Law of the case provides that a court’s decision on an issue governs subsequent stages of the same case. It is a discretionary doctrine of practice, not a jurisdictional limit.
Between trial court rulings. A judge may revisit an interlocutory ruling before final judgment, and successor judges are generally reluctant to disturb a predecessor’s decisions without good reason.
After appellate decision. Here the doctrine hardens into the mandate rule: the trial court on remand must implement both the letter and the spirit of the mandate and may not reconsider issues decided expressly or by necessary implication.
Scope of remand. A general remand permits the trial court to address matters not decided; a limited remand confines it to the specified task. Which was issued is a frequent dispute, and appellate courts increasingly state the scope explicitly.
Exceptions. Intervening controlling authority; substantially different evidence on remand; and a prior decision that was clearly erroneous and would work manifest injustice.
Waiver by omission. Issues that could have been raised in the first appeal but were not are generally treated as forfeited in a later one, which is a significant reason not to hold arguments back.
Practical use. On remand, the first submission should state precisely what the mandate decided and what it left open, because that framing tends to determine the scope of the proceedings that follow.