Dojo Darelir, the School of Xenograg the Sorcerer

Gift Exchange Revolves Around Three Obligations

Gift exchange is said to revolve around three obligations: the obligation to give, the obligation to receive, and the obligation to repay. If people do not give, no relationship can happen; the refusal to take a gift is the equivalent of refusing the relationship; and once something has been received a form of repayment deemed socially acceptable is absolutely necessary. Moreover, gifts to powerful forces must be an important sacrifice by those giving them; trivial things that will not be missed are not enough. It seems reasonable to conclude that things like metalwork or parts of human bodies deposited in the right places and with due care were gifts to the powers of the world, however these were conceived.

Magic: a History, pp. 223-24