Formally speaking, the elements of a personal injury claim are (i) duty (ii) breach of duty (iii) causation and (iv) damages. In most cases, the defendant is thought to have a duty of “ordinary care” toward the victim – a motorist, for example, is expected to drive safely. If the defendant breaches that duty by, for example, running a stop light, the defendant is said to have acted negligently (carelessly).
If (and only if) running the stop light was a substantial cause of the car accident, the defendant will be liable to the victim for the damages that the victim suffered, including personal injuries. The victim must prove the extent of his or her damages, and he or she cannot recover for any damages that are unable to be proven. The issue of damages is often the most vigorously contested aspect of a personal injury case.