 The scarcity of organs creates an allocation problem. A great deal has been written in philosophy on the principles of the allocation of scarce resources, although not much on the allocation of organs specifically (see the entries on  distributive justice;  equality;  justice and access to health care).  Unsurprisingly, many of the principles cited in official transplantation allocation documents are familiar (see  Other Internet Resources:  TSANZ 2014; NHSBT 2013). These principles include allocating to those who would benefit the most (a proxy for utility), to those who are the sickest (a proxy for helping the worst off), to those whose medical condition will deteriorate the soonest (urgency), and to those who have been waiting the longest (often linked to equity). Official documents also stress principles of non-discrimination, which are taken to exclude allocating according to judgments of social worth, as well as race, sex, religion etc. In practice, the principles conflict; the person waiting the longest may not be the one who would gain the most from a transplant, for example. So official allocation protocols also have to say how the conflict between principles should be resolved. (For a philosophical discussion of the principles and their application to organ allocation see Kamm 1993.)