Restatements of the Law are the most highly respected of all Secondary Sources, so much so that courts will cite them. But they are still technically persuasive authority. You also will not find one for every topic.
Some first-year law school courses have corresponding Restatements including:
Issued by the American Law Institute (a prestigious, invitation-only group of judges, law professors and lawyers), Restatements are an attempt to describe what the law is.
"Restatements are addressed to courts and others applying existing law. They aim at clear formulations of common law and its statutory elements or variations and reflect the law as it presently stands or might plausibly be stated by a court. Restatement black-letter formulations assume the stance of describing the law as it is."
Black Letter Law - a distillation of the common law rule (Hint: it will be in bold text)
A mistake is a belief that is not in accord with the facts. Restatement (Second) of Contracts § 151 (1981).
Comments - Explain what the black letter law means in more detail
Illustrations - Give hypothetical examples of how the black letter law should be applied in a given situation
Reporters Notes - Describe how a particular section was derived and often cites other types of secondary sources. They also list the actual legal opinions from which the Illustrations were derived.
Case Citations by Jurisdiction - Cases that cite this Restatement section
Also in Lexis+ and Westlaw Edge
The print Restatements are shelved in the bookcases in the middle of the Law Library Reading Room.
Restatements have both a Table of Contents and an Index
Restatements have pocket parts, and sometimes pamphlet supplements.
Uniform Laws are drafted to be the same across all jurisdictions, the most successful one is the Uniform Commercial Code.
They are drafted by the National Conference of Commissioners on Uniform State Laws (NCCUSL), also called the Uniform Law Commission.
Uniform Laws Annotated will tell you which states have adopted which sections of which Uniform Laws.
In Westlaw Edge and Uniform Law Commission website
Uniform Laws Annotated is available in Print at KF 879.A45 U5
Table of Contents and Index
Print version has pocket parts
Model Acts are written to show what the law should be, rather than what it is.
Anyone can draft a model act, but the most famous one is the Model Penal Code by the American Law Insititute--the same entity that drafts the Restatements.
Model Penal Code
The purpose of the Model Penal Code was to assist legislatures in making a major effort to appraise the content of the penal law by a contemporary reasoned judgment—the prohibitions it lays down, the excuses it admits, the sanctions it employs, and the range of the authority that it distributes and confers. Since its promulgation, the Code has played an important part in the widespread revision and codification of the substantive criminal law of the United States.