Harm none (the Wiccan Rede)

Wiccans widely affirm the Wiccan Rede, most often summarized in the couplet An it harm none, do what ye will, a counsel that one is free to act as one wills provided the action harms no one, oneself included. Historians of modern Wicca, Ronald Hutton prominently in his study The Triumph of the Moon, trace the Rede's wording and popularization to the movement's formative decades in England, and note its clear echo of, and deliberate modification to, the Thelemic maxim Do what thou wilt shall be the whole of the Law, associated with Aleister Crowley, whose ceremonial magic was one of several currents Gerald Gardner drew on in shaping early Wicca; the addition of an it harm none narrows Crowley's more expansive formula into an explicitly ethical constraint that the earlier phrase, on its own, did not contain.

The Rede is a guideline rather than a commandment, placing responsibility on the practitioner to weigh the consequences of their own actions rather than consulting a fixed external code, reflecting Wicca's broader emphasis on personal ethical judgment, experience, and conscience over received rules handed down by scripture or clergy. Scholars of new religious movements have noted that this shift, placing final ethical authority in the individual practitioner rather than in a text or an ordained hierarchy, is itself one of the more distinctively modern features of Wicca's overall religious structure.

The Rede is one of the best-known principles of modern Wicca and of much of the broader contemporary Pagan movement, held across many of its traditions, though not universally in identical wording or with identical weight; some lineages treat it as close to a defining law of the Craft, while others regard it as one useful maxim among several rather than a binding rule. Because harm none is difficult to apply as an absolute standard, given that almost any action carries some risk of harm to someone, Wiccans generally understand the Rede as a call to mindfulness and to minimizing harm rather than a rule admitting no exceptions or trade-offs, and practitioners have long debated how it should apply to genuinely hard cases, self-defense, difficult ethical decisions in ordinary life, or the use of magic to influence another person's will without consent.

It works together with the Threefold Law, the belief that one's actions return upon oneself magnified, to give Wiccan ethics a shape grounded in personal accountability and the deliberate weighing of consequences rather than in commands received from an external deity or a fixed legal code, a structure that sets Wiccan ethical reasoning apart from traditions built primarily around revealed commandments.