Before you begin to research a legal question or file a lawsuit, it's a good idea to understand the basics about the U.S. Courts and legal system, including the following:

How do I find out what "the law" is on a particular topic?

What are some of the legal concepts I should be aware of before I start my research?

What is the difference between state and federal courts, and how do I know where to file a lawsuit?

There are two primary sources for determining what the law is on a particular issue: statutes and case law. Both can be equally important in ascertaining what the law is and how a judge or court will rule on a given issue in a legal case.

The Role of Statutes
Statutes are laws that begin as bills, which are written, voted on, and either passed or rejected by legislative bodies, such as the U.S. Congress and state legislatures. Statutes are often organized by subject into "Codes,""Acts," or "Titles." For example, in California, the majority of the state's statutes dealing with Family Law issues are grouped together in the California Family Code.

• Note: A "Code" may also refer to the main body of statutes for an entire jurisdiction, such as the U.S. Code, which is the primary body of federal statutes, grouped by subject into Titles, such as Title 11, which contains hundreds of bankruptcy statutes, or Title 42, which is comprised of civil rights laws. A "citation" or "cite" is the official, numeric identification of a law that describes where it is published. For example, the federal citation 42 U.S.C. 1983 identifies section 1983 of Title 42 of the U.S. Code. Citations often include the symbol "¤," which means "section" (e.g., 42 U.S.C. ¤ 1983).

Often, statutes authorize the filing of lawsuits; in such a case, the statute is said to create or give rise to the cause of action. For example, an individual who wants to sue his or her employer for discrimination may be entitled to do so under the authority of 42 U.S.C. section 1983. In other situations, such as in criminal law, an individual may be charged by an executive agency, such as the U.S. Attorney's Office, with a violation of a statute. When disputes arise over the meaning of statutes, state and federal courts are called upon to determine what the law is and what specific statutes are intended to mean.   (This is one of the fundamental examples of how our system of "checks and balances" functions, in that courts are given Constitutional authority to independently review laws passed by the legislative branch of government). In interpreting a statute, however, a court will defer to what the legislature must have intended in passing the law and, to determine "legislative intent," courts look to a number of sources.

How Do Courts Interpret Statutes?
First, in interpreting a statute, a court will always begin by determining whether the statute as written is ambiguous. If the statute is clear, the court will rely on the "plain language" of the statute, and apply its terms according to their commonly understood meanings to the facts of the case. If a statute is ambiguous, however, the court will look to sources outside the language of the statute itself. Initially, the court will examine the relevant "statutory scheme," which is the body of statutes within the relevant jurisdiction that relate to or affect the statute at issue. Sometimes, the intended meaning of an unclear statute will be made clear by reading other, related statutes.

Another source the court may look to is the "legislative history" of a statute. The legisltive history provides background information as to how and why a statute was created, which is documented in a collection of materials such as committee reports, floor debates, and revisions to the statute. The legislative histories of recently enacted federal statutes can be found at the Library of Congress' THOMAS web site . The legislative histories of state statutes are not as easily accessible, but are usually kept by state government libraries. (Go to FindLaw's State Resources pages for help in locating these individual offices).

Statutes & Case Law
Courts also look to "case law" (see below) for guidance in interpreting statutes, and they may consider as persuasive the decisions of other courts that have interpreted similar or related statutes.

• Research Tip: A good starting place for legal research is in the "annotations" to a statute. Annotations appear in various legal publications and may consist of explanatory information about a statute, e.g., the dates the statute became effective, was revised or repealed, and references to case law interpreting the statute.

What are Regulations?
Federal and state agencies, such as the IRS or the Department of Education, are given authority by the legislature to issue regulations in the subject area each agency controls. These regulations are rules addressing how the statutes the legislature has passed will be implemented, or carried out. In interpreting statutes, courts will often adopt interpretations given or suggested by the administering agencies. Such interpretations may be found in the regulations themselves, or in the published decisions of the administrative agencies. The regulations issued by federal government agencies are compiled by subject into Titles, and are searchable on FindLaw's Code of Federal Regulations page. Regulations issued by state administrative agencies are typically compiled in each state's administrative code (for example, the "Illinois Administrative Code"); thus, to research individual state regulations, you would look to FindLaw's State Resources to find a state administrative code or agency.

• Note: Sometimes, regulations contain additional rules or requirements not contained in the related statutes, so it is important to read any relevant regulations when researching a legal issue. Additionally, if you are involved in a matter over which an administrative agency has jurisdiction, you will likely have to go through that agency's administrative process before you may file a lawsuit in court. This is known as "exhausting" your administrative remedies.

Case Law
Once a court determines what the law is on a given issue (for example, when it determines what a given statute means), it applies the law to the facts of the case before it, and issues its decision. Case law is law made by courts in published decisions called opinions. Only published opinions may be considered "precedential," meaning they have become "law." When a case is precedential, other courts within that jurisdiction are bound to apply the rule and reasoning announced in the opinion, to ensure certainty and consistency in the administration of the law. However, courts may depart from precedent for compelling policy reasons, or where the facts of one case are significantly distinguishable from the other.

In most cases, courts are called upon to interpret and apply statutes, however, judicial opinions also continue to define and develop what is known as the "common law." Common law is a body of law that was first developed in the English courts based on custom and general principles, and set forth in court opinions. In time, much of the common law was put into statutory form, or "codified," so now, many common law principles are represented in our statutes. Some states have much more codified law than common law, such as California, which has a statutory code to cover almost every aspect of human existence! Where there is no controlling statute, however, the common law, found in published court opinions, establishes what the law is.

• Research Tip: Court opinions are published in bound volumes called reporters, some of which contain the decisions of a single jurisdiction, while others contain the decisions of several courts, grouped together by geographic region. The citation that corresponds to a published opinion consists of the reporter volume number, the abbreviated name of the reporter, and the page number on which the case report (the opinion) begins. The year the decision was rendered also typically follows the citation, and appears in parentheses. An example of such a citation is 501 U.S. 560 (1991), which indicates the case Barnes v. Glen Theatre, Inc., decided in 1991, is published in volume 501 of the U.S. Supreme Court reporter, and begins on page 560.

The Roles of U.S. State and Federal Courts

If you are contemplating filing a lawsuit, you need to determine what court would have jurisdiction over the the issues in dispute. Will it be a federal or state court? Because most of our day-to-day lives are governed by state statutes and regulations, the great majority of legal disputes in American courts are heard in state court systems. For example, state courts have jurisdiction over virtually all divorce and child custody matters, probate and inheritance issues, real estate questions, and juvenile matters, and they handle most criminal cases, contract disputes, traffic violations, and personal injury cases.

However, a growing number of subjects may also be regulated by both state and federal statutes, including consumer protection, employment, and food and drug regulation. Where both state and federal laws seem applicable to a situation, often state law will not control and will give way to federal law due to the doctrine of "preemption."

Both the federal and state court systems are essentially three-tiered. The lowest level is generically called the "trial level." This is where a case is initially heard, and results in a decision by either a judge or a jury. A party must request a jury trial if it wants one, and if no party requests a jury trial, the judge alone will decide the case following a "bench trial." Most cases, however, are resolved before going to trial, either by settlement, voluntary dismissal or by the court ruling, following a motion brought by one of the parties, that one party cannot win the case as a matter of law. (A ruling on such a motion may be appealed, as will be discussed below).

State Courts
The state trial courts are referred to by various names throughout the U.S., such as the circuit court (IL), superior court (CA), and supreme court (N.Y.), and are often organized by county. When a final judgment is entered by the trial court, it is usually in the form of an "order." These judgments are generally not published and do not create new law, except with respect to the given case.

Following the entry of a final judgment, if a party wishes to appeal the judgment entered by the trial court, it typically files an appeal with the state's intermediate appellate court. Not every appeal filed is necessarily accepted by the appellate court, and the rules on appellate jurisdiction vary from state to state.

• Note: On appeal, there is not a new trial of the case; rather, lawyers for the parties submit legal briefs, in which they make arguments as to why the trial court judgment should or should not be upheld. Often, the lawyers are allowed to present their arguments verbally to the appellate court at "oral argument." In considering the parties' positions, the appellate court reviews all of the materials filed with the trial court and made part of the "record" that lead to the trial court's decision. It then determines what the law is, by analyzing the various sources of law discussed above.

Once the appellate court reaches its decision, it may elect to issue an order, an unpublished opinion, or a published opinion. The court my uphold ("affirm") the trial court judgment, overturn ("reverse") it, affirm and reverse it in parts, and/or remand the case to the trial court for further proceedings, which may even include a new trial.

• Note: State appellate court decisions are not binding in other states, but may be considered as persuasive authority in a state that has not yet established a rule of law on the given issue. If you live in a state that does not have a statute or case law addressing your particular issue, you may argue that a rule announced by an appellate or supreme court of another state, under similar circumstances, should be adopted by the court in your state.

If a party wishes to appeal the decision of the intermediate appellate court, it files an appeal with the state's highest appellate court, usually known as the state supreme court. However, as might be expected, state supreme courts accept only a small percentage of the cases submitted to them, and apply certain jurisdictional rules and other criteria in deciding whether to accept an appeal. Thus, in many instances, the intermediate appellate court is the last stop for a case. (There are certain types of cases, such as those where the death penalty is imposed, that are directly appealable from the trial court to the state supreme court).

If the state supreme court accepts an appeal, the parties again submit legal briefs and may be permitted to present oral arguments to the court. In reaching a decision, the supreme court reviews the trial, as well as the appellate, court records, the law, and also considers state-wide policy in rendering its decision. The state supreme court may issue its decision in the form of an order, an unpublished opinion, or a published opinion. Published opinions are precedential and establish the law for the entire state. In limited situations, where a state supreme court case involves a Constitutional issue, it may be appealed to the U.S. Supreme Court.

Federal Courts
Federal courts have the authority to hear only certain types of cases. Under their "federal question jurisdiction," federal courts may hear cases that involve the United States government, the United States Constitution or federal laws, or controversies between states or between the United States and foreign governments. There are certain types of cases that are heard exclusively by federal courts, such as those arising from bankruptcy, copyright, patent, and Social Security laws. Under their "diversity jurisdiction," federal courts may hear cases between parties that are citizens of different states, or between United States citizens and those of another country, where the potential damages recovery exceeds $75,000. Diversity cases with claims below that amount may only be pursued in state court. Any diversity case, regardless of the amount of money involved, may be brought in a state court rather than a federal court. This is because diversity cases do not necessarily involve any federal law.

What Are Federal District and Circuit Courts?
The federal court system is also three-tiered (with the exception of the bankruptcy courts, which have a slightly different configuration). The lowest level courts, the "trial courts," are called "district courts." There are 94 federal judicial districts, including at least one district in each state, the District of Columbia and Puerto Rico. In contrast to state trial court decisions, most federal district court decisions are published in legal reporters (see above). A party who wishes to appeal a decision of a federal district court files an appeal with the intermediate federal appellate court, known as a circuit court, for that district.

There are 13 federal judicial circuits in the United States, each with a court of appeals. A circuit court hears appeals from the district courts located within its circuit, as well as appeals from decisions of federal administrative agencies. In addition, the Court of Appeals for the Federal Circuit has nationwide jurisdiction to hear appeals in specialized cases, such as those involving patent laws and cases decided by the Court of International Trade and the Court of Federal Claims. A party wishing to appeal a circuit court decision appeals to the U.S. Supreme Court.

• Research Tip: Not sure what federal district or circuit court has jurisdiction in your area? The U.S. Federal Judiciary web site has interactive maps and links, grouped by geographic area to help you.