Rule 2251.Definitions.

The chapter on joinder of additional defendants lets a party bring in a nonparty who may be liable on the claim against it. Under Rule 2252(a), that is a person who may be solely liable on the underlying cause of action, or liable to or with the joining party on a claim arising out of the same transaction or occurrence. The opening rule has one definition: an “action” is any civil action or proceeding brought in or appealed to any court of record that is subject to these rules.

The Official Note preserves some history. As first adopted in 1939, the rule also defined “defendant” to include any party originally named as a defendant, any plaintiff against whom a counterclaim or setoff is asserted, and any party later added to the record. That definition is gone from the current text; Rule 2252(a) now says directly that any party may join an additional defendant.

Rule 2253 sets the deadline for joinder, and Rule 2255 treats the joining party and the additional defendant, for procedure and pleadings, as plaintiff and defendant. The rule was last amended effective July 1, 2004.