The UK legal system is one that is based on precedence and case law. Over the course of hundreds of years, the courts have made decisions that impact how the law works today and how it will evolve in the future.

There are countless landmark decisions that have impacted the legal landscape in the UK and we have outlined just a few below:

The flu, smokeballs and contracts - Carlill v Carbolic Smoke Ball Co

Does a contract have to be a bilateral agreement to be legally binding? According to an 1892 decision from the Court of Appeal, apparently not.

In Carlill v Carbolic Smoke Ball Co, a decision often cited as a leading case in the common law of contract, the Court of Appeal held that an advertisement containing particular terms to get a reward is considered a binding unilateral offer that is accepted by anyone who completes its terms. In this case, the company created a flu remedy called the ‘carbolic smoke ball’. As part of its advertising campaign, the manufacturer stated that customers would be awarded £100 if they found it did not work. Mrs Louisa Elizabeth Carlill bought the product, used it for months, but still caught the flu. When the company refused the pay out, Mrs Carlill sued. The Court of Appeal found that the advertisement constituted a binding agreement as the essential elements of a contract – including offer and acceptance, consideration and an intention to create legal relations – were all present.

The Carlill case played a large role in developing the law of unilateral offers, and laid the foundation for the modern practice of outlawing misleading advertising.

Spanish fisherman and litigation funding - R (Factortame Ltd) v Secretary of State for Transport, Local Government and the Regions (No 2)

The Factortame case had wide reaching implications and resulted in quite a few important judgments. One such judgement impacted heavily on the development of third party litigation funding.

In this case, Factortame Limited, a Spanish fishing company claimed that the UK had broken European Union law with the requirement that ships must have a majority of British owners in order to be registered in the UK. Factortame won, successfully demonstrating that they had been illegally excluded from UK fishing waters and that they were also entitled to damages.

Due to the length and expense of the case, Grant Thornton, a firm of Accountants, made an agreement with Factortame, where the firm advised the claimant in return for 8% of the damages. One issue that arose was whether or not that contract was champertous, meaning it would be unenforceable. In addition to deciding in favour of Factortame, the judge in the case held that fee arrangement between the company and the accounting firm was not champertous. The judge found that funding litigation furthered the public policy objective of increasing access to justice, opening the door to the modern age of funded disputes.

The Paisley Snail and duty of care - Donoghue v Stevenson

The word negligence is a very common legal term nowadays. However, the modern concept of negligence can largely be traced back to 1932 when a House of Lords decision set out the principle whereby one person would owe a duty of care to another.

Mrs Donoghue went on holiday where, at a café in Paisley, she drank a bottle of ginger beer that happened to contain a dead snail. When she fell ill, she sued the manufacturer, Mr Stevenson. The case proceeded all the way from the Court of Session to the House of Lords, where the house held that the manufacturer was liable as he owed a duty of care to the customer. This duty of care was breached, because it was reasonable to foresee that a failure to ensure product safety could harm the consumer.

And thus, the neighbour principle – the idea one must take reasonable care to avoid acts or omissions that could reasonably be foreseen as likely to injure one's neighbour – was born.

Bias in the justice system – R v Sussex Justices, ex p McCarthy

We all know the old adage, "Not only must Justice be done; it must also be seen to be done.” But did you know the saying dates back to R v Sussex Justices, ex p McCarthy, a landmark English case on the impartiality and recusal of judges?

In 1923 a motorcyclist (McCarthy), was involved in a collision which led to prosecution before a magistrates’ court for dangerous driving. What McCarthy and his solicitor did not know was that the clerk for the justices was in fact a member of the firm of solicitors that was acting in a civil claim against McCarthy, linked to the traffic accident for which he was being prosecuted. McCarthy was convicted, but when he learned of this relationship he applied to have the decision overturned.

The appeal was heard by Lord Chief Justice Hewart, who found in favour of McCarthy because whether or not the justices were swayed by the clerk, there was an appearance of bias. The case established the principle that even the appearance of bias is adequate evidence to overturn a legal decision.