Dark Sun: The Scorched World of Athas
Arcane magic is one of the many power sources used by heroes and villains for their extraordinary abilities. Arcane magic is dangerous and uncommon on the world of Athas. Without taking special care an arcane spellcaster can defile the immediate surroundings by cast a spell. Arcane magic is gathered from the fundamental energy of living organisms (normally plants, but sometimes animals and even people) before being released as the spells. It is a choice when the spell is cast as to how the energy is collected. The common people do not realize, or care, about the distinction between preserving and defiling, hating all users of arcane magic equally.
The easiest and most expedient path to arcane power is defiling which transforms small plants and vital nutrients in the soil into ash. Larger plants blacken and become brittle, often dying days later. Extremely powerful arcane spellcasters can pull energy from animals causing the death of small animals and injury to larger animals (including humanoids).
Necromancers derive the power for their spells from the Gray and have no effect on surrounding plant life. The outwards signs when casting their spells are still recognizable as arcane in nature and thus they must off use deception to keeps their powers undetected. Necromancers have a stigma associated with their power and are generally the most reviled arcane casters.
Preserving is the process of using arcane magic that maintains the balance of energy, drawing just enough to use the magic, but not so much that plant and animal life is destroyed. Because there is no outward sign of magic, preservers often attempt to disguise their abilities as manifestations of the Way.
In the Lands Within the Wind there exists another form of magic, virtually unknown of on Athas, an ancient practice of magic that is part ritual, part mystery and part religion. The link between a witch and her magic is through a familiar (an animal companion). The magic of witches is usually subtle in its effect, entrancing and binding creatures to their will. Each coven has their own beliefs on the best use of magic. Members of he Full Moon Coven, for example, believe in the sanctity of life and the capacity of pure beauty to enchant the eye and use their magic to beguile, charm and inspire.