Supreme Court of the United States
The Supreme Court chooses which cases it will decide on, by choosing to give a writ of certiorari or not. Almost 7,000 people, known as petitioners, ask the Supreme Court to decide their cases every year, but the court only gives a writ to about 100 or less. For the Supreme Court to decide a case, the case must be about: federal law, the Constitution of the United States, disagreements between states or their residents, or another court's decision that differs from what the Supreme Court has decided on a similar case. Cases must first be decided by a federal district court and a federal court of appeals or by a state supreme court. Even after that, the Supreme Court can choose not to decide a case for any reason. Cases about disagreements between states or their residents sometimes can only be decided by the Supreme Court, but those are rare.