Each modern constitution provides for a 'head of state' through election, appointment or descent. Traditional and neo-traditional monarchies, executive presidents and ceremonial presidents are all present in the Asia Pacific. Although the office is generally described as being either an executive one, as in Indonesia and the Philippines, or a ceremonial one, as in Japan and Papua New Guinea and other Pacific nations, the powers of yet other heads of state are far-reaching, even if rarely used. There are also states in which the nominal head of state is represented by another constitutional figure, such as a governor (or governor-general). In general terms, the most problematic issues in relation to the role and powers of the head of state have been determining methods for selection, conditions for removal, length of term, and extent of powers allocated.

Most heads of state are elected by an electoral college or by the parliament, in indirect elections. Countries having direct presidential elections include Singapore, Taiwan and Palau. The model in a particular country will set the pattern for many of the functions and powers of the office. The head of state has mostly created controversy by dismissing governments and judicial figures, and by invoking and/or revoking the use of emergency powers. In moments of constitutional crisis, the head of state has at times been positioned between the will of an elected government and the will of other sources of power, such as the military.