Abstract
The doctrine of illegality is one that has plagued the minds of legal scholars since Lord Mansfield CJ first uttered the words "ex dolo malo non oritur action" in 1775. With these words he ushered in over two centuries of case law, attempting to determine both the effect and extent of this maxim. The doctrine itself represents the broad public policy that no court will aid a person who founds their cause of action upon an immoral or illegal act. This sounds simple in theory, however application in practice has been arduous.
Many illegality cases involve illegal contracts. Despite New Zealand's colonial legal history, the approach taken to relief for illegal contracts has been very different in the United Kingdom and NZ, with the former being developed by the common law and the latter being dominated by statute. This dissertation will analyse these different approaches, their merits, and their pitfalls.