The business judgment rule is the default lens courts use to review decisions made by a corporation's board of directors. It presumes directors are better positioned than judges to weigh business risk, so as long as a decision was informed, made in good faith, and free of a disqualifying financial conflict, a court will not second-guess it just because it turned out badly. The presumption protects the decision-making process, not the outcome.

The presumption is rebuttable. A plaintiff who pleads specific facts showing a director was uninformed, acted in bad faith, or stood on both sides of the transaction can knock the presumption out. Once that happens, the burden shifts to the defendant director to justify the decision under a tougher standard, often entire fairness. Whether a case stays under business-judgment deference or moves to heightened review is frequently the whole ballgame in a derivative suit or a challenge to a merger, a rights plan, or executive compensation.

Because the rule turns on a handful of provable facts — was the board informed, was there a conflict, was the process rushed — it functions as a threshold gate rather than a merits verdict. Juricratic models that gate as a branch point: a matter can be simulated under business-judgment deference and, separately, under a rebutted-presumption track where entire fairness applies, so a user can see how much the standard of review alone moves the case's projected trajectory before any fact about the underlying decision changes.

Defense counsel invokes the business judgment rule early, usually on a motion to dismiss, to end a derivative suit before discovery. Plaintiffs respond by pleading particularized facts about process failures or conflicts to try to rebut the presumption and force the case into discovery or an entire fairness posture. Boards also rely on the rule prospectively, building a documented, deliberate process before a contested decision specifically so it will hold up under this standard later.