You must complete discovery 30 days before your trial. Discovery is how you gather the evidence you will need to prove your case as plaintiff, or defeat the plaintiff's case as a defendant.This guide contains forms and instructions for scheduling a deposition of an opposing party or third party witness in a California civil case. This guide contains forms and instructions for responding to Requests for Production from your opponent in a California civil case. Lawyer guide on motions to compel in Sacramento, California. This guide covers motions to compel interrogatories, document requests, and admissions. For instance, in the Northern District of California you must move to compel within seven days of the close of discovery. For a non-party witness written notice is required.