What is Business Judgment Rule?

Legal Definition
The business judgment rule is a case law-derived doctrine in corporations law that courts defer to the business judgment of corporate executives. It is rooted in the principle that the "directors of a corporation... are clothed with [the] presumption, which the law accords to them, of being [motivated] in their conduct by a bona fide regard for the interests of the corporation whose affairs the stockholders have committed to their charge". The rule exists in some form in most common law countries, including the United States, Canada, England and Wales, and Australia.

To challenge the actions of a corporation's board of directors, a plaintiff assumes "the burden of providing evidence that directors, in reaching their challenged decision, breached any one of the triads of their fiduciary duty — good faith, loyalty, or due care". Failing to do so, a plaintiff "is not entitled to any remedy unless the transaction constitutes waste... [that is,] the exchange was so one-sided that no business person of ordinary, sound judgment could conclude that the corporation has received adequate consideration".
-- Wikipedia
Legal Definition
In suits alleging a corporation's director violated his duty of care to the company, courts will evaluate the case based on the business judgment rule. Under this standard, a court will not second guess the decisions of a director as long as they are made (1) in good faith, (2) with the care that a reasonably prudent person would use, and (3) with the reasonable belief that they are acting in the best interests of the corporation.
Legal Definition
Standard for imposing liability on directors of corporation; they must give time and thought to decisions.