Monarchy, where the divine right of kings establishes the political legitimacy of the rule of the monarch (king or queen); legitimacy also derives from the popular perception (tradition and custom) and acceptance of the monarch as the rightful ruler of nation and country. Contemporarily, such divine-right legitimacy is manifest in the absolute monarchy of the House of Saud (est. 1744), a royal family who have ruled and governed Saudi Arabia since the 18th century. Moreover, constitutional monarchy is a variant form of monarchic political legitimacy which combines traditional authority and legal–rational authority, by which means the monarch maintains nationalist unity (one people) and democratic administration (a political constitution)

In political science, legitimacy is the right and acceptance of an authority, usually a governing law or a regime. Whereas authority denotes a specific position in an established government, the term legitimacy denotes a system of government—wherein government denotes "sphere of influence"

In rational choice theory, human individuals or groups can be modelled as 'actors' who choose from a 'choice set' of possible actions in order to try to achieve desired outcomes. An actor's 'incentive structure' comprises (its beliefs about) the costs associated with different actions in the choice set, and the likelihoods that different actions will lead to desired outcomes. In this setting we can differentiate between: outcome power – the ability of an actor to bring about or help bring about outcomes; social power – the ability of an actor to change the incentive structures of other actors in order to bring about outcomes. This framework can be used to model a wide range of social interactions where actors have the ability to exert power over others. For example, a 'powerful' actor can take options away from another's choice set; can change the relative costs of actions; can change the likelihood that a given action will lead to a given outcome; or might simply change the other's beliefs about its incentive structure.

Rational choice theory refers to a set of guidelines that help understand economic and social behaviour.[1] The theory originated in the eighteenth century and can be traced back to political economist and philosopher, Adam Smith.[2] The theory postulates that an individual will perform a cost-benefit analysis to determine whether an option is right for them.[3] It also suggests that an individual's self-driven rational actions will help better the overall economy. Rational choice theory looks at three concepts: rational actors, self interest and the invisible hand.