The Supreme Court consists of the Chief Justice of California and 6 associate justices. The Chief Justice may convene the court at any time. Concurrence of 4 judges present at the argument is necessary for a judgment.
An acting Chief Justice shall perform all functions of the Chief Justice when the Chief Justice is absent or unable to act. The Chief Justice or, if the Chief Justice fails to do so, the court shall select an associate justice as acting Chief Justice.
Cal. Const. art. VI § 2