" One—that each coven must have its leader and only he might order the working of the Dark Trick upon a mortal, seeing that the methods and the rituals were properly observed. Two—that the Dark Gifts must never be given to the crippled, the maimed, or to children, or to those who cannot, even with the Dark Powers, survive on their own. Be it further understood that all mortals who would receive the Dark Gifts should be beautiful in person so that the insult to God might be greater when the Dark Trick is done. Three—that never should an old vampire work this magic lest the blood of the fledgling be too strong. For all our gifts increase naturally with age, and the old ones have too much strength to pass on. Injury, burning—these catastrophes, if they do not destroy the Child of Satan will only increase his powers when he is healed. Yet Satan guards the flock from the power of old ones, for almost all, without exception, go mad. In this particular, let Armand observe that there was no vampire then living who was more than three hundred years old. No one alive then could remember the first Roman coven. The devil frequently calls his vampires home. But let Armand understand here also that the effect of the Dark Trick is unpredictable, even when passed on by the very young vampire and with all due care. For reasons no one knows, some mortals when Born to Darkness become as powerful as Titans, others may be no more than corpses that move. That is why mortals must be chosen with skill. Those with great passion and indomitable will should be avoided as well as those who have none. Four—that no vampire may ever destroy another vampire, except that the coven master has the power of life and death over all of his flock. And it is, further, his obligation to lead the old ones and the mad ones into the fire when they can longer serve Satan as they should. It is his obligation to destroy all vampires who are not properly made. It is his obligation to destroy those who are so badly wounded that they cannot survive on their own. And it is his obligation finally to seek the destruction of all outcasts and all who have broken these laws. Five—that no vampire shall ever reveal his true nature to a mortal and allow that mortal to live. No vampire must ever reveal the history of the vampires to a mortal and let the mortal live. No vampire must commit to writing the history of the vampires or any true knowledge of vampires lest such a history be found by mortals and believed. And a vampire’s name must never be known to mortals, save from his tombstone, and never must any vampire reveal to mortals the location of his or any other vampire’s lair. These then were the great commandments, which all vampires must obey. And this was the condition of existence among all the Undead. "
― Anne Rice , The Vampire Lestat (The Vampire Chronicles, #2)