Legal practice is sometimes used to distinguish the body of judicial or administrative precedents, rules, policies, customs, and doctrines from legislative enactments such as statutes and constitutions which might be called "laws" in the strict sense of being commands to the general public, rather than only to a set of parties.
In the legal practice that emerged in royal courts under Henry II any case had to fit into a narrowly defined form of pleading usually called a "writ". By the time of Henry III the number of such writs had grown to over 500, but even that many did not cover all the possible claims that people sought to make.
The Provisions of Oxford in 1258 forbade the royal clerks to create any new writs. The result of this was that the courts began to adopt "fictions" such as imaginary parties or actors so that the facts of a case could be fit within one of the established forms, and the Writ of Trespass came to become the catchall form for most claims.
It is important to understand that, unlike much current practice, the writs of pleading were not court orders granting relief but the summons, prepared by the plaintiff, filed with the court, and served on the respondent.
The nonconflicting parts of the English and American common law and its forms of pleading were explicitly incorporated into the U.S. Constitution.
In Suits at common law, where the value in controversy shall exceed twenty dollars, the right of trial by jury shall be preserved, and no fact tried by a jury, shall be otherwise re-examined in any Court of the United States, than according to the rules of the common law.
By the middle of the 19th century strong resistance developed to the rigidities of the common law forms of pleading brought over from England, whose monarchical forms often conflicted with U.S. republican law that made the people the sovereign.