As a generic term, the written allegation of facts upon which a party to any legal proceeding founds his claim or demand or his answer or defense thereto. Used in a broader sense, the term signifies the system of legal rules and principles applicable to the written pleadings in a legal proceeding.

Pleading is only one of the successive steps in a proceeding at law by which one party asserts or enforces his rights against another, all together being comprehended by the term procedure. Originally the pleadings in an action at common law were oral, as is evidenced by many peculiarities of the common-law procedure of a later date; but as early as the reign of Edward III. we find that the pleadings were in writing and usually in Latin.

Pleading at law, however, ultimately developed into a system of highly technical and formal rules requiring the greatest precision in their application, and often by their very formality and rigidity defeating rather than aiding justice. Although remedial statutes were passed as early as the reign of Elizabeth, no attempt at a general reformation of the system was made until 4 William IV., c. 42, in 1834. At a later date in the United States various forms of statutory or code pleadings were adopted.

The principles upon which any system of pleading are necessarily based will, perhaps, be best understood by referring briefly to the more essential elements of the common-law system. The primary object of the pleadings in an action at common law was to raise a single issue or dispute upon either a point of law or of fact. In the former case a question was raised for decision by the court, usually after argument upon the question of law involved and submission of briefs by opposing counsel. In the latter, a question was raised for decision by the jury after hearing evidence tending on the one side to prove and on the other to disprove the fact in dispute. And upon the decision of the court or a verdict of the jury final judgment was entered determining the rights of the parties to the controversy.

The first step toward accomplishing the object of pleading after service of summons or mandate of the court upon the defendant was the filing of the declaration (known in modern practice as the complaint) in court. In the declaration the facts were required to be stated according to their legal effect only, and it was not permissible to set out the evidence on which the plaintiff relied. Owing to the tendency of the early lawyers to adopt fixed forms of statement and to their adherence to precedent, the declaration was required to conform to one of a limited number of rigid forms, and if a plaintiff could not adapt the state of facts upon which he based his right to recover to one of these forms, he was without remedy.

After the plaintiff had filed his declaration it was then incumbent upon the defendant to make some statement of his defense; otherwise, after a certain period, judgment would be taken against him by default. If the defendant conceived that the declaration, if taken as true, did not show sufficient grounds to justify the plaintiff's recovery (or, as it was said, did not state a cause of action), he could submit the question of its sufficiency to the court as a matter of law by filing a demurrer to the declaration.

If however, the defendant wished to deny any of the allegations contained in the declaration, he might do so by filing a formal denial, his pleading in that case being known as a plea by way of traverse. An issue of fact was thus raised for decision by the jury.

It might happen, however, that the defendant, while admitting the truth of all the allegations in the declaration, and admitting that it was legally sufficient, relied upon the existence of new or other facts sufficient to excuse him from the liability charged in the declaration, in which case his plea took the form of a confession and avoidance. The plaintiff might then plead, setting up either a demurrer to the plea or a denial with the effect already described; or he in turn might plead by way of confession and avoidance and thus cast upon the defendant the burden of pleading again. In every case the pleadings were thus continued until a single issue of law or fact was raised, and the determination of that issue determined the rights of the parties to the litigation. Any plea of a defendant, such as has been described, setting up some matter of defense to the plaintiff's claim was known as a plea in bar or as a plea to the merits. It might happen, however, that the defendant wished to insist upon some matter which, though not a complete defense to the plaintiff's claim, was sufficient to show that the action was brought in an improper manner, as that the plaintiff was a married woman and had not joined her husband as plaintiff, or that the court had no jurisdiction, or that the defendant was not properly named. Such a plea was known as a plea in abeyance. The effect of a plea in abeyance, if successful, was to cause a dismissal of the plaintiff's action without prejudice to a second action if properly brought. If unsuccessful the defendant was allowed to plead again to the merits.

The successive pleadings in an action, beginning with the plaintiff's pleading, were named the declaration, plea, replication, rejoinder, sur-rejoinder, rebutter, and sur-rebutter. Although theoretically possible, it was not usual for the proceedings to continue beyond the rebutter or sur-rebutter.

Upon the trial of an issue of fact, as the character of the issue was determined by the pleadings, it necessarily followed that the relevancy of all evidence offered at the trail was also primarily determined by the pleadings. Upon the entry of judgment all the pleadings in the case, together with the judgment constituting the judgment roll, were filed with the clerk of the court, thus constituting a complete permanent record of the case.

Owing to the highly technical and formal nature of the common-law system, the practice grew up of deciding the rights of litigants upon purely formal grounds, and judgment was frequently taken against a party upon demurrer because he had failed to state a perfectly valid claim or defense in the proper form. This was corrected to some extent by the statute of 27 Eliz., e. 5, sec. 1, which provided that no advantage should be taken of defects of form, except by a special demurrer which should state specifically the formal defect objected to. The statute 4 Anne, c. 16, sec. 1, was enacted for more effectively accomplishing this result, and 15 and 16 Vict., c. 76, sec. 50-52, abolished the special demurrer and required all defects of form to be taken advantage of by motion before trial. This is generally the modern practice. The statute of Anne referred to allowed the defendant to plead several pleas to the same declaration, thus breaking down to some extent the principle of singleness of issue. Through laxity of practice also the defendant was allowed in his plea to make use of a general denial, known as the general issue, the effect of which in most actions was ultimately not only to deny all the essential allegations of the declaration, but to allow the defendant at the trial to prove many matters of affirmative defense. An attempt was made by statute, 4 Wm. IV., C. 42, to avoid the confusion and the frequently illogical results of this complicated system by authorizing the judges of the common-law courts to adopt certain rules modifying the common law of pleading as it then existed. These rules, known as the Hilary rules, were promulgated in 1834 and had for their principal object the narrowing of the general issue so as to make it conform more closely to a logical denial of the allegations in the complaint. These rules, however, did not succeed in accomplishing the desired result, and seem only to have added to the confusion into which the subject had fallen. The law was substantially revised by 15 and 16 Vict., c. 76, and modern legislation has been enacted in all of the United States in which the common-law system has been retained.

Following are the more essential changes:

Matters of form are required to be taken advantage of by motion before trial, otherwise they are deemed to have been waived. Singleness of issue is not required, the defendant being allowed to use the general denial and to plead several matters by way of confession and avoidance. In many jurisdictions the number of successive pleadings is limited. Decisions upon demurrers are not necessarily final, the defendant being usually allowed to plead to the merits in case his demurrer is over-ruled.

Great freedom of amendment is allowed, a party being allowed to correct a defective pleading by amendment on application to the court, even at the trial of the action, if the rights of his opponent will not be prejudiced by the amendment. There are also many minor changes, the general object being to make the system more simple and just in its application, and to avoid the determination of rights upon purely formal grounds.

Pleading at Criminal Law

At common law pleading in criminal actions was in its essentials substantially like pleading in civil actions, although much less elaborate.

The first pleading was called the indictment. To this the accused might interpose a demurrer, as in civil actions, and with like effect, except that if the demurrer were over-ruled he was allowed to plead to the indictment. All matters tending to show that the accused was not guilty of the offense charged might be shown under the oral plea not guilty or the plea nolo contendere, which was equivalent to guilty, except that it was not an admission by the defendant which could be used against him in evidence in a civil suit for the same act. After the plea no further pleading was necessary. The Plea of abatement or previous conviction or acquittal of the same offense were required to be specifically pleaded as a plea by way of confession and avoidance; and to these the prosecution might demur with the same effect as a demurrer to a plea in abatement in a civil action.

Pleading at criminal law has been subjected to fewer statutory changes than pleading in civil actions. In some States less formality is required than at common law, and final judgment cannot be entered upon purely formal grounds. Formal defects may be cured by amendment, but there can be no amendment to matter of substance in an indictment, otherwise an amended indictment would not satisfy the requirement that the indictment must be found by the grand jury.