Case law, common law, unwritten law, and judge-made law all refer to the same judicial principle – law made by judges in reported appellate decisions. This form of judicial precedent is fundamental to the American legal system.
Case law: Law based on judicial precedent rather than on legislative statutes or administrative regulations. Once the judge has made the decision, that decision itself becomes a legal precedent.
Common Law: Judicial precedent as set forth in reported appellate court.
Statutes: Law made by the legislature in the form of statutes.
The doctrine underlying the common law is that there must be respect for precedent, or prior decisions of the courts. This doctrine is Stare Decisis, and the application of this doctrine requires that attorneys and legal researchers must have access to the prior decisions of the judiciary.
“Decision” and “opinion”
Decision and opinion are words that are often used interchangeably. However, a court or agency’s written opinion is an explanation of why the court or agency took the action it did, while the decision is the actual action that the court or agency took (judgment for a party, affirmed, reversed, case dismissed, etc.).
Court Reports are hardbound publications of the opinions of appellate courts. These reports are largely chronological by the dates of the decisions, although there can be minor exceptions. The reports are issued serially.
Some trial courts issue written opinions on issues of law. For example, the federal district courts will issue published written opinions in the Federal Supplement (now in its third series).
Some state trial courts also issue written published opinions. These published trial court opinions are important to the legal researcher, particularly when a case now before the court presents similar legal issues as a prior case decided by the same court.
Slip Opinions and Advance Sheets
A slip opinion is the publication of an opinion in print or online soon after the opinion has been issued by the court. An advance sheet is a publication of a collection of recent court opinions. Advance sheets are also referred to as advance opinions or advance reports.
The difference between slip opinions and advance sheets is that a slip opinion is a single case, while an advance sheet publishes several (and usually many) slip opinions (and frequently from several different courts). Opinions published in advance sheets may be revised or withdrawn by the court that issued the opinion before the opinion is published in the permanent hardbound report.
Advance sheets generally paginate the collected slip opinions contained in the advance sheet, and this case pagination is usually retained in the bound court reports. But note, if you cite a case with the pagination of an advance sheet, you may be in peril if the issuing court has subsequently withdrawn the opinion from publication. Always check to assure that advance sheet citation has been retained in the reporter.