This is a how-to guide on interrogatories and requests for production in Washington divorce and family law cases. Interrogatories are a set of written questions that one side in a lawsuit sends to the other side to gather information and evidence.These interrogatories are intended to provide for the exchange of relevant information without unreasonable expense to the answering party. FILING AND SERVICE. Service. Interrogatories must be served on the party from whom responses are sought and all other parties who have appeared in the action. In accordance with Washington. Superior Court Rules 26 and 33, please answer each of the following interrogatories separately, fully, in writing and under oath. In accordance with Washington. Superior Court Rules 26 and 33, please answer each of the following interrogatories separately, fully, in writing and under oath. Have a friend who is not a party to the case serve the discovery.