The defendant in a lawsuit must be served (delivered) a summons or citation (an order from the court to appear and answer the lawsuit) and a copy of the lawsuit (the complaint) (1) to provide due process (fairness) by giving the defendant notice of the lawsuit and the opportunity to appear in court and defend the lawsuit; and (2) to give the court personal jurisdiction (authority) over the defendant.
In Ohio, as in all states, the legal process requires that a defendant in a lawsuit must be properly served with a summons or citation and a copy of the complaint initiating the lawsuit. This is to ensure due process, which is the constitutional right to be informed of legal action against oneself and to have a fair opportunity to respond and defend against the lawsuit in court. Service of process must be carried out in a manner prescribed by law, which typically includes personal delivery to the defendant, delivery to someone of suitable age and discretion at the defendant's residence, or by certified mail. Additionally, service of process gives the court personal jurisdiction over the defendant, meaning the court has the authority to make decisions regarding the defendant in the context of the case. Failure to properly serve a defendant can result in delays or dismissal of the lawsuit. Ohio's rules regarding service of process are detailed in the Ohio Rules of Civil Procedure, specifically Rule 4.