Stare decisis, short for the Latin maxim stare decisis et non quieta movere ("to stand by things decided and not disturb settled matters"), is a foundational principle of common law systems. It obliges courts to follow the reasoning of earlier decisions when adjudicating cases that raise substantially similar legal questions, promoting consistency, predictability, and the appearance of impartiality in judicial decision-making.
The doctrine operates along two axes:
- Vertical stare decisis binds lower courts to follow the rulings of higher courts within the same jurisdiction. A U.S. federal district court, for example, must apply the holdings of the Supreme Court and of its governing circuit court of appeals.
- Horizontal stare decisis refers to a court's practice of following its own prior decisions. This form is generally treated as a strong default rather than an absolute rule, particularly at apex courts.
Stare decisis is most strongly associated with common law jurisdictions such as the United Kingdom, the United States, Canada, Australia, and India. Civil law systems (e.g., France, Germany) historically place less formal weight on individual precedents, though in practice consistent case law (jurisprudence constante) plays a significant role. International tribunals such as the International Court of Justice are not formally bound by their own prior rulings — Article 59 of the ICJ Statute limits the binding force of judgments to the parties and the particular case — but they routinely cite past decisions for persuasive authority.
Courts may depart from precedent when an earlier ruling is shown to be unworkable, badly reasoned, or inconsistent with later legal developments. The U.S. Supreme Court overturned Plessy v. Ferguson (1896) in Brown v. Board of Education (1954), and overruled Roe v. Wade (1973) and Planned Parenthood v. Casey (1992) in Dobbs v. Jackson Women's Health Organization (2022). The UK House of Lords formally announced its willingness to depart from its own precedents in the 1966 Practice Statement.
For MUN delegates drafting legal committee resolutions or ICJ simulations, recognizing how precedent functions — and when it can be set aside — is essential to framing credible legal arguments.
Example
In *Dobbs v. Jackson Women's Health Organization* (2022), the U.S. Supreme Court departed from stare decisis by overruling *Roe v. Wade* (1973) and *Planned Parenthood v. Casey* (1992).
Frequently asked questions
No. Vertical stare decisis is generally binding on lower courts, but apex courts such as the U.S. Supreme Court and the UK Supreme Court can and do overrule their own past decisions when they consider it justified.
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