 Finally, allocation must take account of incentives in two distinct ways. It must consider how the scheme would be operated. The ideal application of first-best principles would require considerable flexibility and discretion. Fixed rules or algorithms inevitably fail to capture all the relevant information. And yet flexibility and discretion are open to gaming by doctors and patients, for instance in exaggerating the urgency of transplanting a patient. Thus incentive effects may make an ideal method sub-ideal in practice.