The law applicable to the facts of a dispute may be contained in an Act of Parliament, and knowing the law then involves interpreting a legislative text. Unlike case law, where judges construct their own texts out of precedents (rationes decidendi), with statute law the texts are presented to them.

Legislation may be described as law made deliberately in a set form by an authority, which the courts have accepted as competent to exercise that function. From sparse and scanty beginnings, its use steadily increased until now the output of statutes has assumed formidable proportions. Although the volume and the nature of certain kinds of legislation may be subjected to criticism, there is universal agreement that deliberate law making of this kind is indispensable to the regulation of the modern state. The part played by the judges in the struggle between the prerogative and Parliament enabled them to preserve in their hands a considerable measure of power, one aspect of which is that what becomes ‘law’ is their interpretation of statute through the operation of stare decisis. As Lord Devlin has put it: