Prerogative
A prerogative was a special right or power that was given to a person or group by a government or state. Starfleet captains often had the prerogative to do something by virtue of their rank.
In 2367, while standing in the observation lounge, Jean-Luc Picard said, "It is my prerogative to investigate anything that may be relevant to the Rite of Succession." (TNG: "Reunion")