First officially recognized in 1990, this is a new cause of action to stand alongside contract and tort in the law of obligations. This is a new and interesting area of contemporary legal development. The following topics will be covered during this course: the place of unjust enrichment in the law of obligations; remedies; subrogation; what counts as an enrichment; how the enrichment must be at the expense of the plaintiff; unjust factors such as mistake, duress, undue influence, exploitation of weakness, failure of consideration, legal compulsion, public authority ultra vires activity, ignorance, and necessity; defences; and controversies such as the nature of tracing, the availability of proprietary remedies, and the question of leapfrogging.