Magic

The term Magic has two related meanings. First, it refers to a supernatural force or energy described as "the essence of life and creation." Second, it refers to the practice of harnessing this force to produce changes in reality. This practice is sometimes also referred to as The Art. An act of magic is called a spell, and the act of performing such an act is called casting. Most supernatural beings are capable of performing magic, as are some mortals, who are referred to as practitioners.

Magic as energy
According to Harry Dresden, magic is life's essence; generated by living things, and may be thought of as akin to the concepts of Odic force and prana. The human heart, soul and emotions are also powerful sources of magical energy. Black magic comes from negative emotions like lust, fear and anger, which are easy to harness. Dresden claims his own magic is both more difficult to perform and more powerful because it comes from a deeper, truer, and purer source.

Magic exists as a sort of energy field which encompasses the entire Earth.. The intensity of this field is the same at all points, because magical energy flows near instantaneously. When a spell is cast, it doesn't deplete the local supply of magic, but rather causes a decrease in the strength of the field worldwide. However, it is possible to isolate a limited area from the global field, which limits the amount of magic available in that area. In Small Favor, the Denarians used a large pantacle to isolate Shedd Aquarium. As the site was the location of an intense magical battle, the magical energy was eventually entirely depleted, making it impossible to cast any spells. Once the pentacle was removed, however, magical energy flooded back into the area.

Magic as skill
Similar to using firearms, casting spells is a three-step process; gathering energy, shaping it with one's thoughts and feelings, releasing it in the intended direction. In Blood Rites, Dresden remarks that it can be very difficult for a single individual to handle all these tasks when performing a large spell, so that three practitioners will work in concert to divide the effort.

Practitioners must be confident in their ability and in their motivation in casting a spell; believing that one is unable to do it, or that it's not right to do it, will preclude him from using that spell.

As a side-effect, magic interferes with the operation of electrical or electronic devices; its severity depending on the complexity of the device and the amount of ambient magic. Although the term "interference" suggests that the effect is temporary, exposure to magic can and often does produce permanent damage to affected devices. Waldo Butters describes it an intensification of Murphy's Law. This previously manifested in such ways as causing dairy products to spoil and warts and boils to appear on human skin.

According to Ebenezar McCoy, this phenomenon is caused by the inner conflict of human beings and the resulting magical turbulence; Faerie magic does not harm machinery. Or, more simply, magic is interwoven in Faeries in a different way than mortals, so the side effects are different. According to Waldo Butters, wizards are surrounded by a "murphyonic field", closely linked to their healing powers. As a consequence, Dresden often hexes, knowingly or unknowingly, computers, electrical material, and other machinery.

In a spell, energy flows from the left, where energy is provided, to the right, where energy is released. Also, the left hand is the proper hand to carry a staff.

Practitioners
Practitioner is a generic term for an individual who can use magic, with no reference to the user's power or skill. There are a number of other terms, however, which do have such connotations. Most human beings cannot use magic at all, and the percentage of practitioners diminishes with the increase in the power they can command.
 * Wizards are practitioners who show the full spectrum of magical abilities known to mortals, and are therefore usually members of the White Council. The Council grants membership only to the top two percent most powerful human practitioners. Yet, even the strongest wizards are insignificant with respect to supernatural heavyweights like the Faerie Queen; very few exceptions, such as The Original Merlin, exist.
 * Sorcerers are practitioners whose skills lie primarily in destructive magic, "someone who can do some serious violence with magic" as Dresden puts it. While every Wizard is a Sorcerer, not every Sorcerer is a Wizard, so the term is sometimes used as a pejorative, with the connotation of a dangerous or destructive individual.
 * Minor talents are practitioners with a small magical ability.
 * Warlocks are practitioners who have violated one of the laws of magic.

In addition to the ability to work magic, practitioners also have an extraordinary ability to recover from injury. They do not heal more quickly than mortals, but they do heal better and more completely. With enough time, a practitioner can recover from injuries which would be permanently disabling to an ordinary person. Furthermore, the recovery is eventually so complete that sometimes there is no evidence that an injury ever occurred, even to the extend of repairing scar tissue. This enhanced healing also slows down the aging process and greatly prolongs a practitioner's life, allowing Wizards of the White Council to live for three hundred or four hundred years.

In much the same way that people have varying talents for art, science, or music, practitioners have varying aptitudes for different aspects of magic. Harry Dresden is very adept at thaumaturgy (particularly at finding things), but less so at evocation. His apprentice Molly Carpenter, on the other hand, has a knack for veils and psychomancy.

The Seven Laws of Magic
The Laws of Magic are a set of rules of the White Council regulating the use of magic by wizards and practitioners. They are intended to prevent the abuse of magic, and protect both practitioners and mortals from harmful magic. The White Council enforces the Laws not only on its own members, but on all human magical practitioners. The punishment for violating the Laws is most often death.
 * 1) Thou shalt not kill.
 * 2) Thou shalt not transform others.
 * 3) Thou shalt not invade the mind of another.
 * 4) Thou shalt not enthrall another.
 * 5) Thou shalt not reach beyond the borders of life.
 * 6) Thou shalt not swim against the currents of Time.
 * 7) Thou shalt not seek knowledge beyond the Outer Gates.

Storm Front
In Storm Front, Harry Dresden is angry and nauseated that someone would use a thing of beauty like magic and use it to hurt, kill and destroy when magic taps into the energies of creation.

Fool Moon
In Fool Moon,

Grave Peril
In Grave Peril,

Summer Knight
In Summer Knight,

Death Masks
In Death Masks,

Blood Rites
In Blood Rites: Harry Dresden was hired by Arturo Genosa to stop Strega from killing with a Malocchio—an Entropy curse. Murphy asked Dresden why he can't do the sunshine magic thing like he did on Bianca St. Claire a few years back. Dresden said that he tried it again after The War and found out that he needed to be genuinely happy to be able to fold sunshine into a hankie or it does not work.

Dead Beat
In Dead Beat,

Proven Guilty
In Proven Guilty,

White Night
In White Night,

Small Favor
In Small Favor,

The Warrior
In The Warrior,

Turn Coat
In Turn Coat, Anastasia Luccio told Harry Dresden how his mother, Margaret LeFay, loved pointing out the ares of "grey" magic, as she called it and questioned their legitimacy. As a consequence, the Senior Council tasked the Wardens with keeping an eye on her.

Changes
In Changes, Harry Dresden performed magic in his mind without the use of any props while immobilized after having broken his back and being desperate to rescue his daughter. He first summoned Uriel who could not help him; he then summoned Mab.

Ghost Story
In Ghost Story, Harry Dresden tries to figure out how to use magic being a ghost. He had to access the energy, empower the spell with memories. "Working magic as a ghost was all about doing it au natural." With a tracking spell to find Molly Carpenter, at first he kept finding himself at some place they were at long ago. When he used a current memory and filled it with details, it worked.

Cold Days
In Cold Days,

Word of Jim
According to Jim Butcher, "Magic wasn't always screwing up post-WW2 tech. Before WW2 magic had other effects. It sorta changes slowly over time, and about every 3 centuries it rolls over into something else. At one time, instead of magic making machines flip out it made cream go bad. Before that magic made weird moles on your skin and fire would burn slightly different colors when you were around it."