The Rite of Succession is a Klingon ritual which must be performed by a prospective candidate in order to be considered for leadership of the Empire. Performed upon the death of the previous leader, the Rite is overseen by the Arbiter of Succession. The ritual is preceded by the elaborate Sonchi ceremony, which verifies the death of the previous leader. In 2367, Chancellor K'mpec took the unorthodox step of naming Captain Jean-Luc Picard as the Arbiter after his death, since no Klingon could be trusted.
In modern times, the Rite of Succession consists merely of a proclamation that the challengers have been chosen. In ancient times, the Rite was a long, involved affair where each prospective candidate must perform the ja'chuq to prove their worthiness to lead the Empire. Picard chose to revive this rite as a delay tactic while investigating an assassination attempt on K'mpec's ship. (TNG: "Reunion")