Magic in Orbis is concentrated around the "ley lines" which run from the core of the planet around the globe. When directly upon a ley line, all *good* spells such as healing and *neutral* spells such as building things cause no penalty to the spellcaster. So the major cities are not just near rivers, but are on top of ley lines as well. A piece of land with a ley line running through it is far more exspensive to buy. Ley lines are found with an enchanted piece of soft bendy wood that bends when over a ley line. *Bad* spells cast over a ley line can cause earthquakes or can make magicaly-made buidings fall apart or even vanish.Building spells only last for any length of time when upon a ley line.
The further away from a ley line, the more likely the caster is to feel sick when a spell is cast.Depending on the fitness and will of the caster, the preperations for the spell eg prayers,and the size of the spell, the consquences can range from no bad effect, all the way to death, as the spell takes energy from the caster.Some necromancers can take energy from other people, but such a thing is both illegal and will make the caster seriously unpopular.
White Magic, includes all the healing spells and all the spells that do great good to people. White wizards and witches are the doctors, lawyers, judges, city mayors, and most high ranking jobs are held by well-trained White mages, who are held in high esteem in society generally.
Grey Magic is all the spells which neither heal nor harm.Building spells are ranked "grey" as are spells to point one's way ect. Crystal ball magic is also grey.
Black Magic includes the necromantic arts as well as all spells that only cause harm. Black Mages/Witches are outlawed and persecuted unless there is a war and they agree to join the army.