Rule of necessity – this is a very rare legal rule, entitling a judge who has a conflict of interests (i.e. a personal benefit) in the outcome of a lawsuit, to hear it anyway. In the modern court trials it finds application very limitedly and only in extraordinary cases, because judges should not decide on a case in which they personally participate or have interest in the outcome of it – i.e. the legal principle “nemo judex in sua causa” (nobody should decide on a case where they pursue personal benefit).