The Three Orientations of Magic

Magic in fantasy literature and fantasy games usually falls into one of three categories: caster oriented, environment oriented, or object oriented. Within these three categories there are other, more technical, categories. Magic systems are usually combinations of 1 to 3 of these technical categories. AD&D magic, for example, combines the styles of Verse (Verbal), Body Movement (Somatic), and Sympathetic (Material).

This is not a complete list. Use it to help you come up with new Ways for the various races and worlds your players encounter.

Caster Oriented

Verse
Many forms of literary magic involve poetry. While the verses usually rhyme, they do not have to. A Japanese Way that uses Haiku might make an interesting magic system for an Oriental campaign, as would an Irish magic based on limericks (”A young, Kentish fighter named Rob, fought a priest from the temple of Bob…”) A very strange Way of this type might be to use anagrams . “Go to Sleep” becomes “Goose Pelt.”
Mathematics
Some more esoteric forms of magic use mathematical symbols and notation to unleash the force of magic. The knowledge of mathematical formulae allow the wizard to create and control magic. Sometimes, specific formulae must be recited to cast a spell. See the Piers Anthony’s Magic of Xanth for an example of this.
Music
In many cultures, song and melodies have a lot to do with controlling the forces of magic. See, for example, the Battle Dancers in Dragon #159 , and also Charles deLint’s Celtic fantasy, Moonheart.
Body Movement
Almost all forms of magic in fantasy role-playing games require the use of specific bodily motions to unleash magic. This can be as simple as hand movements and as complex as ritual dance. In any case, if the wizard is tied, very few spells can be cast. The use of body movement in the form of dances, and in conjunction with Music, is a common form of magic in history. The rain dances of the American Indian are one example of this.
Innate Power
In some stories, magic is very similar to what is often called psionics. Magic, or the ability to unleash and control it, is an innate ability of the caster. If you are born with it, you need training to use it, but if you aren’t born with it, no training will let you use it. When magic is specifically innate, it rarely requires material components, although it will sometimes require verbalization. One way to balance the lack of verbal, somatic, or material components with an innate Way is through specific weaknesses. You might decide that iron or lead dampens the power of these wizards.
Power Words
In some systems of magic, power is gained through the knowledge of specific power words and syllables. Often (and preferable from a game standpoint), knowledge of how to use the words is also required. The Bene Geserit of Frank Herbert’s Dune series use a form of this.

Environment Oriented

Events
In many forms of fantasy magic, there are powerful spells that can only be cast at certain times or during certain special events. A certain spell might only be able to be cast during a full moon, an eclipse, a thunderstorm, or on the day after a white stag crosses Dog River.
General Locales
There are rare spell systems where certain spells can only be cast in certain areas, depending on the type of spell. Nature spells can only be cast in a non-urban area. Other spells can only be cast on the ocean, or on a mountain. Some might only be able to be cast in the Kingdom of Ierendi, or in the Elven Forest.
Places of Power
In certain stories, some areas are ‘magic rich’ and some are ‘magic poor.’ More powerful (higher level) spells can only be cast in areas especially rich in magical energies. Places where the magical energies are very strong will be coveted by powerful wizards. See Robert Lynn Asprin’s Myth Adventures series for an example of this. Often, this involves the use of magic lines of force, or Ley Lines. Some Greek priest magic required the use of specific groves for the priests to cast their spells.

Object Oriented

Symbolic/Runic
Symbols hold power. Runes or geometric designs allow wizards to work magic. The hex symbols (which are actually protections against magic) often seen on rural farmhouses in the eastern United States are an example of this. The Celtic system I provided earlier relies heavily upon runes.
Chemical
Alchemy is the road to magic in some books. Magic is activated through mixing various ingredients, into potions, salves, cauldrons, acids, etc. See The Worm of Aledorn , in Dragon #150 , for an example of this.
Specific Action
In some forms of magic, the caster has to perform very specifically designed actions. A sacrifice might be required for certain spells, and a different ritual for others. The wizard or priest may actually have to perform small tasks to gain each spell. This type of magic is most often associated with priests, who must petition their deities in specific ways.
Sympathetic
Most historical magic is, in some sense, sympathetic. That is, the spellcaster either does something similar to the desired result, such as taunting an opponent to get them angry, or uses something related to the desired result. Voodoo dolls are the best example of this. In AD&D, the use of grasshopper legs for a jump spell is another example of sympathetic magic.
Specific Item
There are very specific items which allow wizards to create magic. The Philosophers’ Stone was sought after in history as a means of transmuting metals. As another example, crystals could form the basis of magic on a world. Different crystals are required to cast different spells.
Mechanical
Magic can be created and controlled through the use of mechanical devices. Valves direct the flow of magical energy through systems of cogs and flywheels. This sounds similar to what Krynnish Gnomes might devise. Heaven save us from Gnomish wizards! Also, the magic of the Astrotech Rim is a mechanical magic.
Creature
In order to cast spells, the wizard must bind a specific creature to do the spell. A light spell might require that the caster bind a small fairy creature to create the light. More powerful spells will require that an outer-planar creature be bound to the caster’s wishes.
Naming
In Naming magic systems, it is assumed that everyone and everything has a secret, true name. Knowledge of the name gives the wizard power over the item or creature. The Norse mythology used the concept of true names quite heavily.
Divinity/Entity
The caster invokes extra-dimensional or extra-planar entities when casting spells. AD&Dclerical magic uses this—when the priest memorizes spells, the priest petitions a deity for those spells.