismissed by learned mana-masters).
The mana flow is simply the flow of mana from one place to another. What is unusual about it, though, is that it follows specific patterns based on terrain. Weather causes some variation, though this is usually negligible. The end result is a web-like pattern of mana intensity all over the globe. Where the lines of the web cross, the mana is rich. Between the lines, the mana is weaker. With very few exceptions, there is no place on the prime world where the mana is too weak to cast a spell-magic trigger. Thus, spells works without variation worldwide. Mana-based magic, though, is sensitive to this flow and some powerful invocations may not work in the shallow “troughs” of this web.
Outside the physical plane of existence is, among other things, a dimension called "The Elemental World". This is not a planet as we know the it, but instead an enormous storehouse for the six elements: the four physical elements (Air, Earth, Fire, and Water) and the two spiritual elements (Positive and Negative, also called Good and Evil). Underlying these six elements is a special mixture of all which is called Shadow. Next to the spiritual elements, the physical elements are rather insignificant, so when combined they do not assert themselves as do positive and negative energy. During his battle with the Godslayer, Lord Ozzie powered himself up by siphoning off energies from the positive and negative planes – an ability given to him by the Shadowlord. However, to rise to the level of the Godslayer, Ozzie had to drain an enormous amount of energy very quickly. This left a void on the elemental world into which Shadow was able to move. It is now believed that The Shadowlord planned for this scenario all along. It is not known, however, how he knew that Lord Ozzie would come to need that much power.
Back on the "prime world", the elemental energies played a key role in the nature of magic. The energies are the power behind almost all magic known to wizards. Another power source, called mana, exists, but is much harder to manipulate. In order to use elemental energy, though, a magician must tap into a small amount of mana to draw in the required amount of energy. This is called the “trigger spell” and is the first skill taught to apprentice magicians. It is perhaps the most difficult skill to grasp and is quite probably the cause of most spell failures. Compared to mana, using elemental energy is trivial. Almost all magic, therefore, is based on the following two-step process: 1) Use mana as the trigger spell to draw in a certain amount of a certain type of elemental energy and 2) Manipulate that energy to produce the desired effect.
The problem seemed to arise when the elements were replaced by shadow. Suddenly, when a wizard needed two parts fire and one part water, he got three parts shadow! Even though every ounce of energy would still be available, it would not produce the desired effect. However, within a month of Shadow's takeover of the Elements, energies summoned from the elemental world returned to their normal state. Instead of three parts shadow in the above example, the wizard would get two parts fire and one part water.1)
However, this did not seem to solve the problem and wizards around the world continued to struggle with their spells. In late March, 1109, the Council of Wizards convened for the first time since the change and discussed what had happened. While no real understanding of the change was agreed upon, an edict was issued which stated (in part) that “The magic change appears permanent and that all spellcasters should learn a new Trigger Spell”. However, since no details of this new Trigger spell were supplied, the membership has been left to fend for themselves.
Many magicians have been unable to do the required research to replace their spells and so have effectively lost their powers. In addition, many magic items used the same two-step process and so have been altered irrevocably. The frustrating thing is that they remain magical at the same level that they were before, but they no longer do what they did!
Mana itself remains unaffected by the Shadowlord's takeover and so any magic that used mana exclusively is just as potent as it was before January, 1108. Psionic powers and certain artifacts are the best examples of this situation.