Skip main navigation

What is ‘the rule of law’?

This article introduces the nature of law as a system of rules and the key sources of law within our legal system: legislation and case law.

Watch this video to hear us introduce you to the nature of law as a system of rules, and what distinguishes law from other sets of rules that we encounter in our daily lives.

Now that you’ve watched the video, let’s explore law a bit more.

Where does ‘the rule of law’ come from?

Within the legal system of the UK, there are two main sources or forms of law: legislation and case law.


An institution with law-making powers is known as a legislature. Legislation is the term for sets of written rules that have been approved (or ‘enacted’) by a legislature. This includes rules made under powers delegated by a legislature.

There is an important distinction between ‘primary’ legislation and ‘secondary’ or ‘delegated’ legislation.

Primary legislation

In the UK, most primary legislation consists of Acts of Parliament.

The legislative process begins with draft legislation (a ‘Bill’) proposed by the UK government. It is then passed to the UK’s legislature – the UK Parliament – where it goes through a process of parliamentary scrutiny and approval. It only has the force of law once the process is completed and the legislation has been enacted by Parliament.

Devolution in the UK means that the regional legislative bodies – the Scottish Parliament, Welsh Parliament and the Northern Ireland Assembly – have the power to make laws for their regions.

Acts of Parliament are often known as ‘statutes’.

Secondary legislation

In absolute terms, only a very small portion of the new legislation introduced each year is primary legislation. Far more legislation – several thousands of items each year – is secondary legislation, often known as statutory instruments.

For example, every year between 2010 and 2019, there were between 23 and 41 UK Public General Acts (the main form of primary legislation), but between 1,243 and 3,481 UK statutory instruments (the main form of secondary legislation).

That is over fifty times as many pieces of secondary legislation. So, what is the difference?

Secondary legislation is made by a person or body using powers conferred on (or ‘delegated to’) that person or body by primary legislation.

The most common example is when the power to make secondary legislation is conferred by an Act of Parliament on a relevant government minister.

Case law

Legislation is not the only source of law.

A considerable amount of our law derives instead from ‘case law’: rules and principles that are, in an important sense, judge-made.

To understand this, we need to know a little more about the court system and the nature of judicial decision-making. Check out the full online course, from the University of Cambridge, below.

This article is from the free online

Exploring Law: Studying Law at University

Created by
FutureLearn - Learning For Life

Reach your personal and professional goals

Unlock access to hundreds of expert online courses and degrees from top universities and educators to gain accredited qualifications and professional CV-building certificates.

Join over 18 million learners to launch, switch or build upon your career, all at your own pace, across a wide range of topic areas.

Start Learning now