How can you possibly have a fantasy without magic? Some authors - like Tolkien - leave their magic as an interesting but largely unexplained part of the story, while others - like Jordan - work out a comprehensive and usually consistent system of magic. If you want to tell any of your story from the point of view of a magic-user, you have to take the second option. This essay is, if you like, a guide on how to do it, using four separate systems from fantasy series as examples.
When working out your magical system, you have to ask yourself several questions.
Who can use it? Can anyone work magic, anyone who is taught, only someone who is born with the talent? Is it a clear division between can and can't, or a continuum of increasing difficulty? If people are born with it, is it genetic, is it divinely bestowed, is it random? Do magic-users vary in strength and/or skill? What causes this variation? Is there more than one type of magic, or just different ways of using it?
Jordan's system is fairly clear, or at least the One Power; a minority can use it, it's genetic, a clear division, users vary (reasons unexplained, possibly genetic) men and women use magic differently but the basis is the same. The True Power we know less about, other than that it is available to both men and women in the same way, and it is granted by the Dark One. Talents like Dreaming, Foretelling etc are also clearly divided, and probably controlled by the Pattern.
David Eddings' system of the Will and the Word is vaguer; a very small minority can work magic and they do vary. Exactly who can use it is uncertain, but to some degree at least it seems to be hereditary.
Eddings' other magical system, in the Sparhawk series, relies on spells and incantations; anyone can use it if they can master the spells (and have a deity to call on). Skill depends on how long you've been practising.
Melanie Rawn's Sunrunner series has a neatly worked out system; there are two types of magic, one determined by a recessive gene, one by a dominant. It's like the One Power in that most have to be taught, but some work it out on their own. It is possible to have both genes and thus use both types. Variation in strength and skill is probably genetic also, as it seems to run in families.
What's the basis for it? This is the important one; where does magic come from? Is it a talent like telepathy? Energy drawn from the environment or from some other source? A gift granted by deities? How is it used?
One Power: drawn from the True Source and manipulated by those with the ability. Will and Word: power of mind and will, released by the spoken word. Sparhawk: granted by deities, but only if you ask nicely enough. Sunrunner; sunlight, moonlight and starlight are used to project your mind to communicate or to view faraway events; jewels also store power, and mirrors can be used in the same way as light sources. Colour is important and each person has a unique set of mental colours.
What can you do with it? Now that's what everyone wants to know. What limits are there? What kinds of things can you do with magic? What can't you do? Does it vary between people or between different types of magic (assuming there are different types)?
One Power: a lot of things. You can manipulate the physical environment. You can manipulate other people's minds and bodies. You can create illusions. You can build wards as barriers or warning signals. You can travel rapidly by taking shortcuts through spacetime. You can foretell the future, although not under your control, and enter and alter people's dreams, although that's a separate type of magic. You can't heal yourself, lift yourself, or probably use the Power directly on yourself at all. You can't make multiple-purpose wards. You can't raise the dead. Men and women can each do some things the other can't, but in general can produce the same results using different methods. Some people do not have the strength or skill to accomplish some tasks.
Will and Word: You can do almost anything you can imagine, including defy the laws of physics. If you're dealing with demons or deities it becomes more complex. You cannot unmake anything; that is the one unbreakable rule, and any attempt to break it will unmake you. Unmaking is defined as willing something out of existence.
Sparhawk: again, you can do almost anything, but a spell is in essence an appeal to a deity to do something for you and there's no rule that says they have to do it. The different deities and thus the different disciplines of magic work in different ways (for example, the Delphae make themselves invisible by bending light, whereas Aphrael does it by altering the minds of the people she doesn't want to see her).
Sunrunner: Think of it as an out-of-body experience. Basically, your mind is carried on the light to wherever you want to go, as long as that place can be reached by light. You can see everything as you would if you were flying. You can talk to others, both faradhi and diarmadhi (the two types of magic). Mirrors can be used to communicate with someone who has a matching mirror, to view events through, to tell whether a given person is gifted or not, and to catch someone's soul. Some mirror spells will only work if the user is diarmadhi. Jewels absorb power from their wearer and can be used in various spells; colours are important. You can manipulate the elements; earth, air, fire and water, but particularly fire.
Can magic-users combine power? If one person isn't strong enough to do something, can he/she join forces with someone else to do it?
One Power: yes, but only in certain combinations. Any number up to seventy-two, but only some balances of men and women. The strength of a linked circle is less than the sum of the individual strengths of its members.
Will and Word: yes. It's a mental link, and there don't seem to be any limits.
Sparhawk: as far as I know, no.
Sunrunner: yes. Any number can link, multiples of three being particularly strong. Faradhi and diarmadhi can link together; balance doesn't seem to be important except in one case, that being that a group containing three or more diarmadhi is protected from the effects of iron. (See the section on side effects)
Is there any way to artificially increase strength?
Both Eddings systems: no. One Power yes, using angreal and sa'angreal which will increase the amount of the Power you can hold by a given amount. Sunrunner yes, by taking the herb dranath (which is dangerous and addictive).
What side-effects are there to using magic? What disadvantages does a magic-user have that normal people do not? What advantages other than the ability itself? What can happen if magic is misused?
One Power: channelers, but not non-channelers, can be forcibly turned to the Shadow or bound using an Oath Rod. Channelers can be severed from the Power, or can be burned out by trying to draw too much of it, and death usually results. Male channelers are eventually driven mad or killed by the taint. On the good side, channelers live much longer than normal people, they seem to be healthier, and they have the ability to bond Warders.
Will and Word: magic-users are essentially immortal. There are no obvious disadvantages, but it may be possible to burn yourself out with overuse.
Sparhawk: several magic-users are known to have lived a very long time, but whether this is automatic, a matter of using magic to rejuvenate yourself, or due to divine favour is uncertain. Again, there are no obvious disadvantages.
Sunrunner: only one advantage, occasional glimpses of the future through
dreams and visions. The disadvantages, on the other hand - Faradhi suffer
extreme seasickness, diarmadhi are vulnerable to the 'Shadowcatcher'
mirror spell, piercing the flesh of either with iron while working magic
will result in intense pain, and in the case of faradhi death.
If you're not familiar with one or more of the series I've described here, then they are:
The Wheel Of Time by Robert Jordan is still being written, and so far consists of eight books with at least three more expected. The eight are in order The Eye of the World, The Great Hunt, The Dragon Reborn, The Shadow Rising, The Fires of Heaven, Lord of Chaos, A Crown Of Swords and The Path Of Daggers. Set in the same world is a novella, New Spring, which is part of the Legends anthology, and an illustrated guide entitled The World of Robert Jordan's The Wheel Of Time, but generally called the Guide.
David Eddings has created two separate magical worlds. The first is the setting of two series - the Belgariad and the Malloreon - plus two prequels. The Belgariad consists of Pawn of Prophecy, Queen of Sorcery, Magician's Gambit, Castle of Wizardry and Enchanter's End Game. The Malloreon consists of Guardians of the West, King of the Murgos, Demon Lord of Karanda, Sorceress of Darshiva and Seeress of Kell. The prequels are Belgarath the Sorcerer and Polgara the Sorceress. The preliminary notes for this world are also published under the title The Rivan Codex.
Eddings' other world is the setting for the Elenium and the Tamuli. The Elenium is The Diamond Throne, The Ruby Knight and The Sapphire Rose. The Tamuli is Domes of Fire, The Shining Ones and The Hidden City.
Melanie Rawn's two trilogies are set in the same world. The Dragon Prince books are The Dragon Prince, The Star Scroll and Sunrunner's Fire. The Dragon Star books are Stronghold, The Dragon Token and Skybowl.