Legal Definitions - common-law rule

A common-law rule is a legal principle or standard that has been developed and established by judges through their decisions in individual court cases, rather than being created by a legislative body (like a parliament or congress). These rules are built upon legal precedents, meaning that past judicial rulings serve as authoritative guides for future similar cases. Common-law rules form a foundational part of legal systems inherited from English legal tradition and can be contrasted with statutory law (laws written and passed by legislatures) or regulatory law (rules created by government agencies).

Here are some examples to illustrate the concept of a common-law rule:

• The "Duty of Care" in Negligence Cases

  Scenario: A pedestrian slips and falls on a wet floor in a grocery store that had just been mopped, but no "wet floor" sign was displayed. The pedestrian sues the store for negligence.

  Explanation: The legal concept that individuals and businesses owe a "duty of care" to others to avoid causing foreseeable harm is largely a common-law rule. There isn't a single statute that exhaustively defines what constitutes a reasonable duty of care in every possible situation. Instead, judges, through centuries of court decisions, have developed and refined this principle, determining when a duty exists, what standard of care applies (e.g., acting as a "reasonably prudent person"), and when that duty has been breached. Courts apply and adapt this judge-made principle based on the specific facts of each case.

• The "Attractive Nuisance" Doctrine for Child Trespassers

  Scenario: A homeowner leaves an old, broken-down car in their unfenced backyard. A curious child from a neighboring property, attracted by the car, wanders onto the property to play in it and is injured by sharp metal edges.

  Explanation: Historically, landowners generally owed very little duty to trespassers. However, judges developed the "attractive nuisance" doctrine as a common-law exception to this rule. This doctrine makes landowners liable for injuries to trespassing children if the landowner maintains a hazardous condition on their property that is likely to attract children. This rule was not created by a legislature but evolved through numerous court decisions that recognized the unique vulnerability and curiosity of children, creating a specific duty where none existed before for adult trespassers.

• Basic Principles of Contract Formation

  Scenario: Two business partners have a verbal agreement to share profits from a new venture. When the venture becomes successful, one partner refuses to share the profits, claiming there was no formal written contract.

  Explanation: Many fundamental principles governing how contracts are formed, such as the requirements for an "offer," "acceptance," and "consideration" (something of value exchanged), originated and were refined through common-law judicial decisions over centuries. While some aspects of contract law are now codified in statutes (like the Uniform Commercial Code for contracts involving the sale of goods), the core framework for many types of contracts, especially service agreements or general business arrangements, remains rooted in these judge-made common-law rules, which courts continue to interpret and apply in disputes.