The Quorum of the Twelve Apostles is the second presiding body of the Church of Jesus Christ of Latter-day Saints. Its twelve members are ordained for life and ranked strictly by the date of their ordination, which makes the line of succession to the presidency of the church visible years ahead. It meets weekly with the First Presidency in a room in the Salt Lake Temple, and when a president of the church dies it becomes the governing body of the movement outright until a new president is ordained.
Its published rule of decision is the feature outsiders find most surprising: the quorum acts only by unanimity. A matter on which the members do not all agree is not carried by a majority; it is deferred, sometimes for years, until either agreement is reached or the question lapses. The rule is stated in the church's own handbook and has been described publicly by apostles. It explains a great deal about the pace at which the church changes, and about why announcements, when they come, arrive without any public record of disagreement beforehand.
The quorum supervises the areas into which the church divides the world, calls and ordains general officers and stake presidents, dedicates temples, and sits on the boards governing the church's finances, universities and welfare system. Its members are sustained by the whole church as prophets, seers and revelators alongside the First Presidency.