Collusive litigation occurs when the plaintiff and defendant in a lawsuit aren't truly adverse. Instead of fighting over a real dispute, both sides work together to produce a predetermined result, often a court order or settlement that neither party actually opposes. Federal courts require genuine adversity between parties under Article III of the Constitution. When a president sues agencies under his own control, courts must examine whether the lawsuit is collusive because the executive branch effectively controls both sides. Judges can dismiss such cases for lack of standing or reject settlements that don't serve the public interest.