How Popes Are Chosen
Exerpted from Catholic Update
, The Future of the Papacy
When the pope dies, the cardinals are summoned to Rome by the dean of the college of cardinals for the conclave that will elect the new pope.
The word conclave (Latin, cum + clavis, literally, "locked with the key") designates the place in a locked section of the Vatican where the cardinals remain until a new pope is elected. It is also used to designate the actual gathering of the cardinals.
Before the conclave: The cardinals may discuss the upcoming election with one another. The conclave begins 15 to 20 days after the pope's death.
The actual conclave: After the celebration of Mass, the cardinal dean presides over the preliminary sessions, where procedures regulated by canon law are clarified. Then all others are dismissed and the cardinals are sealed in the Sistine Chapel where the voting takes place, every morning and afternoon.
Until recently a two-thirds majority plus one was required for election. After his election Pope John Paul II changed this. Now if there is no conclusive vote after 30 ballots, an absolute majority suffices. [This means that if a candidate gets a majority on the first or second ballot, his supporters need only wait till 30 ballots have been cast. He will then be elected on the 31st ballot.]
For each ballot, the cardinals are given rectangular cards with Eligo in summum pontificem ("I elect as supreme pontiff") printed at the top. Each cardinal prints the name of his choice. One by one in order of seniority they approach the altar where there is a chalice with a paten on top. They place the ballot (folded down the middle) on the paten, then drop it into the cup.
After each voting the ballots are burned. Special chemicals are added to make the smoke white or black. To people eagerly waiting outside, black smoke signifies an inconclusive vote. White smoke announces that a pope has been elected.
The cardinals may elect whomever they wish, as long as the person is a baptized male. There have been occasions in the past when laymen were elected. After their election they had to be ordained priest and bishop. The one elected is asked if he accepts. The moment he accepts he is pope and, if he is a bishop, he is Bishop of Rome. If he is not a bishop he is immediately ordained by the dean of the college. The cardinals individually pledge their support to the new pope. The cardinal dean asks the pope what name he chooses. Then the oldest member of the college announces the choice to the city of Rome and to the world.