TRESPASS, in law, is any transgression of the law less than treason, felony, or misprision of either. The term includes a great variety of torts committed to land, goods, or person, distinguished generally by names drawn from the writs once used as appropriate to the particular trans-gression, such as vi et armis, quare clausuni f regit, de bonis asportatis, de uxore abducta cum bonis viri, quare filium et heredem rapuit, &c. Up to 1694 the trespasser was regarded, nominally at any rate, as a criminal, and was liable to a fine for the breach of the peace, commuted for a small sum of money, for which 5 W. and M. c. 12 sub-stituted a fee of 6s. 8d. recoverable as costs against the defendant. Trespass is not now criminal except by special statutory enactment, e.g., the old statutes against forcible entry, the Game Acts, and the private Acts of many rail-way companies. When, however, trespass is carried suffi-ciently far it may become criminal, and be prosecuted as assault if to the person, as nuisance if to the land. At one time an important distinction was drawn between trespass general and trespass special or trespass on the case, for which see TORT. The difference between trespass and case was sometimes a very narrow one ; the general rule was that where the injury was directly caused by the act of the defendant the proper remedy was trespass, where indirectly, case. The difference is illustrated by the action for false imprisonment: if the defendant himself imprisoned the plaintiff the action was trespass; if a third person did so on the information of the defendant it was case. A close parallel is found in Roman law in the actio directa under the lex Aquilia for injury caused directly, the actio utilis for that caused indirectly. One of the reasons for the rapid extension of the action on the case, especially that form of it called assumpsit, was no doubt the fact that in the action on the case the defendant was not allowed to wage his law (see WAGER).

In its more restricted sense, trespass is generally used for entry on land without lawful authority by either a man, his servants, or his cattle. To maintain an action for such trespass the plaintiff must have possession of the premises. The quantum of possession necessary to enable him to bring the action is often a question difficult to decide. In most instances the tenant can bring trespass, the reversioner only case. By the Judicature Act, 1873, a mortgagor in possession can sue for trespass in his own name. Remedies for trespass are either judicial or extra-judicial. The most minute invasion of private right is trespass, though the damages may be nominal if the injury was trivial. On the other hand, they may be exemplary if circumstances of aggravation were present. Pleading in the old action of trespass was of a very tech-nical nature, but the old-fashioned terms alia enormia, replication de injuria, new assignment, &c, once of such frequent occurrence in the reports, are of merely historical interest since the introduction of a simpler system of pleading, unless in those American States where the old pleading has not been reformed. The VENUE (q.v.) in trespass was formerly local, in case transitory. In addi-tion to damages for trespass, an injunction may be granted by the court. The power to grant injunctions against threatened or apprehended trespass has been considerably enlarged by the Judicature Act, 1873. The principal instances of extra-judicial remedies are distress damage feasant of cattle trespassing, and removal of a trespasser without unnecessary violence, expressed in the terms of Latin pleading by molliter manus imposuit.

Trespass may be justified by exercise of a legal right, as to serva the process of the law, or by invitation or licence of the owner, or may be excused by accident or inevitable necessity, as deviation from a highway out of repair. Where a man abuses an authority given by the law, his wrongful act relates back to his entry, and he becomes a trespasser ab initio, that is, liable to be treated as a trespasser for the whole time of his being on the land. Mere breach of contract, such as refusal to pay for wine in a tavern which a person has lawfully entered, does not constitute him a trespasser ab initio. A trespass of a permanent nature is called a continuing trespass; such would be the permitting of one's cattle to feed on another's land without authority.

In Scots law trespass is used only for torts to land. By the Trespass (Scotland) Act, 1865, trespassers are liable on summary conviction to fine and imprisonment for encamping, lighting fires, &c, on land without the consent and permission of the owner.