Rule statement and rule synthesis

The rule statement synthesizes key elements of the cases relevant to the issue in your case into a general statement of the rule. In order to produce an accurate and well-crafted rule statement, you must have a good understanding of the existing legal authority on which your rule statement is based.

Existing legal authority consists of constitutions, statutes, regulations, and decisional law, as well as past judicial decisions that have interpreted other sources of legal authority such as constitutions and statutes. The ostensible job of the court is to give effect to the intent of past lawmakers, e.g., legislators and regulators, in the context of a novel set of facts. Nonetheless, judges can sometimes make or change law themselves, acting on the same motives that legislators and regulators have: they want to address social problems, clarify, modify, or set aside lawmaking efforts of the past, or establish fair and efficient rules to help resolve novel disputes. However, all judicial decisions must rest upon and incorporate some preexisting legal rules and the rationale or policy behind those rules.

When the source of a rule is decisional law, keep in mind that a rule might not be stated explicitly or completely in a single case or group of cases; rather, it must be drawn out from the factual context in which the holdings in these cases have arisen. The writer of a rule statement engages in rule synthesis, pulling together common threads from multiple cases and reconciling discrepancies among them. A complete articulation of a synthesized rule accounts for all these threads and discrepancies. Accurate rule synthesis certainly requires the writer to consider the hierarchy of authorities, including the primary or secondary 3 nature of the authority, the mandatory or persuasive 4 nature of the authority, and the recency 5 of the authority.

It is considered good form in memo writing to make a clear statement about the synthesized rule before you provide the rule proof, i.e., before you discuss the cases from which you have distilled your rule statement. This format may seem counterintuitive to some. After all, you first have to read the cases and identify the guidelines and reasoning applied by those courts before you can distill from all those opinions the components of the synthesized rule. Nonetheless, from the reader's standpoint, your discussion is most understandable when you first state the main, organizing idea (extracted from the supporting cases) and then follow that statement with a discussion of the case law that supports and elaborates upon the main idea.

What does a good rule statement sound like? The answer depends in part on the purpose for which you are writing. When you write predictively, as in a law office memorandum that addresses an issue of common law, your rule statement should summarize the recurring elements (common threads) in judicial decisions involving that issue. It works best as a general statement of law that is phrased as a definition rather than as a question or a remark about what the court might consider or do.


3 Primary authority comprises constitutions, statutes, administrative regulations, and court decisions. Secondary authority refers to treatises, law review articles, and other published commentaries.

4 Mandatory authority is law (i.e., primary authority) that is binding on the court deciding the case. For example, decisions made by the New York Court of Appeals are binding on all lower courts in New York. Persuasive authority is law that is not binding on the court, although the court may, in its discretion, look to that law for guidance. For example, a Connecticut court is not bound by New York decisions; however, due the to the larger volume of New York cases, New York decisions may provide a richer exploration of the varying factual contexts or the policy analysis behind a particular legal rule than can be found in Connecticut case law. As a result, a Connecticut court may choose to look to New York case law for guidance. For the same reasons, a federal court in one circuit may choose to attach importance to the decisions of another circuit even though it is not bound by those decisions. Out of respect for the legal analysis of particular judges or particular decisions, a court may also attach importance to dicta in relevant cases.

5 A court is never bound by its own prior decisions. If two cases would be considered mandatory authority in a given jurisdiction, but the cases are inconsistent, the more recent case is binding. For cases that are merely persuasive authority, more recent opinions carry more persuasive value, all other things being equal.