What is the law of the case doctrine and what is the effect of the law-of-the case doctrine?

The law of the case doctrine provides that " '[w]here an appellate court states a rule of law necessary to its decision, such rule " 'must be adhered to' " in any " 'subsequent appeal' " in the same case, even where the former decision appears to be " 'erroneous.' " ' [Citations.] Thus, the law-of-the-case doctrine 'prevents the parties from seeking appellate reconsideration of an already decided issue in the same case absent some significant change in circumstances.' " (People v. Boyer (2006) 38 Cal.4th 412, 441.) The doctrine, however, "is one of procedure, not jurisdiction, and it will not be applied 'where its application will result in an unjust decision, e.g., where there has been a "manifest misapplication of existing principles resulting in substantial injustice." ' " (Ibid.)