Seven Laws of Magic

The Laws are as follows:

1. Thou shalt not kill by use of magic. Wizards of the White Council are forbidden to kill human beings through the use of their power. This is the Law that Harry broke in killing his mentor, Justin DuMorne (Justin Morningway, in the television series). Self-defense is very occasionally allowed as a mitigating factor. This Law is also a primary reason Wardens wield swords. Several times throughout the series, Wardens have fought to kill with magic against other human wizards; it's possible Wardens are given somewhat of a free pass in regards to this Law in combat circumstances. The Law is very flexible, however, in regards to things that are not actually human. A wizard may kill, for example, a vampire, ghoul, or any being of the Nevernever without penalty.

2. Thou shalt not transform others. Thus demonstrating why, despite Harry's occasional threats, we will most likely never see him actually turn anyone into a frog. Even if done successfully (it is an extremely difficult spell), transformation of another's body against their will – changing a man into an animal, for example – creates an imbalance between body and mind that ultimately degrades the transformed subject's mind to an animal state as well. (Transformation of oneself through magic is not necessarily as destructive, but still risky and potentially hazardous)

3. Thou shalt not invade the mind of another. Forcible magical violation of someone's mind by extracting knowledge against their will is inherently destructive – Harry describes it as not black, but "dark, dark, dark gray". Mind magic is so dangerous that the Council has not even dared trying to explore how to build better defenses, which gives an advantage to black wizards less bound by scruples.

4. Thou shalt not enthrall another. Enthrallment is the term for dominating another human's mind and personality through magic by binding their will to your own; it is not the same as compelling beings of the Nevernever through arrangements or exchanges. So long as the wizard in question does not actually control the being through magic, the law is not broken. A popular alternative is trapping the creature in a magic circle until it accepts the terms of a bargain, though some Wardens have ignored this distinction in their zeal. As with mind-probing, magically controlling the mind of another person is an inherently destructive and evil act – it is almost impossible to control safely and precisely, and taints the user of the power as well as the subject even if done for the best of intentions. This taint often sends the user into a self-destructive downward spiral, where every act of magical mind control further twists the user and makes more such acts likelier; if the cycle progresses far enough, the user becomes functionally sociopathic, and impossible to rehabilitate.

5. Thou shalt not reach beyond the borders of life. This prohibits the research and practice of necromancy, described as the summoning, binding, and exploitation of the unwilling dead (the psychic talent of mediums for speaking to willing spirits is called ectomancy, and is not governed by the same Law). It would also theoretically prohibit any attempt to genuinely resurrect someone from the dead back to true life. In the universe of the novels, nobody is presented as knowing for certain what kind of afterlife, if any, exists; ghosts, even the most apparently intelligent and self-aware, are stated to be only psychic echoes of people created by violent death, not the actual souls of those people themselves. As the Laws are intended to protect humans against the abuse of magic, a loophole in this law (exploited by Harry in Dead Beat) allows the practice of necromancy on non-human dead.

6. Thou shalt not swim against the Currents of Time. This prohibits any attempt to change the past through temporal manipulation for fear of paradoxes. Even divination of the future is frowned upon in all but the vaguest, most general instances.

7. Thou shalt not seek beyond the Outer Gates. It is unknown just what the Outer Gates are, but the implication that they mark the furthest boundaries of the universe. Beings from beyond the Gates are known only as Outsiders, and are among the deadliest threats to humanity known – their sheer existence is antithetical to the universe (this may be a Lovecraft-inspired idea, as the Necronomicon has been mentioned in Blood Rites and Backup, and at least some of the beings living on the other side of the Gates are dubbed by Harry "the Old Ones"). They are also noted as being immune to most magic. One Senior Council member is known by the title of the Gatekeeper, conjectured to be permanently assigned to watch for attempts upon them due to the extreme threat.