Saudi Arabia's king has issued a decree detailing the implementation of a succession law announced a year ago.
Succession of oil-rich Saudi Arabia's absolute rulers has global impact
The decree outlines the workings of a committee to choose future Saudi kings and the crown princes.
It stipulates committee members must be male heirs of the kingdom's founder, Abdul Aziz bin Saud.
Correspondents say the measures are designed to smooth the transition of power and prevent leadership disputes which have erupted in the past.
Under the new regulations, the so-called Allegiance Commission is to meet immediately after the death of a monarch to name the crown prince as king.
The new ruler would then have 10 days to inform the commission of his choice of crown prince.
Previously, the succession has been decided by informal consensus within the Saudi family, but the secrecy and lack of clarity about the process has generated rumours bitter power struggles, for example during the long illness of the late King Fahd.
The current monarch, King Abdullah, 83, is the fifth son of Abdul Aziz to be absolute ruler of Saudi Arabia, which is the world's biggest petroleum producer.
He named his half-brother, Prince Sultan, 82, as crown prince when he succeeded Fahd in 2005, but there is speculation that after Sultan the succession may pass to the next generation.