[AlexanderHowl]

In GURPS terms, sacrifice can also mean the sacrifice of character points (as represented by the Corruption rules from Horror). In the case of the previous rule, it would either represent the wasting of muscle tissue (representing the loss of ST) and the weakening of the cardiovascular system (representing the loss of HT). It is thematic of one of the most famous examples of sacrifice in European mythology, the crucifixion of Odin on Yggdrasil so he could gain the secrets of runic magic.

In order for a character to gain access to Magery through sacrifice, they would probably either have to suffer crucifixion (with each day allowing them to sacrifice one dot of Attribute for one level of Magery) or to suffer starvation (with each week allowing them to sacrifice one dot of Attribute for one level of Magery). In either case, the sacrifices are permanent, though they could be regain latter through spending CP. In the case of sacrificing DX or IQ for Ritual Adept, they would either have to suffer four days of crucifixion or four weeks of starvation to exchange one dot of DX and one dot of IQ for Ritual Adept, representing them suffering permanent neurological and psychological damage through their sacrifice.