Prior cases whose principles are used by judges to decide current cases are called

Precedents

Explanation:

A precedent is a decision/principle that is the basis of or the cause for future decisions. The principles used in prior cases are applied by courts whenever the case to be heard has similar issues or facts. This is in accordance with the doctrine of "stare decisis" (i. e. to stand by things decided), through which courts apply the precedents of prior cases if the case at issue is similar. This doctrine ensures consistency in the legal system.

There are two types of precedents: binding precedents and persuasive precedents.

A binding precedent is a precedent a court must conform to upon the adjudication of the case. A lower court is to abide by the decisions of a higher court, even if the lower court does not agree with those decisions.

A persuasive precedent is that a court may observe but the court is not required to do so. For instance, those decisions made by courts having the same jurisdiction.