The civil lawsuit requires the presence of two parties, as a general rule, at least, which are the plaintiff and the defendant, and since the plaintiff is the one who initiates the lawsuit and determines its scope, whether in terms of the subject, the parties, or the reason, except that the exception is that this effect extends to persons who are not a party, and the intervening party may have an interest or related to it, and third parties may play a role in that lawsuit pending before the court in one way or another.For the validity of procedures for the intervention of third parties in civil lawsuits, several controls are stipulated by the Iraqi legislator and comparative legislation, among them that there is a link between the third party involved and the subject matter of the lawsuit brought before the judiciary. from him. And that the intervention, according to the general rules, must appear before closing the pleading door, and it should not be misplaced. The Iraqi legislator and comparative legislation set a time when third parties should intervene, so by closing the pleading door, there is no room for a third person to interfere in the litigation.