Homeowners' liability for injuries suffered on their property will vary depending on the legal rules in place in the state where the injury occurred. In some states, the court will focus on the status of the injured visitor in determining the liability of the owner or occupier, i.e. whether that person was an "invitee", "licensee", or "trespasser".
When a homeowner invites or induces others to enter the premises for any lawful purpose, this triggers the homeowner's duty to exercise ordinary care to keep the premises safe. An invitation may be expressed (i.e. through words such as "please come in"), implied from known customs or use of the premises, or inferred from the homeowner's conduct. Contractors are typically considered invitees.
A licensee is a person who has no contractual relation with the property owner, but who is permitted -- expressly or implicitly -- to be on the premises. A social guest at a residence is normally considered a licensee. The homeowner is usually liable only for willful or wanton injury to a licensee. This means that the homeowner is required to exercise enough care to prevent injury to a licensee who is actually known to be -- or could reasonably be expected to be -- within the range of a dangerous act or condition.
Surprising to many homeowners is the fact that a duty of care is also owed to people who have no permission or lawful right to be on the premises. A trespasser is a person who enters the premises of another without express or implied permission of the owner, for the trespasser's own benefit or amusement. A homeowner cannot lawfully prepare pitfalls or traps for a trespasser in order to purposefully injure the trespasser. Once the owner is aware of the trespasser's presence or can reasonably anticipate such presence from the circumstances -- evidence of skateboarders in an unfinished swimming pool would fall into this category -- then the owner has a duty to exercise ordinary care to avoid injuring the trespasser.
Learn more in the Premises Liability section of FindLaw's Accident & Injury Center