Every entry on lands without the owner's leave, or authority of law, is a trespass.

Explanation

(English-origin maxim.) The right to exclude others from one's land is among the most ancient rights secured by the common law — any unauthorized entry, whether by a private party or a government agent acting without lawful warrant or the owner's consent, constitutes a trespass actionable at law regardless of whether actual damage is shown.

Where this applies

• A code enforcement officer walks onto a homeowner's property without a warrant or the owner's permission to inspect a fence, and the entry itself is a trespass.
• A neighbor cuts through someone's backyard as a shortcut without asking, and even though no damage is done, the unauthorized entry is actionable.
• A utility company sends workers onto private land without an easement or the owner's consent, and the landowner sues for trespass regardless of whether anything was damaged.