Consolidation of lawsuits may be ordered by a court when two or more lawsuits involving the same or similar parties (plaintiff and defendant), legal issues, and factual issues are pending in the same court or in different courts in the same jurisdiction (state court system or federal court system). If the lawsuits are pending in different courts one case may be transferred to the other court, and the cases consolidated there.

Laws and rules regarding the consolidation—or transfer and consolidation—of lawsuits vary from state to state and in the federal court system.

In Kansas, consolidation of lawsuits is governed by the Kansas Code of Civil Procedure. According to K.S.A. 60-242(a), when actions involving a common question of law or fact are pending before the court, it may order a joint hearing or trial of any or all the matters in issue in the actions; it may order all the actions consolidated; and it may make such orders concerning proceedings therein as may tend to avoid unnecessary costs or delay. This means that if there are multiple lawsuits with the same or similar parties and issues pending in Kansas courts, a judge has the discretion to consolidate these cases to streamline the process and reduce redundancy. The decision to consolidate is typically based on the judge's determination that consolidation would be more efficient and just for all parties involved. If the cases are in different courts within the state, a transfer may be ordered to bring them into the same court for consolidation. Federal courts have a similar rule under Federal Rule of Civil Procedure 42(a), which allows for consolidation when cases involve common questions of law or fact. The decision to consolidate is at the discretion of the court and is intended to promote judicial efficiency and reduce the burden on the parties and the court system.