An Illinois Subpoena-Deposition is a legal document issued by a court in the state of Illinois during a civil or criminal trial. This document requires an individual to appear in court and give testimony under oath. Generally, a Subpoena-Deposition requires the individual to answer questions posed by either the plaintiff or defendant, or both parties. There are three types of Illinois Subpoenas-Depositions: 1) Subpoena Ducks Cecum, which requires the individual to produce documents and other tangible items; 2) Subpoena Ad Testificandum, which requires the individual to testify in court; and 3) Subpoena Ad Testimonial, which requires the individual to provide sworn written answers to questions posed by either the plaintiff or defendant. All three types of Illinois Subpoena-Depositions can be issued by the court in order to obtain evidence and testimony during a civil or criminal trial.