Voting
On the afternoon of the first day, one ballot (referred to as a "scrutiny") may be held, but is not required. A maximum of four ballots are held on each successive day: two in each morning and two in each afternoon. Before voting in the morning and again before voting in the afternoon, the electors take an oath to obey the rules of the conclave.
If no result is obtained after three vote days of balloting, the process is suspended for a maximum of one day for prayer and an address by the senior cardinal deacon. After seven further ballots, the process may again be similarly suspended, with the address now being delivered by the senior cardinal priest. If, after another seven ballots, no result is achieved, voting is suspended once more, the address being delivered by the senior cardinal bishop.
After a further seven ballots, there shall be a day of prayer, reflection and dialogue. In the following ballots, only the two names who received the most votes in the last ballot shall be eligible in a runoff election where a two-thirds majority is still required. The two people voted on, even if cardinal electors, shall not themselves have the right to vote.
The process of voting consist of three phases: the "pre-scrutiny", the "scrutiny", and the "post-scrutiny".
During the pre-scrutiny, the masters of ceremonies prepare ballot papers bearing the words Eligo in Summum Pontificem ('I elect as Supreme Pontiff') and provide at least two to each cardinal elector. As the cardinals begin to write their votes, the secretary of the College of Cardinals, the master of papal liturgical celebrations and the masters of ceremonies exit. The junior cardinal deacon then closes the door.
During the first pre-scrutiny of any given morning, the junior cardinal deacon randomly draws nine names. The first three cardinals so chosen become scrutineers, the second three infirmarii and the last three revisers. These cardinals retain their roles for the second scrutiny of the morning, if it is needed.
If both morning scrutinies fail to produce a result, the cardinals re-take the oath to obey the rules of the conclave once they have eaten lunch and again gathered in the Sistine Chapel. A drawing is held to choose new scrutineers, infirmarii, and revisers, and the third scrutiny of the day is then held, immediately followed by a fourth if necessary.
No changes in these rules were made by Benedict XVI in 2007. These were the rules followed so far as is known, given the secrecy of the conclave in electing Leo XIV in May 2025.
In order of precedence, the cardinals approach the scrutineers at the altar and deposit their ballots into a receptacle there. Each ballot bears only the name of the candidate selected by its holder, who recites the following Latin oath before casting it:
If any cardinal elector is in the chapel, but cannot proceed to the altar due to infirmity, the last scrutineer may go to him and take his ballot after he has recited the oath. If any cardinal electors are confined to their rooms for this reason, the infirmarii go to their rooms with ballot papers and a box. These cardinals fill out their ballots, recite the oath, and place them in the box. When the infirmarii return to the chapel, the ballots are counted to ensure that their number matches with the number of ill cardinals, whereupon they are transferred to the receptacle holding the ballots cast by those in the chapel.
If no candidate receives a two-thirds vote on the first scrutiny, then a second scrutiny immediately follows. A maximum of four scrutinies can be carried out per day, two apiece in the morning and afternoon.
Under present rules, the oath that cardinals take when casting their votes is only verbal, since they no longer sign their names on the ballots. Previous rules required each cardinal to sign his ballot and mark it with a unique identification code, or motif. He then folded the ballot in two places to cover his signature and motif, leaving only the name of his chosen candidate exposed, and sealed it with wax to create a semi-secret ballot.
The wax seals were opened only if a candidate received the bare minimum needed for election. This was to ensure that the apparently elected man had not voted for himself. This was the procedure from 1621 to 1945. The example above is a copy of the three section semi-secret ballot, which was last used in the conclave of 1939. There was no oath taken when actually casting ballots, prior to 1621.
Semi-secret ballots with initials or motif written on the back of the ballot, or voting verbally, at the option of the cardinals present and voting, were sometimes used prior to 1621. These secret ballots had no oath taken when the vote was actually cast. At some conclaves prior to 1621, the cardinals verbally voted and sometimes stood in groups to facilitate counting the votes cast. The signature and motif of the elector covered by two folded-over parts of the ballot paper was added by Gregory XV in 1621, to prevent anyone from casting the deciding vote for himself, and also to insure semi-secrecy.
In 1549, Cardinal Pole of England refused to cast the deciding vote for himself, which would then have been followed by the accession to raise his vote total to at least one more than the minimum number needed, and was not elected. In 1492, Cardinal Borgia (Pope Alexander VI) almost certainly privately bribed other cardinals to vote for him. It is certain that he would not have been allowed to cast the deciding vote for himself, without the knowledge and consent of the other cardinals. A procedure called accession gave electors who had not voted for the possible new pope the opportunity to change their votes and make the election unanimous, or nearly so, (except for the vote of the possible new pope). This is how Cardinal Borgia was elected pope in 1492. To make accession work, each elector had to sign or code his ballot to later identify it, if he desired to change his vote to a different candidate.
Faced by the mortal challenge to the papacy emanating from Protestantism, and fearing schism due to several stormy conclaves in the late 16th and early 17th centuries, Gregory XV established the procedure of signed ballots with covering fold over flaps sealed with wax to prevent any cardinal from casting the deciding vote for himself. The accession was not ended, but was seldom used until Pius XII abolished it in 1945. Since 1945, a cardinal can cast the deciding vote for himself without the accession, though the two-thirds majority rule has always been continued, except when John Paul II had modified that rule in 1996, after 33 ballots, a simple majority being sufficient. The two-thirds majority rule was restored in 2007 by Benedict XVI.
Prior to 1621, the only oath taken was that of obedience to the rules of the conclave in force at that time, when the cardinals entered the conclave and the doors were locked, and each morning and afternoon as they entered the Sistine Chapel to vote. Gregory XV added the additional oath, taken when each cardinal casts his ballot, to prevent cardinals wasting time in casting "courtesy votes" and instead narrowing the number of realistic candidates for the papal throne to perhaps only two or three. Speed in electing a pope was important, and that meant using an oath so as to get the cardinals down to the serious business of electing a new pope and narrowing the number of potentially electable candidates.
The reforms of Gregory XV in 1621 and reaffirmed in 1622 created the written detailed step-by-step procedure used in choosing a pope; a procedure that was essentially the same as the process used in 2025 to elect Pope Leo XIV. The biggest change since 1621 was the elimination of the rule that required the electors to sign their ballots, resulting in the detailed voting procedure of scrutiny making use of simple verbal oaths. Beginning in 1945, an elector could vote for himself and then call on God via the oath taken when the vote is dropped into the receptacle, to declare himself to be the best one qualified for the papacy. The use of the accession would prevent this, but is not allowed under the present rules. Beginning with the use of totally secret ballots in the 1958 conclave, it is now possible for a cardinal to cast the deciding vote for himself, without the knowledge and consent of the other cardinals.
Once all votes have been cast, the first scrutineer chosen shakes the container, and the last scrutineer removes and counts the ballots. If the number of ballots does not correspond to the number of cardinal electors present, including sick cardinals in their rooms, the ballots are burnt, unread, and the vote is repeated. If no irregularities are observed, the ballots may be opened and the votes counted. Each ballot is unfolded by the first scrutineer. All three scrutineers separately write down the name indicated on the ballot. The last of the scrutineers reads the name aloud.
Once all of the ballots have been opened, the final post-scrutiny phase begins.
The scrutineers add up all of the votes, and the revisers check the ballots and the names on the scrutineers' lists to ensure that no error has been made. The ballots are then stitched together with a needle and red thread and burned by the scrutineers with the assistance of the secretary of the College of Cardinals and the masters of ceremonies. If the first scrutiny held in any given morning or afternoon does not result in an election, the cardinals proceed to the next scrutiny immediately. The papers from both scrutinies are then burned together at the end of the second scrutiny.
Beginning in the early 1800s, the ballots used by cardinals were burned after each ballot to indicate a failed election. The lack of smoke instead signalled a successful election. Since 1914, black smoke (fumata nera) emerging from a temporary chimney installed on the roof of the Sistine Chapel indicates that the ballot did not result in an election. White smoke (fumata bianca) announces that a new pope has been chosen. Smoke is not necessarily issued after every unsuccessful election; when there has been two votes, the ballots from the two votes are burned together.
Until 1945, when Pius XII changed the form of ballot to use the unsigned ballots first used in 1958, the sealing wax on the complex type ballots illustrated above had the effect of making the smoke from burning the ballots either black or white, depending on whether or not damp straw was added. Until the 20th century, sealing wax customarily had beeswax mixed into its composition. Burning wax made solely from animal fat does not give as much white smoke as does wax that includes beeswax.
In the 1939 conclave, there was some confusion over the smoke color, which was even more apparent in the 1958 conclave. The lack of sealing wax on the ballots likely explains the confusion over the color of the smoke in the 1958 conclave. The Siri thesis was based on the confusion over the smoke color on the first day of that conclave.
Since 1963 chemicals have been added to the burning process to augment the smoke's black or white color. Since 2005, a successful election has been announced by the bells of Saint Peter's Basilica ringing at the appearance of the white smoke.
During the 2013 conclave, the Vatican disclosed the chemicals used. The black smoke is made by adding potassium perchlorate, anthracene, and sulfur. The white smoke is made by adding potassium chlorate, lactose, and pine rosin. Sugar is burned to produce large amounts of gaseous output, primarily water vapor (steam) and carbon dioxide. Pine rosin produces a "thick white smoke" when heated and contains terpenes, which burn to yield a pale, visible smoke.
