San Francisco enacted instant runoff voting in 2002, and uses the name ranked choice voting. San Francisco's first election with ranked choice voting was in 2004 and it has been used annually since then. San Francisco's charter governing ranked choice voting elections is shown below.
SEC. 13.102. - INSTANT RUNOFF ELECTIONS.
(a) For the purposes of this section: (1) a candidate shall be deemed "continuing" if the candidate has not been eliminated; (2) a ballot shall be deemed "continuing" if it is not exhausted; and (3) a ballot shall be deemed "exhausted," and not counted in further stages of the tabulation, if all of the choices have been eliminated or there are no more choices indicated on the ballot. If a ranked-choice ballot gives equal rank to two or more candidates, the ballot shall be declared exhausted when such multiple rankings are reached. If a voter casts a ranked-choice ballot but skips a rank, the voter's vote shall be transferred to that voter's next ranked choice.
(b) The Mayor, Sheriff, District Attorney, City Attorney, Treasurer, Assessor-Recorder, Public Defender, and members of the Board of Supervisors shall be elected using a ranked-choice, or "instant runoff," ballot. The ballot shall allow voters to rank a number of choices in order of preference equal to the total number of candidates for each office; provided, however, if the voting system, vote tabulation system or similar or related equipment used by the City and County cannot feasibly accommodate choices equal to the total number of candidates running for each office, then the Director of Elections may limit the number of choices a voter may rank to no fewer than three. The ballot shall in no way interfere with a voter's ability to cast a vote for a write-in candidate.
(c) If a candidate receives a majority of the first choices, that candidate shall be declared elected. If no candidate receives a majority, the candidate who received the fewest first choices shall be eliminated and each vote cast for that candidate shall be transferred to the next ranked candidate on that voter's ballot. If, after this transfer of votes, any candidate has a majority of the votes from the continuing ballots, that candidate shall be declared elected.
(d) If no candidate receives a majority of votes from the continuing ballots after a candidate has been eliminated and his or her votes have been transferred to the next-ranked candidate, the continuing candidate with the fewest votes from the continuing ballots shall be eliminated. All votes cast for that candidate shall be transferred to the next-ranked continuing candidate on each voter's ballot. This process of eliminating candidates and transferring their votes to the next-ranked continuing candidates shall be repeated until a candidate receives a majority of the votes from the continuing ballots.
(e) If the total number of votes of the two or more candidates credited with the lowest number of votes is less than the number of votes credited to the candidate with the next highest number of votes, those candidates with the lowest number of votes shall be eliminated simultaneously and their votes transferred to the next-ranked continuing candidate on each ballot in a single counting operation.
(f) A tie between two or more candidates shall be resolved in accordance with State law.
(g) The Department of Elections shall conduct a voter education campaign to familiarize voters with the ranked-choice or, "instant runoff," method of voting.
(h) Any voting system, vote tabulation system, or similar or related equipment acquired by the City and County shall have the capability to accommodate this system of ranked-choice, or "instant runoff," balloting.
(i) Ranked choice, or "instant runoff," balloting shall be used for the general municipal election in November 2002 and all subsequent elections. If the Director of Elections certifies to the Board of Supervisors and the Mayor no later than July 1, 2002 that the Department will not be ready to implement ranked-choice balloting in November 2002, then the City shall begin using ranked-choice, or "instant runoff," balloting at the November 2003 general municipal election.
If ranked-choice, or "instant runoff," balloting is not used in November of 2002, and no candidate for any elective office of the City and County, except the Board of Education and the Governing Board of the Community College District, receives a majority of the votes cast at an election for such office, the two candidates receiving the most votes shall qualify to have their names placed on the ballot for a runoff election held on the second Tuesday in December of 2002.