Knowledge demands sacrifice.
"With the thirty-seven keys of Tzeentch, we open the way for our brothers! With the thousand whispers of Slaanesh, we call to them! With the twelve plagues of Nurgle, we fell their enemies! And with the mighty axe of Khorne, we cut open the world for them!"
— Word Bearer sorcerer, Warhammer 40,000: Dawn of War
"In magic, there is neither good nor evil. It is merely a science. The science of causing change to occur by means of one's will. The sinister reputation attached to it is entirely groundless and is based on superstition, rather than objective observation. The power of the will is something that people do not understand, attributing to it mysterious qualities that it does not posses. Being simply the power of 'mind over matter'. Or, in the greater number of cases, the power of mind over mind. As your mind now is succumbing to mine..."
— Mocata, The Devil Rides Out
Pain erupted in my left palm. The power was cold-and not mountain-breeze cold, either. It was slimy and nauseating, like something that had come slinking out from the depths of some enormous subterranean sea. In that instant of contact, my head exploded with terror. This power, this black magic, was wrong. Fundamentally, nightmarishly, intensely wrong.
— Harry Dresden, The Dresden Files
Black magick isn't a matter of tools or rituals — many primal styles use rites that make "civilized" people blanch. Black magick comes from motivation, from spite, hatred, rage, lust. It twists, burns, compels, commands. It's a mystickal shotgun aimed at the heads of your enemies, a knife in the heart of everyone you despise. More often than not, a maleficent magician strikes bargains with Infernal entities — the devils and demons her parents warned her about — and appeasing them with sacrifices, blasphemies, vandalism and terrorism. The ultimate power, however, comes from the hatred within the mage, not from demonic pacts. Although some lesser powers flow from demonic hands, the true black magician holds the keys to her own damnation... gladly.
—Mage: The Ascension — The Orphan's Survival Guide
Trug spoke an incantation. A bolt of black force leaped from his fingers and struck Junior in the chest. The World's Mightiest Boy gasped. Freezing coldness paralyzed his lungs and spread through his body.
I have met people who claimed to be Satanists. Who claimed to be involved with Black Magic. Who claimed that they not only knew a lot about it. But as I said, I certainly haven't been involved, and I warn all of you: never, never, never. You will not only lose your mind, you'll lose your soul.
BLACK ARTS. All MAGICS of an unpleasant and antisocial nature. They are normally to do with killing and enslaving things and normally require a SACRIFICE as a preliminary, or at least a lot of blood. The mark of the Black Arts is that the blood is not willingly donated. Practitioners will either trick Tourists and others into donations or seize them and cut them, often with a knife that looks rather unpleasant. There will then be lots of mumbling and GESTURES around a PENTAGRAM, during which there will be a sense of wrongness or a feeling of extreme cold; in extreme cases, terror blooms. This usually heralds the arrival of a DEMON who is about to get out of control. Practitioners can be of all grades of expertise, from the feeble person who merely wishes for a little power (and gets steadily more corrupted) to the high ADEPT who regularly summons Demons and enslaves ARMIES. Some of them will be adherents of the DARK LORD. Some of them will have set up on their own. Tourists may expect to meet someone who is into the Black Arts at fairly infrequent but regular intervals along the way.
