Venue refers to the county in which the suit is filed. The purpose behind these rules is to provide some control to a defendant over where the matter is litigated, so as to make it less difficult or less impractical for the party to mount its defense. The determination of where venue is proper starts with a consideration of the main relief sought in the matter.
If the main relief sought involves rights to real property, the action is considered “local” and venue is usually only appropriate in the county in which such real property is located. Common types of these cases include unlawful detainer actions and injuries to real property like trespass or damage to buildings on the land. According to Code of Civil Procedure, Section 392(a)(1), if the real property extends into two or more counties, venue is proper in either of those counties.
If the main relief sought is personal in nature, such as pain and suffering or physical injuries, then the action is considered “transitory”, and the general standard calls for the action to be heard in the area in which the defendant resides. “Except as otherwise provided by law and subject to the power of the court to transfer … the county where the defendants or some of them reside at the commencement of the action is the proper court for the trial of the action.” Code of Civil Procedure, Section 395(a); see Brown v. Sup.Ct. (C.C. Myers, Inc.) (1984) 37 Cal. 3d 477, 483.
As you can see, sometimes several venues are appropriate at the time the original complaint is filed. Proper motion to the Court can result in transfer of the case to a proper venue, and the attorney choosing the improper venue can be ordered to pay sanctions to the moving party. According to Code of Civil Procedure, Section 396b(b), those “expenses and fees shall be the personal liability of the attorney not chargeable to the party.”