Negligence claims generally involve carelessness in taking an action, or failing to act, and require: (1) a legal duty owed by one person to another; (2) a breach of that duty; and (3) damages (injury) proximately caused by the breach.

Proximate cause has two components: (1) foreseeability and (2) cause-in-fact. Foreseeability requires that a person of ordinary intelligence should have reasonably anticipated the danger created by a negligent act or omission. Foreseeability is not measured by hindsight, but instead by what the actor knew or should have known at the time of the alleged negligence. Foreseeability requires only that the general danger, not the exact sequence of events that produced the harm, be foreseeable.

For a negligent act or omission to have been a cause-in-fact of the harm, the act or omission must have been a substantial factor in bringing about the harm, and absent the act or omission—i.e., but for the act or omission—the harm would not have occurred. If the defendant's negligence merely furnished a condition that made the injuries possible, there can be no cause in fact. There may be more than one proximate cause of an occurrence.

Negligence claims (a negligence cause of action) have long been recognized by judges in court opinions, and usually derive their authority from this common law, rather than from statutes enacted by state legislatures.

In Ohio, negligence claims are based on common law principles rather than specific statutes. To establish a negligence claim, a plaintiff must demonstrate that the defendant owed a legal duty to the plaintiff, breached that duty, and that the breach caused damages to the plaintiff. Proximate cause is a key element in negligence claims and includes two components: foreseeability and cause-in-fact. Foreseeability means that a person of ordinary intelligence should have anticipated the danger their actions or inactions could create. It is not judged in hindsight but in the context of what was known or should have been known at the time. The harm does not need to occur in a specific way, as long as the general danger was foreseeable. Cause-in-fact requires that the defendant's actions or omissions were a substantial factor in causing the harm, and that the harm would not have occurred 'but for' the defendant's negligence. If the negligence only created a condition that allowed for the injury to happen, it is not considered a cause-in-fact. There can be multiple proximate causes for an event. These principles are derived from judicial decisions over time and are recognized by Ohio courts when adjudicating negligence cases.