In legal terms, a personal injury case is a legal dispute that comes about because one person suffers harm due to an accident or injury that another person may be liable for causing. While a personal injury case can proceed through civil court proceedings in order to determine fault by means of a definitive court judgment, it is much more common that these cases are resolved through informal settlement before any lawsuit is filed.

Personal injury cases differ from criminal court actions, which are brought about by the government. Civil cases begin when a private individual (referred to as the "plaintiff") files a civil complaint against another party (referred to as the "defendant), which could be a person, business, corporation, or government agency. The complaint alleges that the defendant acted in a careless or irresponsible manner in regard to the accident, ultimately causing injury. This is the filing of the lawsuit. 

Informal settlements are carried out by those personally involved in the dispute, their insurers, and attorneys representing both sides.  These settlements are usually carried out as negotiations which proceed after both sides have signed a written agreement, declaring that they will not pursue further legal actions, instead resolving the dispute through the payment of an agreed upon amount of money. 

Most personal injury lawsuits fall under the jurisdiction of state courts in the county where the injury occurred or where parties involved in the incident are located. Cases involving a quantity of money below some pre-established limit (usually between $2,000 and $5,000) must be filed under the small claims division of the court.  

In cases where the parties involved in the personal injury case reside in different states and the amount of money involved in greater than $75,000, the jurisdiction law does not apply. These cases may be filed under federal jurisdiction in the U.S. District Courts, or the case may be moved to them if it was originally filed in a state court.  As the nuances of determining jurisdiction and the consequences of different jurisdictions can be quite complicated and consequently, it is advisable to consult an experienced attorney who can determine the best jurisdiction within which to file the case. 

The law governing personal injury cases, unlike most other legal issues, is primarily derived from court decisions and legal treatises, rather than an established code. While many states have begun to summarize the development of personal injury law in written statutes, for all practical purposes, court decisions remain the primary source of the law in personal injury cases. Note than in issues where a code is clearly relevant, such as automobile accidents, this can be used to help determine the fault in the personal injury case.