Australia's High Court has ruled that a written contract will determine whether a worker is an employee or a contractor. We require all relevant qualifications to be successfully completed in the first sitting, e.g.Implied terms are provisions that are not explicitly stated in a contract but are nevertheless considered as integral components of the agreement. A v Hayden (1984) 156 CLR 532. Illegality - contracts prejudicial to administration of justice. The basic principle of Australian contract law is freedom of contract, under which parties are at liberty to strike whatever bargain they choose. Contract in Commercial Law is a collection of essays based on the papers presented at the Contracts in Commercial Law Conference 2015.