Definition of Writ:
“(bef. 12c.) A court’s written order, in the name of a state or other competent legal authority, commanding the addressee to do or refrain from doing some specified act.”
United States Law:
Early law of the United States inherited the traditional English writ system, in the sense of a rigid set of forms of relief that the law courts were authorized to grant. The All Writs Act passed in 1789 authorizes United States federal courts to “issue all writs necessary or appropriate in aid of their respective jurisdictions & agreeable to the usages & principles of law”. However, the Federal Rules of Civil Procedure, adopted in 1938 to govern civil procedure in the United States district courts, provide that there is only one form of action in civil cases, & explicitly abolished certain writs by name.
All Writs Act:
U.S. Code Title 28 — JUDICIARY AND JUDICIAL PROCEDURE
PART V — PROCEDURE
CHAPTER 111 — GENERAL PROVISIONS
§ 1651. Writs
(a) The Supreme Court and all courts established by Act of Congress may issue all writs necessary or appropriate in aid of their respective jurisdictions and agreeable to the usages and principles of law.
(b) An alternative writ or rule nisi (“to show cause”) may be issued by a justice or judge of a court which has jurisdiction. 
Excerpt from W.S. Holdsworth’s Sources and Literature of English Law:
“Writs have a long history. We can trace their formal origin to the Anglo-Saxon formulae by which the king used to communicate his pleasure to persons & courts. The Anglo-Norman writs, which we meet with after the Conquest, are substantially the Anglo-Saxon writs turned into Latin. But what is new is the much greater use made of them, owing to the increase of royal power which came with the Conquest.”
Definition of Writ System:
“(1890) The common-law procedural system under which a plaintiff commences an action by obtaining the appropriate type of original writ.”
Definition of Process:
“n. (14c.) 1. The proceedings in any action or prosecution <due process of law>. 2. A summons or writ, especially to appear or respond in court <service of process>. – Also termed judicial process; legal process.“
History & Development:
In its earliest form a writ was simply a written order made by the English monarch to a specified person to undertake a specified action; for example, in the feudal era a military summons by the king to one of his tenants-in-chief to appear dressed for battle with retinue at a certain place & time.
The development of writs as a means of commencing a court action was a form of “off the- shelf” justice designed to enable the English law courts to rapidly process lawsuits by allocating each form of complaint into a standard category which could be dealt with by standard procedures. The complainant (person who files the complaint) simply applied to the court for the writ most relevant to his complaint to be sent to the wrongdoer, which ordered him under royal authority to attend a royal court to answer for his actions. The development was part of the establishment of a Court of Common Pleas, for dealing with commonly made complaints by subjects of the crown, for example: “someone has damaged my property”.
The previous system of justice at the royal court of Chancery was tailor-made to suit each case & was thus highly time-consuming. The writ was “served” on (delivered in person to) the wrongdoer & acted as a command that he should appear at a specified time & date before the court specified in the writ, or it might command some other act on the part of the recipient.
Where a plaintiff wished to have a case heard by a local court, or by an Eyre if one happened to be visiting the County, there would be no need to obtain a writ. Actions in local courts could usually be started by an informal complaint. However, if a plaintiff wished to avail himself of Royal— and by implication superior— justice in one of the King’s courts, then he would need a writ, a command of the King, to enable him to do this. Initially for common law, recourse to the King’s courts was unusual, & something for which a plaintiff would have to pay. While originally writs were exceptional, or at least non-routine devices, Maitland suggests that by the time of King Henry II (1154-1189), the use of writs had become a regular part of the system of royal justice in England.
With the abolition of the Forms of Action in 1832 and 1833, a profusion of writs was no longer needed, & one uniform writ came into use. After 1852 the need to state the name of the form of action was also abolished. In 1999 the Woolf Reforms unified most of the procedure of the Supreme Court & the County Court in civil matters. These reforms brought in the Civil Procedure Rules. Under these almost all civil actions, other than those connected with insolvency, are now commenced by the completion of a ‘Claim Form’ as opposed to the obtaining of a ‘Writ’, ‘Originating Application’, or ‘Summons’ (see Rules 7 and 8 of the Civil Procedure Rules).
Relief formerly available by a writ is now normally available by a lawsuit (civil action) or a motion in a pending civil action. Nonetheless, a few writs have escaped abolition & remain in current use in the U.S. federal courts:
- The writ of habeas corpus, usually used to test the legality of a prisoner’s detention, has expressly been preserved. It is explicitly mentioned in the United States Constitution (Art. 1, § 9, cl. 2) In the United States federal courts, the writ is most often used to review the constitutionality of criminal convictions rendered by state courts. The writ’s application does not stop there: the Supreme Court has held the writ of habeas corpus open to all individuals held by the federal government, including Guantanamo Bay detainees. See Boumediene v. Bush.
- By statute, the Supreme Court of the United States uses the writ of certiorari to review cases from the United States courts of appeals or from the state courts.
- In extraordinary circumstances, the United States court of appeals can use the common law writ of prohibition under the All Writs Act to control proceedings in the district courts.
- Some courts have held that in rare circumstances in a federal criminal case, a United States district court may use the common law writ of error coram nobis under the All Writs Act to set aside a conviction when no other remedy is available.
- The United States district courts normally follow state— in the United States federal courts but are almost never used in practice. In modern times, the All Writs Act is most commonly used as authority for federal courts to issue injunctions to protect their jurisdiction or effectuate their judgments.
The situation in the courts of the various U.S. states varies from state to state but is often similar to that in the federal courts. Some states continue to use writ procedures, such as quo warranto, that have been abolished as a procedural matter in federal courts. In an attempt to purge Latin from the language of the law, California law has for many years used the term writ of mandate in place of writ of mandamus, and writ of review in place of writ of certiorari.
: All definitions throughout this page from Black’s Law Dictionary Deluxe Tenth Edition by Henry Campbell Black & Editor in Chief Bryan A. Garner. ISBN: 978-0-314-62130-6
: US House of Representatives’ Office of Law Revision Counsel, “U.S. Code Title 28 — JUDICIARY AND JUDICIAL PROCEDURE
PART V — PROCEDURE
CHAPTER 111 — GENERAL PROVISIONS
§1651. Writs”: http://uscode.house.gov/view.xhtml?path=/prelim@title28/part5/chapter111&edition=prelim
: W.S. Holdsworth, Sources and Literature of English Law 20 (1925)
: Joseph Chitty’s A Practical Treatise on the Criminal Law
: C.J.S.’s Process
: Article One of the United States Constitution
: All “Writs”, Black’s Law Dictionary Deluxe Tenth Edition pages 1845-1849