What is negligence in law?

The four elements, in order

1. Duty. Did the defendant owe you care at all? Drivers owe it to everyone on the road; property owners owe it to lawful visitors; doctors owe it to patients; employers owe it to workers and often to the public their workers deal with.
2. Breach. Did their conduct fall below that standard? The yardstick is the “reasonable person,” not the defendant's own best intentions. For professionals it rises to what a competent professional in that field would have done.
3. Causation. Two questions in one: would the harm have happened anyway (cause in fact), and was this harm a foreseeable result of the conduct (proximate cause)?
4. Damages. Something measurable must have been lost — treatment, income, property, or the documented pain of recovery. Carelessness that injures nobody is not a lawsuit.

Who is the “reasonable person”?

A legal fiction: an ordinary, prudent adult who pays attention, follows safety rules and takes precautions in proportion to the risk. The standard is objective. A driver who is doing their honest best but is tired, lost or inexperienced is still measured against the reasonable driver. Children are usually measured against a reasonable child of the same age, except when they do adult activities such as driving. People with a physical disability are measured against a reasonable person with that disability.

Courts also weigh cost against risk. The more likely and serious the harm, and the cheaper the precaution, the more clearly a failure to take it is a breach. A store that leaves a spill on the floor for an hour has little excuse; one that has a spill for thirty seconds before someone slips may have none to answer for.

Where cases are actually won and lost

Duty is rarely contested. The fight is usually over breach and causation, and it is a fight about evidence: dash-cam footage, maintenance logs, a 911 recording, phone records showing a driver was texting, the inspection report on a stairwell. Evidence decays fast — video is overwritten in days, a damaged vehicle is scrapped, a wet floor is mopped — which is why the first weeks matter more than the first hearing.

Negligence per se

When a defendant broke a safety statute — ran a red light, served alcohol to a minor, ignored a building code — many states treat the breach element as already proved. You still have to show the statute was meant to protect people like you from harm like yours, and that the violation caused the injury.

Ordinary vs. gross negligence

Gross negligence is a conscious disregard of an obvious risk — driving at twice the speed limit through a school zone, for example. The label matters because some protections, such as Good Samaritan laws, liability waivers and certain government immunities, cover ordinary negligence but not gross negligence, and because gross negligence can open the door to punitive damages.

Shared blame

Being partly at fault does not automatically end a claim. Under pure comparative fault you recover your share even at 90 percent blame. Under modified comparative fault, the rule in most states, you recover only if your share stays below 50 or 51 percent. Under contributory negligence, still the rule in Alabama, Maryland, North Carolina, Virginia and the District of Columbia, any blame at all can bar recovery. Insurers know this, so expect them to argue that you were looking at your phone, speeding or wearing the wrong shoes.

Other defenses you may hear about

• Assumption of risk — you knowingly accepted a specific danger, as a spectator hit by a foul ball at a ballpark often is held to have done.
• Signed waivers — enforceable in many states for ordinary negligence at gyms or adventure sports, but rarely for gross negligence.
• Immunity — government bodies and some charities enjoy full or partial immunity, often with strict notice deadlines as the price of suing them.

What to do if you were hurt by someone's carelessness

See a doctor promptly and follow the treatment plan; gaps in care are the insurer's favorite argument. Write down what happened while you remember it, photograph the scene, get witness contacts, and ask in writing that any video be preserved. Then talk to a personal injury lawyer before the statute of limitations — commonly two or three years — runs out.