Civil procedure: Federal Rules of Civil Procedure: Joinder + indispensable party + Impleader + Intervention

In law, a joinder is the joining of two or more legal issues together. Procedurally, a joinder allows multiple issues to be heard in one hearing or trial and occurs if the issues or parties involved overlap sufficiently to make the process more efficient or fairer. That helps courts avoid hearing the same facts multiple times or seeing the same parties return to court separately for each of their legal disputes. The term is also used in the realm of contracts to describe the joining of new parties to an existing agreement.

Criminal procedure.

Joinder in criminal law refers to the inclusion of additional counts or additional defendants on an indictment. In English law, charges for any offense may be joined in the same indictment if those charges are founded on the same facts or form or are a part of a series of offenses of the same or a similar nature. A number of defendants may be joined in the same indictment even if no single count applies to all of them if the counts are sufficiently linked. The judge retains the option to order separate trials.

Civil procedure.

Joinder in civil law falls under two categories: joinder of claims and joinder of parties.

Joinder of claims.

Joinder of claims refers to bringing several legal claims against the same party together. In U.S. federal law, joinder of claims is governed by Rule 18 of the Federal Rules of Civil Procedure. These rules allow claimants to consolidate all claims that they have against an individual who is already a party to the case. Claimants may bring new claims even if these new claims are not related to the claims already stated; for example, a plaintiff suing someone for breach of contract may also sue the same person for assault. The claims may be unrelated, but they may be joined if the plaintiff desires.

Joinder of claims requires that the court have jurisdiction over the subject matter of each of the new claims, and that joinder of claims is never compulsory. A party who sues for breach of contract can bring his suit for assault at a later date if he chooses. However, if the claims are related to the same set of facts, the plaintiff may be barred from bringing claims later by the doctrine of res judicata, for example if a plaintiff sues for assault and the case is concluded, he may not later sue for battery regarding the same occurrence.