Judicial precedent is the system by which decisions made by judges in earlier cases create rules that later courts must follow. When a court decides a legal issue, that decision becomes part of the law. Future courts dealing with similar facts are expected to apply the same legal reasoning.
Precedent exists to promote certainty, consistency, and fairness. If you advise a client, you need to be confident that the law will be applied the same way it was in previous similar cases. Without precedent, every case would be decided from scratch and outcomes would be unpredictable.
In practice, precedent works through law reporting. Judgments are published, and lawyers research previous decisions to find cases with similar facts and legal issues. You then present these authorities to the court, arguing that the same legal principles should apply. The judge must follow binding precedents and may choose to follow persuasive ones.
Understanding how precedent works is fundamental to almost every area of law you will study. When you see a case name in any SQE1 topic, ask yourself: what was the ratio, and is it still binding? This habit will serve you well across all subjects.
Stare decisis is Latin for "to stand by things decided." It is the underlying principle behind the doctrine of precedent. The idea is simple: once a court has decided a legal point, that decision should be respected and followed by courts in future cases involving the same legal issue.
Vertical stare decisis means that lower courts must follow decisions of higher courts in the same hierarchy. For example, the High Court must follow decisions of the Court of Appeal, and the Court of Appeal must follow decisions of the Supreme Court. This is the most important form of stare decisis and ensures uniformity throughout the court system.
Horizontal stare decisis means that a court is bound by its own previous decisions. The Court of Appeal is generally bound by its own earlier rulings, subject to limited exceptions. The Supreme Court, by contrast, can depart from its own previous decisions under the Practice Statement 1966, though it does so cautiously.
The court hierarchy is what gives precedent its force. Without a clear hierarchy, there would be no mechanism to determine which decisions are binding. The Supreme Court sits at the top, followed by the Court of Appeal, then the High Court, and below that the Crown Court, County Court, and magistrates' courts. Decisions flow downward: higher court rulings bind all courts below.
The ratio decidendi (or simply "ratio") is the legal reasoning that is essential to the court's decision. It is the principle of law on which the case was actually decided. Only the ratio is binding on future courts. Everything else in the judgment is obiter dicta.
Identifying the ratio is not always straightforward. Judgments can be long and contain multiple strands of reasoning. You need to look at the material facts the judge considered important and the legal principle applied to reach the decision. The ratio is the rule without which the case would have been decided differently.
Professor Goodhart developed a well-known method for finding the ratio. His approach focuses on the material facts as determined by the judge and the decision based on those facts. You identify which facts the judge treated as material, then state the principle of law that links those facts to the outcome. Facts the judge expressly or impliedly treated as immaterial are excluded.
Where a case is decided by a panel of judges (as in the Court of Appeal or Supreme Court), each judge may give a separate judgment with a different ratio. If the judges agree on the outcome but for different reasons, identifying a single binding ratio can be difficult. You may need to find the narrowest common ground between the judgments.
Obiter dicta (meaning "things said in passing") are statements in a judgment that are not essential to the decision. They might be hypothetical examples, comments about what the judge would have decided if the facts had been different, or discussions of legal principles not directly in issue. Obiter statements are persuasive but not binding on future courts.
Although obiter dicta are not binding, they can be highly influential. Obiter from senior courts, particularly the Supreme Court, carries significant weight. Lower courts will often follow obiter from higher courts out of respect for the seniority and expertise of those judges, even though they are not strictly required to do so.
In R v Howe [1987], the House of Lords stated in obiter that duress should not be a defence to attempted murder. This was later confirmed as law in R v Gotts [1992]. In Hedley Byrne v Heller [1964], the House of Lords established the principle of liability for negligent misstatement in obiter, because the actual claim failed on the facts due to a disclaimer. These examples show that obiter can shape the law just as powerfully as ratio.
In the SQE1 exam, you may be asked whether a statement from a case is ratio or obiter. Ask yourself: was this point essential to the actual decision, or was the judge discussing something hypothetical or tangential? If the case could have been decided the same way without that statement, it is obiter.
For a precedent to be binding, two conditions must be met. First, the previous decision must come from a court that is higher in the hierarchy than (or in some cases at the same level as) the current court. Second, the relevant part of the judgment must be the ratio decidendi, not obiter dicta. If both conditions are satisfied, the later court must follow the earlier decision.
The hierarchy determines which courts bind which. The Supreme Court binds all courts below it. The Court of Appeal binds the High Court and all lower courts. The High Court binds the County Court and Crown Court. Decisions of the Crown Court, County Court, and magistrates' courts do not create binding precedent, though they may have persuasive value.
| Court | Binds | Bound By |
|---|---|---|
| Supreme Court | All lower courts | Generally its own decisions (but can depart via Practice Statement) |
| Court of Appeal | High Court and below | Supreme Court; generally its own decisions (Young v Bristol Aeroplane exceptions) |
| High Court | County Court, Crown Court | Supreme Court, Court of Appeal; persuasive on other High Court judges |
| Crown Court / County Court | No binding precedent created | All higher courts |
| Magistrates' Court | No binding precedent created | All higher courts |
A persuasive precedent is one that a court is not obliged to follow but may choose to. Unlike binding precedent, a judge can consider a persuasive authority and decide not to adopt it, without breaching any legal rule. However, persuasive precedents can be very influential and are frequently relied upon in argument.
Not all persuasive precedents carry the same weight. Obiter from the Supreme Court is far more persuasive than a decision from a foreign court. The seniority of the court, the reputation of the judges, and how closely the facts align with the current case all affect how much weight a persuasive precedent receives.
Keep an eye on Privy Council decisions. Although only persuasive, the Privy Council often comprises the same judges who sit in the Supreme Court. In practice, lower courts sometimes treat Privy Council decisions as effectively binding, particularly where the Privy Council has expressly departed from an earlier House of Lords or Supreme Court decision.
Before 1966, the House of Lords (now the Supreme Court) was rigidly bound by its own previous decisions following London Tramways v LCC [1898]. This caused problems because errors in the law could not be corrected at the highest level. In 1966, Lord Gardiner LC issued the Practice Statement, declaring that the House of Lords would depart from its own previous decisions "when it appears right to do so."
The Practice Statement also warned that it would be used sparingly. The Lords recognised that certainty in the law is important and that people plan their affairs based on existing legal principles. Departing from precedent too readily would undermine confidence in the law. The Supreme Court continues to take this cautious approach today.
In R v R [1991], the House of Lords used the Practice Statement to abolish the marital rape exemption, holding that a husband could be guilty of raping his wife. In Herrington v British Railways Board [1972], the Lords departed from Addie v Dumbreck to modernise the duty of care owed to child trespassers. These cases show the Practice Statement being used to update the law where social attitudes had changed significantly.
The Supreme Court has declined to use the Practice Statement far more often than it has used it. In Jones v Secretary of State for Social Services [1972], the Lords refused to depart from a previous decision even though a majority considered it wrong, because certainty in social security law was more important. Always remember: the power exists, but it is exercised rarely and cautiously.
The Court of Appeal (Civil Division) is generally bound by its own previous decisions. This was established in Young v Bristol Aeroplane Co [1944]. The rationale is that if the Court of Appeal could freely depart from its own rulings, there would be less certainty and parties would constantly seek to reargue settled points.
A decision is per incuriam if the court failed to consider a relevant statute or binding precedent that would have led to a different result. This exception is applied narrowly. It is not enough that the previous court was simply wrong or that the law has moved on. There must be a clear oversight of a directly relevant authority.
The Court of Appeal (Criminal Division) has additional flexibility beyond the Young exceptions. Where following a previous decision would cause injustice to a defendant, the Criminal Division may depart from it. The liberty of the individual is at stake in criminal cases, so the court takes a slightly more relaxed approach to its own precedents. This was recognised in R v Taylor [1950].
The Young v Bristol Aeroplane exceptions come up frequently in SQE1 questions. A useful mnemonic is COP: Conflicting decisions, Overruled impliedly by a higher court, Per incuriam. If a question asks when the Court of Appeal can depart from its own previous decision, these three exceptions are your answer.
Overruling occurs when a higher court in a later case decides that a previous legal principle was wrong. The original case is not changed — it still stands on its own facts — but the legal rule it established is no longer good law. For example, the Supreme Court might overrule a Court of Appeal decision in a completely different case that raises the same legal issue.
Distinguishing is the most common way for a court to avoid following a binding precedent. The judge identifies a material difference in the facts between the earlier case and the current one, and concludes that the ratio of the earlier case does not apply. This allows the court to reach a different outcome without challenging the authority of the earlier decision.
Reversing happens when a higher court overturns the decision of a lower court in the same case on appeal. Unlike overruling (which involves a different case), reversing means that the actual decision in the original proceedings is changed. The appeal court concludes that the lower court applied the law incorrectly to the facts of that specific case.
Sometimes a court will express disapproval of a previous decision without formally overruling it. This might happen where the court is not in a position to overrule (for example, it is at the same level in the hierarchy) but considers the earlier decision to be wrong. Disapproved decisions carry less weight as persuasive authority but technically remain part of the law until formally overruled.
| Method | What Happens | Same Case or Different? | Effect on Earlier Decision |
|---|---|---|---|
| Overruling | Higher court declares earlier legal principle wrong | Different case | Ratio no longer good law |
| Distinguishing | Court finds material factual difference | Different case | Earlier decision stands but does not apply |
| Reversing | Appeal court changes the lower court's decision | Same case on appeal | Original decision overturned |
| Disapproving | Court criticises earlier decision but does not overrule | Different case | Earlier decision weakened but still technically law |
This is a common mistake in exams. Overruling involves a different, later case where the court declares a previous principle wrong. Reversing involves the same case going up on appeal. If a question says "the Court of Appeal reversed the High Court's decision," that means the same case was appealed. If it says "the Supreme Court overruled Smith v Jones," that means a new case has changed the law from Smith v Jones.
Precedent develops the law gradually through individual cases, while Parliament can make sweeping changes through statute. Each has its place. Precedent is better suited to fine-tuning legal principles and adapting them to new factual situations. Legislation is better suited to large-scale reform, particularly where social policy is at stake. In practice, the two work together.
If you are asked to evaluate the doctrine of precedent, don't just list advantages and disadvantages. Use specific cases to illustrate your points. For example, use R v R to show how precedent can adapt to social change, and use Jones v Secretary of State to show how rigidity can prevent necessary reform.
A common mistake is to treat precedent as completely rigid. The system has built-in mechanisms for change: the Practice Statement, the Young exceptions, distinguishing, and overruling. When discussing disadvantages, always acknowledge these safety valves. The examiner wants to see that you understand the system as a whole, not just one side of the debate.