In law, a failure to do something required by duty is called nonfeasance, and it can create the same liability as actively causing harm — but only when a specific legal duty applied to you, your inaction caused real injury, and a court recognizes the connection. Moral failure isn’t enough. The law has to have put the obligation on you in the first place.
When the Law Actually Imposes a Duty
A legal duty is an enforceable obligation you owe to someone else. It comes from one of three places, and if none of them applies, there is no duty to breach.
Statutes are the clearest source. Legislatures write duties directly into law: traffic codes require drivers to signal, yield, and stop; the Occupational Safety and Health Act requires employers to keep workplaces free from recognized serious hazards; tax codes require returns. When a statute spells out what you must do, violating it can be treated as automatic evidence of a breach.
Contracts create duties you accept voluntarily. A contractor agrees to finish a building. A landlord agrees to maintain habitable conditions. A vendor agrees to deliver by a deadline. Failing to perform at all is nonfeasance in the contract setting and gives the other party grounds for a breach-of-contract claim.
Common law supplies the rest. Courts have long recognized a general duty to exercise reasonable care so your actions don’t create an unreasonable risk of physical harm to others. Whether that duty exists in a particular case is a question of law the judge decides. It applies whenever your conduct creates a foreseeable risk of injury.
Why Doing Nothing Usually Isn’t Illegal
Most people assume that watching someone get hurt and not helping must be against the law somewhere. Under the common law, it generally isn’t. If you did not create the danger and have no special relationship with the person in trouble, you typically owe no legal duty to intervene. A bystander who watches someone drown may be morally reprehensible, but in most situations, the bystander has broken no law. Courts have consistently held that a moral obligation does not, by itself, create a legal duty to act.
A small number of states have passed statutes requiring bystanders to call for help or provide reasonable assistance in certain emergencies, with penalties that tend to be modest fines or misdemeanors. These remain the minority rule.
The no-duty-to-rescue rule has important exceptions even where no rescue statute exists:
- Once you voluntarily begin helping someone, you take on a duty to act with reasonable care and cannot leave them worse off than you found them.
- Special relationships create affirmative duties: parents to children, employers to employees, schools to students, innkeepers to guests.
- If your own conduct created the dangerous situation, you have a duty to take reasonable steps to prevent further harm.
Nonfeasance Versus Misfeasance
A breach of duty happens when someone falls short of what the law required. The shortfall takes one of two forms, and the label changes what has to be proven.
Nonfeasance is the failure to act when a duty required action. A lifeguard who ignores a drowning swimmer. A doctor who fails to order an obvious diagnostic test. A trustee who neglects to manage trust assets. In tort law, a nonfeasance claim requires showing the defendant should have taken steps to prevent the harm and did not. In contract law, a complete failure to perform is nonfeasance and supports a breach-of-contract claim.
Misfeasance is different. It is doing something, but doing it badly or carelessly: a surgeon operating on the wrong knee, a driver running a red light, a contractor using substandard materials. There is an affirmative act, performed improperly.
Courts are generally more willing to impose liability for misfeasance than for nonfeasance. With nonfeasance, establishing that a duty to act existed in the first place is often the hardest part of the case.
What the Inaction Gets Measured Against
Once a duty is established, a court measures the defendant’s conduct against a standard. For most people, that standard is the hypothetical reasonable person: an objective test asking whether an ordinary, prudent person would have acted the same way given what the defendant knew or should have known. The test does not bend for someone who is naturally forgetful or chronically careless.
Professionals are measured against their field, not the public. A doctor’s conduct is compared to what a reasonable doctor would do; a lawyer’s to a reasonable lawyer’s. Holding a surgeon to the standard of an ordinary person would excuse errors any competent colleague would catch. When a professional falls below the standard of their field, the claim is typically called malpractice.
Fiduciaries face the highest standard. Trustees, corporate officers, business partners, executors, and agents acting under a power of attorney owe duties that go well beyond reasonable care, including obligations of loyalty and informed decision-making. A fiduciary who self-deals, conceals information, or neglects responsibilities can face both compensatory and punitive damages, and courts tend to scrutinize fiduciary conduct more harshly than ordinary negligence.
What Else You Have to Prove
Showing a breach is only the first element. A negligence claim also requires causation and damages, and if any piece is missing, the claim fails.
Causation
The breach must actually have caused the harm. Courts apply two tests. The first is “but-for” causation: would the injury have happened if the defendant had met their duty? If not, causation is established. The second is proximate cause, which asks whether the harm was a foreseeable consequence of the breach. A defendant is only responsible for harms a reasonable person could have anticipated. An unforeseeable intervening event can break the chain.
Damages
You must have suffered actual harm. A breach that injures no one is not actionable. If a nurse administers the wrong dose but the patient suffers no adverse effects, there is no negligence claim despite the clear departure from the standard of care. The harm typically needs to be physical injury or property damage; purely economic losses without accompanying physical harm usually will not satisfy this element. Some states recognize standalone emotional distress claims, but that varies by jurisdiction.
Your Own Fault
If your carelessness contributed to the injury, your recovery may shrink or disappear. Most states follow some version of comparative negligence, which assigns each party a percentage of fault and reduces the plaintiff’s damages by their share. A jury that finds you 40 percent at fault and the defendant 60 percent at fault awards you 60 percent of your damages.
Most comparative negligence states impose a cutoff: if your fault reaches 50 or 51 percent, depending on the state, you recover nothing. A small number of states still follow the older contributory negligence rule, under which any fault on your part, even one percent, bars recovery entirely. Which rule your state follows can determine whether filing a claim makes sense at all.
What a Successful Claim Produces
The remedy depends on the type of duty breached and the seriousness of the harm.
Compensatory damages are the default. They aim to put you back in the financial position you would have been in without the breach, covering things like fair market value of damaged property, lost income, and necessary expenses such as medical bills. In contract cases, the goal is the same: restore the economic position the injured party expected from the deal.
Punitive damages go beyond that. Courts award them to punish especially harmful conduct and deter similar behavior. They are not available in ordinary negligence cases. You typically need to show the defendant acted intentionally or with reckless, willful disregard for your safety, and courts evaluate whether the punitive award is proportional to the compensatory damages.
Specific performance is a contract remedy where the court orders the breaching party to actually do what they promised. Courts reserve it for situations where money cannot make the injured party whole, such as real estate transactions or deals involving unique assets. Injunctions, which require or forbid specific conduct going forward, are available in some duty-based cases as well.
You Have to Limit Your Own Losses
Even after someone else breaches a duty owed to you, the law expects you to take reasonable steps to minimize your damages. If you refuse to follow a doctor’s treatment plan after an injury, a court may cut your award by the amount reasonable care would have prevented. The defendant bears the burden of proving you failed to mitigate, but the issue comes up constantly in litigation.
How Long You Have to File
Every breach-of-duty claim has a deadline, and missing it ends the claim regardless of how strong the evidence is. For negligence and personal injury, statutes of limitations across the states typically run from one to four years, with two or three years being the most common. Breach-of-contract claims usually allow more time, often four to six years.
The clock usually starts when the injury occurs, but not always. Under the discovery rule, the deadline may be paused until the injured person knew, or reasonably should have known, that they were harmed and that someone’s breach caused it. This matters in cases like medical malpractice, where a surgical error might not produce symptoms for months or years. The “reasonably should have known” piece puts a duty on you to investigate suspicious symptoms. If a reasonable person in your position would have looked into it and found the problem, the clock starts from that point, not from when you actually figured it out.
Professional malpractice claims sometimes carry shorter deadlines than general negligence. The specific window depends on your state and the profession involved, which is why checking your jurisdiction’s rules early is one of the most important steps after you suspect you have a claim.