An order, line or right of succession is the line of individuals necessitated to hold a high office when it becomes vacated, such as head of state or an honour such as a title of nobility.[1] This sequence may be regulated through descent or by statute.[1]
Hereditary government form differs from elected government. An established order of succession is the normal way of passing on hereditary positions, and also provides immediate continuity after an unexpected vacancy in cases where office-holders are chosen by election: the office does not have to remain vacant until a successor is elected. In some cases the successor takes up the full role of the previous office-holder, as in the case of the presidency of many countries; in other non-hereditary cases there is not a full succession, but a caretaker chosen by succession criteria assumes some or all of the responsibilities, but not the formal office, of the position. For example, when the position of President of India becomes vacant, the Vice-President of India temporarily carries out the functions of the presidency until a successor is elected; in contrast, when the position of President of the Philippines is vacant, the Vice-President of the Philippines outright assumes the presidency itself for the rest of the term.
Organizations without hereditary or statutory order of succession require succession planning if power struggles prompted by power vacuums are to be avoided.