Frivolous litigation, as used in colloquial and political terms in the United States, refers to lawsuits that are based on a theory that seems absurd, or where the claim results in damages that greatly exceed what one would expect from reading a brief summary of the case. Awards for medical malpractice are sometimes derided as frivolous (in this sense of meaning "excessive"). If a jury and a judge decided in favor of the plaintiff in such cases, the plaintiff's claim was not technically frivolous in legal terms, though it might be considered frivolous colloquially. Because of the ambiguity in the term, calling these lawsuits "frivolous" can lead to confusion because opposite sides of the tort reform debate can both say they oppose "frivolous" suits, with the tort reform supporters referring to the colloquial understanding, and tort reform opponents referring to the narrower technical definition. The typical definition in United States law is very different from its colloquial or political meaning. United States courts usually define "frivolous litigation" as a legal claim or defense presented even though the party and the party's legal counsel had reason to know that the claim or defense had no merit. A claim or defense may be frivolous because it had no underlying justification in fact, or because it was not presented with an argument for a reasonable extension or reinterpretation of the law, or because laws are in place unequivocally prohibiting such a claim (see Good Samaritan law). In the United States, Rule 11 of the Federal Rules of Civil Procedure and similar state rules require that an attorney perform a due diligence investigation concerning the factual basis for any claim or defense. Jurisdictions differ on whether a claim or defense can be frivolous if the attorney acted in good faith. Because a frivolous defense or claim wastes the court's and the other parties' time, resources and legal fees, sanctions may be imposed by a court upon the party or the lawyer who presents the frivolous defense or claim. The law firm may also be sanctioned, or even held in contempt.

Practice of Law

In its most general sense, the practice of law involves giving legal advice to clients, drafting legal documents for clients, and representing clients in legal negotiations and court proceedings such as lawsuits, and is applied to the professional services of a lawyer or attorney at law, barrister, solicitor, or civil law notary. However, there is a substantial amount of overlap between the practice of law and various other professions where clients are represented by agents. These professions include real estate, banking, accounting, and insurance. Moreover, a growing number of legal document assistants LDAs are offering services which have traditionally been offered only by lawyers and their employee paralegals. Many documents may now be created by computer-assisted drafting libraries, where the clients are asked a series of questions posed by the software in order to construct the legal documents.

In the United States, the practice of law is conditioned upon admission to practice of law, and specifically admission to the bar of a particular state or other territorial jurisdiction. The American Bar Association and the American Law Institute are among the organizations that are concerned with the interests of lawyers as a profession and the promulgation of uniform standards of professionalism and ethics, but regulation of the practice of law is left to the individual states, and their definitions vary.

In the United States, the rules of professional conduct generally prohibit an attorney from assisting a non-attorney from engaging in the unauthorized practice of law. An attorney therefore may not partner with or split fees with a non-attorney in the performance of any sort of legal work. Furthermore, an attorney may not employ a disbarred or suspended attorney in a legal practice where former clients of the disbarred or suspended attorney will be represented.