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What Is the Difference Between Negligence and Negligence Per Se?

Posted on August 15th, 2017

In a case involving a personal injury that someone else caused, one might encounter the legal doctrines of “negligence” or “negligence per se.” These are two entirely separate legal theories that involve different standards of proof on the plaintiff’s part. Learning the difference between these two doctrines can go a long way toward understanding your particular case in Pennsylvania. The focus of the lawsuit will shift depending on the proximate cause of the accident.


By law, “negligence” is the failure to use reasonable care, resulting in someone else’s injuries or damages. The definition of “reasonable care” depends on the situation. What qualifies as reasonable will change according to the defendant’s role in the accident and the accepted standards of care in a particular situation. In the medical field for example, physicians owe their patients the highest duties of care. Many actions could put patients at unreasonable risks of harm, all of which the law might consider negligence.

Deciding whether someone was negligent typically requires a heavy burden of proof. The plaintiff must show the defendant owed a duty of care, breached this duty, and therefore caused the accident and injuries. This process may require an in-depth investigation, expert witness testimony, eyewitness accounts, and other forms of evidence of the defendant’s negligence.

To deem that a defendant was “negligent,” the courts will ask whether another reasonable and prudent individual or entity in similar circumstances would have done the same thing. This may take interviews with professionals in the same industry who have similar experiences and backgrounds. In cases that center on negligence, the question of the defendant’s fault is largely up to the judge or jurors.

Negligence Per Se

Negligence per se is a distinct type of claim that centers on the violation of a specific law. In negligence per se cases, the plaintiff argues that the defendant’s negligence is obvious, or assumed, due to the fact that he or she broke the law. The idea behind negligence per se is that an act is negligent because it violates a law that’s in place to protect the public. Examples of laws that, if broken, could lead to these types of claims include:

  • Speed limits
  • Building codes
  • Blood alcohol content limits
  • Consumer product standards
  • Federal laws

Laws involved in negligence per se cases are often those that aim to protect the public at large. Proving negligence per se requires less work than typical negligence cases. It is often easier for the victim to recover compensation for damages. Negligence per se eliminates the need for a judge or jury to decide whether the defendant was reasonable in his or her actions. The jury assumes the actions were unreasonable since they broke the law. The jury must still decide whether the defendant’s conduct caused the accident, but the plaintiff does not bear the burden to prove a breach of standard of care.

In negligence and negligence per se lawsuits, proving liability can be difficult. Representation from a skilled personal injury attorney can make the process easier for injured victims. Regardless of the circumstances of your case, contact our West Chester injury attorneys for questions or a free case evaluation to maximize your chances of compensation.