The late Pope John Paul II set out a series of guidelines to ensure the centuries-old secret deliberations for electing a new pontiff would be safe in the age of media leaks and cell phones.
Traditionally, electors have been literally locked up inside the Apostolic Palace until they chose a new leader for the Roman Catholic Church. But in a change made in 1996, John Paul declared the cardinals would be housed within a hotel and free to roam inside the Vatican walls.
They are, however, forbidden from communicating with the outside world, and cell phones and computers have been banned. Vatican officials say the Sistine Chapel and other areas will be inspected for electronic devices, and anyone violating the rules will be subject to "grave penalties" including excommunication.
The 117 eligible cardinals will start the conclave on April 18. During the deliberations, they will vote four times a day, twice each in the morning and evening. When they succeed in electing a new pope, white smoke will rise from a chimney above the Sistine Chapel and the bells of Saint Peter's will begin tolling.
The new pontiff will then step out onto the central balcony overlooking Saint Peter's Square to give the thousands gathered below and the world his first blessing.
Some information for this story provided by AP and Reuters.