precedent

 (pre-səd-nt) (n)

:a judicial decision that should be followed by a judge when deciding a later similar case

see also stare decisis 

compare dictum 

To serve as precedent for a pending case, a prior decision must have a similar question of law and factual situation. If the precedent is from the same or a superior jurisdiction (as the state's supreme court), it is binding upon the court and must be followed; if the precedent is from another jurisdiction (as another state's supreme court), it is considered only persuasive. Precedents may be overruled esp. by the same court that originally rendered the decision.