“Trespass” is an intentional tort that involves interfering with someone else’s rights. Originally, courts recognized three different types of trespass:
- Trespass to persons: An act that interferes with someone else’s rights over their body and freedom of movement, including assault, battery, and false imprisonment.
- Trespass to chattels: An act that interferes with someone else’s rights to use their personal property freely, such as conversion.
- Trespass to land: An act that interferes with someone else’s rights to use their real property freely. Some U.S. jurisdictions also recognize a criminal claim for trespass.
Today, the term “trespass” or “trespassing” usually refers to an intentional act that interferes with someone else’s rights to use their real estate. Trespass does not always have to involve harm to the land or to its monetary value. For instance, merely walking across someone else’s yard without permission may be seen as trespassing because it interferes with the owner’s right to decide who may come on the land and who must stay out.
Walking or driving onto someone else’s real estate without permission is perhaps the most obvious example of trespass. However, trespass can also occur if someone else’s trash, tree branches, or other objects are placed or thrown onto the land, even if the person who leaves them there never sets foot on the land himself. Trespass can also occur when someone who has permission to enter land does impermissible things while on the land, or has his permission revoked while he’s on the land.
For example, suppose that a horse owner lives next door to a man who has several acres of forest. The horse owner asks the forest owner for, and gets, permission to ride her horse in the neighbor’s woods. However, after several months the horse owner decides to start leaving her trash bags in the neighbor’s woods. The neighbor may hold the horse owner liable for trespassing because she did not have permission to leave her trash in his woods, even though she had permission to ride her horse through them. Likewise, if the neighbor encounters the horse owner in the woods one day and tells her, “get off my land,” the horse owner is trespassing if she refuses to leave or if she comes back later without permission.
Unlike claims for assault, conversion, and similar acts, the property owner does not have to prove he suffered actual damages in order to hold someone liable for trespass. Instead, a plaintiff in a trespass case must only prove that the defendant intentionally entered onto or otherwise interfered with the plaintiff’s use of his land.
Today, most U.S. courts require a trespass to be intentional. Most courts will not find that someone who entered or damaged someone else’s land negligently is liable for trespass, although he may be liable for the cost of repairs or other damages. Some courts make an exception for people who negligently enter or damage land while conducting an ultrahazardous activity. Most U.S. courts also recognize an exception for rescue situations, such as when a car veers into someone’s front yard in order to avoid hitting a pedestrian.
Places in which an intruder can be held liable for trespass include more than just the surface of the land itself. They also include any buildings on the land, the subsoil, and a limited amount of air space, usually that space that is closest to the ground. For example, a landowner may not be able sue an airline company for trespass when its jets fly over his house at 10,000 feet, but he may be able to sue a construction company that lets the hooks on its cranes dangle six feet over the roof of his house.