Grade-taking is a term used in anthropology for social systems under which individuals rise in status and authority by performing a series of ceremonies.
Grade-taking was the system of leadership in pre-colonial societies of northern Vanuatu, typically involving the killing of valuable pigs; it is still actively practiced in some areas.
The concept of a "chief" - an individual with specific authority over a community, rather than a ranked assortment of men with varying degrees of power and influence, was introduced to northern Vanuatu following contact with Europeans.
In North and Central Pentecost, the titles of the main grades are Tari, Mol or Moli, Liwus or Livusi, and Vii or Vira.
In Central Pentecost those who reach the very top level of the graded society are referred to as Tanmwonok (literally "ground finishing"); those who do so with resources still to spare are known as Mwariak ("remaining").