by All forms of magic are governed by different rules, and each culture has different ways to harness and apply magic. However, all magic (with the only exception being captive genies) adheres to the following limitations:
Nothing Comes from Nothing. The act of conjuring an object, person, etc. relies on the principal that there is a set amount of matter in the universe, and that one cannot simply create new matter. It can be changed into different forms and moved around, but not created out of nothingness. When someone conjures an apple, they are either sacrificing something of equal value (a peach, for example) or they are plucking an apple from some unknown place (an apple disappearing from an orchard and appearing in their hands).
Magic Cannot Kill. That is, spells can be used to kill, but there is not spell that will instantly kill your opponent. You can use spells to attack them until they die, to sap their life energy, or to otherwise harm them, but you cannot utter a few magical words and kill them. The closest thing to a 'killing curse' is a highly complex ritual in which you must sacrifice your own life (or the life of another) to have the chance of dragging your victim to the Underland when the Spirit of Death comes to take you there. However, this only puts them in the Land of the Dead--it does not actually kill them. It also has a chance of backfiring, leaving you (the Caster) dead. Permanently.
Magic Can Only Brainwash. If you were to cast a love spell on someone then the emotion they experience would not be genuine love. It could manifest as anything from a sick obsession (resulting in a stalker) to a brain-dead slave (in the traditional sense of Brainwashing). Hatred, depression, glee, and any other emotions cannot be made genuine with magic. However, a clever Caster could use Illusionary magic to trick someone into developing genuine feelings--this is a loophole exploited by many.
Nothing Comes from Nothing. The act of conjuring an object, person, etc. relies on the principal that there is a set amount of matter in the universe, and that one cannot simply create new matter. It can be changed into different forms and moved around, but not created out of nothingness. When someone conjures an apple, they are either sacrificing something of equal value (a peach, for example) or they are plucking an apple from some unknown place (an apple disappearing from an orchard and appearing in their hands). Magic Cannot Kill. That is, spells can be used to kill, but there is not spell that will instantly kill your opponent. You can use spells to attack them until they die, to sap their life energy, or to otherwise harm them, but you cannot utter a few magical words and kill them. The closest thing to a 'killing curse' is a highly complex ritual in which you must sacrifice your own life (or the life of another) to have the chance of dragging your victim to the Underland when the Spirit of Death comes to take you there. However, this only puts them in the Land of the Dead--it does not actually kill them. It also has a chance of backfiring, leaving you (the Caster) dead. Permanently. Magic Can Only Brainwash. If you were to cast a love spell on someone then the emotion they experience would not be genuine love. It could manifest as anything from a sick obsession (resulting in a stalker) to a brain-dead slave (in the traditional sense of Brainwashing). Hatred, depression, glee, and any other emotions cannot be made genuine with magic. However, a clever Caster could use Illusionary magic to trick someone into developing genuine feelings--this is a loophole exploited by many.