It is against public policy for any oil or gas lease, at its inception, to provide for the waiver of any rights created by this article, or for such rights to be waived by amendment to any oil or gas lease within 20 years of the date of its execution by a plaintiff or the plaintiff’s predecessor in interest.
Source:
Section 772.060, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=CCP§ionNum=772.060..