A blood bond which is formed after drinking a vampire’s blood. It is an intense state of artificial love which becomes stronger with each drink. After three drinks it becomes permanent. While the hold of a vinculum is very tight it isn’t perfect. It is possible to rebel under a vinculum especially if it was forced upon its subject. Under a full vinculum the subject is incapable of direct rebellion, but can undermine and sabotage his Regnant still. This is especially effective because it is easy for the regnant to take his thrall’s obedience for granted.