The addictive power of Vitae takes a special twist if a mortal or Kindred repeatedly tastes the blood of a single Kindred. In this case, an emotional dependence on that specific vampire adds to the general thirst for Vitae. The Kindred call this dependence the Vinculum, the blood bond or the blood oath. The vampire who created the bond is called the regnant; the bound Kindred or mortal is the thrall.
Some Kindred say that the Vinculum is the closest the Damned come to true love. If such is accurate, it is a terrible letdown, as the Vinculum is artificial and empty. It is not true love; it is simply a supernatural approximation. For many Kindred, it is a painful reminder of what they once had available to them as mortals, while the emotions they experience in the Requiem are little more than echoes of those lost feelings. The victim of a blood bond feels utterly devoted to his regnant and does nearly anything she asks. Dominate cannot overpower the thrall’s feelings for his regnant. Majesty imposes feelings for other Kindred, but it cannot negate the Vinculum’s hold.
The Kindred most often apply the Vinculum to mortals. A ghoul is, necessarily, blood bound after a period of days, weeks or even months. Kindred can also bond other Kindred. No one, however, can be thrall to more than one regnant. A Vinculum to one Kindred precludes the character becoming bound to another vampire, as long as the regnant still exists.