Nightwatch magic: Spellcasters draw their power from either Light or Darkness, feeding on people's positive or negative emotions (respectively). This power is then reshaped into magic. A magician can channel power directly into effects, while a witch or wizard must use things such as amulets, potions, and the like. However, witches and wizards have a much more subtle and wider range of effects available to them, while magicians are usually limited to affecting their immediate environment.
Spellcasters are divided into seven levels of power, with level one being the highest. Beyond this are magicians of "unclassified" power, who might as well be demigods. A magician of a lower power level has almost no change of affecting a higher level magician, or of resisting the higher level spells. Likewise, all magicians are able to enter the Twilight, the world of magic, which has its own five levels. The more powerful the magician, the further they can travel. For each successive level of the Twilight, more power is required to enter, senses are more obscured, and time moves at a faster pace. Thus, magicians on lower levels have a logistical advantage over those who cannot follow them.
Any curse, from a brief ill thought to the worst profanity, has real effect in the Twilight. The worst curse of a human might just cause the recipient to stub a toe or break a nail. Curses from spellcasters, however, manifest as magical effects, and hover over the victim for days. Powerful ones can even harm those around the victim. Unfortunately, blessings or showers of affection do not work the same way.
