==Blood Bond Levels and Effects==
The drinker begins to experience intermittent but strong feelings about the vampire. She may dream of him, or find herself "coincidentally" frequenting places where he might show up. There is no mechanical effect at this stage, but it should be roleplayed. All childer have this level of bond toward their sires, for the Embrace itself forces one drink upon the childer; they may love their "parents," hate them, or both, but are rarely indifferent toward them.
The drinker's feelings grow strong enough to influence her behavior. Though she is by no means enslaved to the vampire, he is definitely an important figure in her life. She may act as she pleases, but might have to make a Willpower roll to take actions directly harmful to the vampire. The vampire's influence is such that he can persuade or command her with little effort (Social rolls against the thrall are at -1 difficulty).
Full-scale blood bond. At this level, the drinker is more or less completely bound to the vampire. He is the most important person in her life; lovers, relatives and even children become tertiary to her all-consuming passion.
At this level, a regnant may use the Dominate Discipline on a thrall, even without the benefit of eye contact. Merely hearing the regnant's voice is enough. Additionally, should the thrall try to resist the Dominate for some reason, the difficulty of such resistance is increased by two. Naturally, a higher-generation vampire still cannot use Dominate on a lower-generation thrall.
The blood bond is true love, albeit a twisted and perverse version of it. Ultimately, we can't reduce the vagaries of love down to a simple "yes/no" system. Some thralls (particularly people with Conformist or other dependent Natures or with Willpower 5 or less) will commit any act, including suicide or murder, for their beloved; other characters have certain core principles that they will not violate.
A full blood bond, once formed, is nearly inviolate. Once bound, a thrall is under the sway of her regnant and her regnant only. She cannot be bound again by another vampire unless the first blood bond wears away "naturally." A vampire can experience lesser (one- and two-drink) bonds toward several individuals; indeed, many Kindred enjoy such bonds, as they create artificial passion in their dead hearts. Upon the formation of a full blood bond, though, all lesser sensations are wiped away.
Vampire lovers occasionally enter into mutual blood bonds with each other; this is the closest thing the undead can feel to true love. Even this sensation can turn to disgust or hate over the centuries, though, and in any event few Kindred are trusting enough to initiate it. A blood bond is a mighty force, but it is at its most potent when perpetually reinforced with further drinks.
Feeding a thrall often reinforces the bond, while depriving a thrall of vitae may cause the bond to grow tepid over time. As well, like any other relationship, treatment and courtesy play a part in the dynamics of the bond. A thrall who is treated well and fed often will likely fall even more deeply in love, while a thrall who is degraded and humiliated may find resentment and anger eating away at the bond.