Intentional Torts to Property and Defenses/Privileges

Trespass to Land, Trespass to Chattels, and Conversion

Trespass to land requires (1) an intentional act of physical invasion of (2) the plaintiff's real property. The defendant need only intend to enter the land (or cause a physical thing to enter) — she need not know the land belongs to another. Mistake about ownership or boundary lines is no defense. The invasion can be by the defendant personally, or by propelling a physical object onto the land (flooding a neighbor's basement, throwing rocks). Intangible invasions — noise, odors, light — are addressed through nuisance, not trespass.

The possessor of land (not necessarily the owner) is the proper plaintiff, and may recover nominal damages without proving actual harm. A trespasser is also liable for harm caused even if unforeseeable.

Trespass to chattels and conversion lie on a spectrum of interference with personal property:

The practical question is always how serious the interference is. Borrowing a neighbor's lawnmower without permission for an hour is trespass to chattels; keeping it for six months, selling it, or destroying it is conversion. Only tangible personal property (and documents in which rights are merged, like a stock certificate) can be converted. Mistake is not a defense to either tort.

Consent and the Defensive Privileges

Consent is a complete defense to all intentional torts. It may be express or implied (by custom, as on a contact-sports field, or by the plaintiff's apparent manifestation). Consent is invalid if obtained by fraud going to the essential nature of the act, by duress (threats of present force), or if the plaintiff lacks capacity (incompetents, young children, the intoxicated). A defendant who exceeds the scope of consent — the surgeon who, with consent to operate on the right ear, operates on the left — loses the privilege.

Self-defense: A person may use reasonable force to defend against an imminent or ongoing battery. The force must be proportionate. Deadly force may be used only if the actor reasonably believes she faces a threat of death or serious bodily harm. California imposes no duty to retreat before using force (the 'stand your ground' approach); the actor may even pursue an aggressor as reasonably necessary. A reasonable mistake about the need for self-defense does not destroy the privilege.

Defense of others mirrors self-defense: reasonable force to protect a third person the actor reasonably believes is entitled to defend herself. The modern (and California) rule allows the defense even if the actor was mistaken, so long as the mistake was reasonable.

Defense of property: One may use reasonable, non-deadly force to prevent a tort against her property, but only after a request to desist (unless the request would be futile or dangerous). Deadly force may NEVER be used merely to protect property. This is the famous Katko v. Briney spring-gun rule — a landowner cannot rig a trap gun to protect an unoccupied building. A defendant also loses the privilege against someone with a superior privilege, such as a person acting under necessity.

Necessity and Recapture

Necessity privileges what would otherwise be a trespass or interference with property when it is reasonably necessary to avoid a greater harm. It splits into two doctrines:

• Public necessity (acting to protect the community at large — e.g., destroying houses to stop a spreading fire) is an absolute defense. The defendant owes nothing, even for property destroyed.
• Private necessity (acting to protect oneself or one's own property) is a qualified defense. The defendant is not liable for the technical trespass and the landowner may not eject her, but the defendant must pay for any actual harm she causes. This is the rule of Vincent v. Lake Erie Transp. Co.: a shipowner who keeps his vessel lashed to a dock during a storm is privileged to stay, but must pay for the damage to the dock.

Recapture of chattels: An owner may use reasonable, non-deadly force to recapture a chattel only when in hot pursuit of one who took it wrongfully (e.g., by force or fraud). If the original taking was lawful (a bailee who simply overstays), force is not allowed — the owner must use legal process. The related shopkeeper's privilege (Cal. Penal Code § 490.5) lets a merchant detain a suspected shoplifter for a reasonable time, in a reasonable manner, on reasonable grounds — a frequent California essay overlay on false imprisonment.

Essay tip: When property defenses appear, sequence them: identify the underlying intentional tort first, then march through consent → self-defense/defense of others → defense of property → necessity → recapture, discarding each that does not fit. Examiners reward the candidate who explains why a privilege fails (e.g., deadly force used to protect property).