In United States legal terminology, a dictum (plural dicta) is a statement of opinion or belief considered authoritative though not binding, because of the authority of the person making it.

There are multiple subtypes of dicta, although due to their overlapping nature, legal practitioners in the U.S. colloquially use dicta to refer to any statement by a court that extends beyond the issue before the court. Dicta in this sense are not binding under the principle of stare decisis

Stare decisis

Stare decisis is a legal principle by which judges are obliged to respect the precedents established by prior decisions...

, but tend to have a strong persuasive effect, either by being in an authoritative decision, stated by an authoritative judge, or both. These subtypes include:

• dictum proprium: A personal or individual dictum that is given by the judge who delivers an opinion but that is not necessarily concurred in by the whole court and is not essential to the disposition.
• gratis dictum: an assertion that a person makes without being obligated to do so, or also a court's discussion of points or questions not raised by the record or its suggestion of rules not applicable in the case at bar.
• judicial dictum: an opinion by a court on a question that is directly involved, briefed, and argued by counsel, and even passed on by the court, but that is not essential to the decision.
• obiter dictum
  Obiter dictum
  Obiter dictum is Latin for a statement "said in passing". An obiter dictum is a remark or observation made by a judge that, although included in the body of the court's opinion, does not form a necessary part of the court's decision...
  
  in Latin means "something said in passing" and is a comment made while delivering a judicial opinion, but it is unnecessary to the decision in the case and therefore not precedential (although it may be considered persuasive).
• simplex dictum: an unproved or dogmatic statement.

In English law

English law

English law is the legal system of England and Wales, and is the basis of common law legal systems used in most Commonwealth countries and the United States except Louisiana...

, a dictum is any statement made as part of a judgment of a court. Thus the term includes dicta merely in passing (referred to as obiter dicta) that are not a necessary part of the reason for the court's decision (referred to as the ratio decidendi

Ratio decidendi

Ratio decidendi is a Latin phrase meaning "the reason" or "the rationale for the decision." The ratio decidendi is "[t]he point in a case which determines the judgment" or "the principle which the case establishes."...

). English lawyers do not, as a rule, categorise dicta more finely than into those that are obiter and those that are not.