Illinois Summons In a Civil Action is a legal document used to initiate a lawsuit in the state of Illinois. It is served by the court clerk or an authorized process server on the defendant or respondent, informing them of the lawsuit and the court dates. The Summons will also list the plaintiff or petitioner's claims and the relief they are seeking. There are two types of Illinois Summons In a Civil Action: the Summons for Service by Publication and the Summons for Personal Service. The Summons for Service by Publication is used when the defendant or respondent cannot be located or served directly. The Summons for Personal Service is used when the defendant can be located and served directly.