California Code, Code of Civil Procedure - CCP § 872.540

Where property is subject to a lease, community lease, unit agreement, or other pooling arrangement with respect to oil or gas or both, the plaintiff need not join as defendants persons whose only interest in the property is that of a lessee, royalty-owner, lessor-owner of other real property in the community, unit, or pooled area, or working interest owner, or persons claiming under them, and the judgment shall not affect the interests of such persons not joined as defendants.