A corporation may exercise two types of powers: (1) express powers, set forth by statute and in the articles of incorporation, and (2) implied powers, necessary to carry out its stated purpose. The corporation may always amend the articles of incorporation to change its purposes. Nevertheless, shareholders may enjoin their corporation from acting ultra vires, as may the state attorney general. However, an individual stockholder, director, or officer (except in rare instances under certain regulatory statutes) may not be held vicariously liable if he did not participate in the crime or tort.

Because ownership and control are separated in the modern publicly held corporation, shareholders generally do not make business decisions. Shareholders who own voting stock do retain the power to elect directors, amend the bylaws, ratify or reject certain corporate actions, and vote on certain extraordinary matters, such as whether to amend the articles of incorporation, merge, or liquidate.

In voting for directors, various voting methodologies may be used, such as cumulative voting, which provides safeguards against removal of minority-shareholder-supported directors. Shareholders may use several voting arrangements that concentrate power, including proxies, voting agreements, and voting trusts. Proxies are regulated under rules promulgated by the Securities and Exchange Commission (SEC).

Corporations may deny preemptive rights—the rights of shareholders to prevent dilution of their percentage of ownership—by so stating in the articles of incorporation. Some states say that in the absence of such a provision, shareholders do have preemptive rights; others say that there are no preemptive rights unless the articles specifically include them.

Directors have the ultimate authority to run the corporation and are fiduciaries of the firm. In large corporations, directors delegate day-to-day management to salaried officers, whom they may fire, in most states, without cause. The full board of directors may, by majority, vote to delegate its authority to committees.

Directors owe the company a duty of loyalty and of care. A contract between a director and the company is voidable unless fair to the corporation or unless all details have been disclosed and the disinterested directors or shareholders have approved. Any director or officer is obligated to inform fellow directors of any corporate opportunity that affects the company and may not act personally on it unless he has received approval. The duty of care is the obligation to act “with the care an ordinarily prudent person in a like position would exercise under similar circumstances.” Other fiduciary duties have also been recognized, and constituency statutes permit the corporation to consider factors other than shareholders in making decisions. Shareholders may file derivative suits alleging breaches of fiduciary responsibilities. The duties have been expanded. For example, when the corporation is being sold, the directors have a duty to maximize shareholder value. Duties of oversight, good faith, and candor have been applied.

The corporation may agree, although not in every situation, to indemnify officers, directors, and employees for litigation expenses when they are made party to suits involving the corporation. The corporation may purchase insurance against legal expenses of directors and officers, but the policies do not cover acts of willful negligence and criminal conduct in which intent is a necessary element of proof. Additionally, the business judgment rule may operate to protect the decisions of the board.

The general rule is to maximize shareholder value, but over time, corporations have been permitted to consider other factors in decision making. Constituency statutes, for example, allow the board to consider factors other than maximizing shareholder value. Corporate social responsibility has increased, as firms consider things such as environmental impact and consumer perception in making decisions.