The following words and terms when used in this chapter shall have the following meanings unless the context clearly indicates otherwise:

"Active ballot" means a ballot that counts toward an active candidate in the current round of counting.

"Active candidate" means a candidate or person who has not been defeated during a round-by-round vote count. In a count that lasts multiple rounds, the number of active candidates will decrease with each round.

"Batch elimination" means the simultaneous defeat of multiple candidates for whom it is mathematically impossible to be elected.

"Duplicate ranking" means a voter has assigned one candidate multiple rankings.

"Election threshold" means the number of votes sufficient for a candidate to be elected in a multi-winner, single transferable vote contest, except in the first-choice ranking tabulation round. The election threshold equals the total valid votes cast for active candidates in the first round of tabulation, pursuant to 1VAC20-100-50 C, divided by the sum of one plus the number of offices to be filled, then adding one, disregarding any fractions. Election threshold = ((Total valid votes cast for active candidates in the first round)/(Seats to be elected+1))+1, with any fraction disregarded.

"First-choice ranking tabulation round" means the stage of tabulation of first-choice rankings completed at each precinct on the voting system, pursuant to 1VAC20-100-50 A.

"Highest-ranked active candidate" means the active candidate assigned to a higher ranking than any other active candidates.

"Inactive ballot" means a ballot that can no longer be counted due to the ballot having no rankings remaining for active candidates.

"Instant runoff voting" means no more than one seat in the office must be filled by the election.

"Mathematically impossible to be elected," with respect to a candidate, means either:
(i) The candidate cannot be elected because the sum total of all votes credited to that candidate and to all candidates with the same number or fewer number of votes in that round is less than the number of votes credited to the candidate with the next greatest number of votes in that round; or
(ii) The candidate has a lower vote total than a candidate described in subparagraph (i).

"Maximum possible threshold" means the number of first-choice rankings from active ballots received in the first-choice ranking tabulation round sufficient for a candidate to be elected. The maximum possible threshold equals the total ballots cast for the office, including valid first-choice rankings, undervotes, skipped rankings, or overvotes for the office, divided by the sum of one plus the number of offices to be filled, then adding one, disregarding any fractions. Maximum possible threshold = ((Total ballots cast for the office)/(Seats to be elected+1))+1, with any fraction disregarded.

"Ranked choice overvote" means a voter assigned more than one candidate the same ranking.

"Ranked choice undervote" means a voter has left a ranking unassigned.

"Ranked choice voting" means a method of casting and tabulating votes in which (i) voters rank candidates in order of preference; (ii) tabulation of first-choice rankings and votes cast at other rankings is conducted; (iii) if the number of candidates elected after first-choice ranking tabulation is less than the number of offices to be filled, tabulation proceeds in rounds such that in each round either a candidate is elected or the last-place candidate is defeated; (iv) votes for voters' next-ranked candidates are transferred from elected or defeated candidates; and (v) tabulation ends when the number of candidates elected equals the number of offices to be filled. Ranked choice voting is known as "instant runoff voting" when electing a single office and "single transferable vote" when electing multiple offices.

"Ranking" means the ordinal number assigned on a ballot to a candidate to express the voter's preference for that candidate. Ranking number one is the highest ranking, ranking number two is the next-highest ranking, and so on, consecutively, up to the number of candidates indicated on the ballot.

"Round" means a stage of the vote tabulation, pursuant to 1VAC20-100-50 B or C, in which a person may be elected or the last ranked person defeated.

"Single transferable vote" means more than one seat in the office must be filled by the election.

"Skipped ranking" means an undervote on a ballot where a voter validly ranks a candidate at a subsequent ranking treated as provided in subdivision 2 of 1VAC20-100-40.

"Surplus fraction" is a number equal to the quotient of the difference between an elected candidate's vote total and the election threshold, divided by the candidate's vote total, (or (V-T)/V, in which "V" is the elected candidate's vote total and "T" is the election threshold), truncated after four decimal places.

"Surplus vote" means the number of votes a candidate receives beyond the election threshold set for a single transferable vote race.

"Tabulation" means the counting and, where necessary, transferring of votes cast in a ranked choice voting election that occurs in two stages:

1. Determination by voting system in the first-choice ranking tabulation round of first-choice ranking votes cast for each candidate and the creation of a record of votes cast at all ranking choices for each ballot cast.

2. Determination in a round, using the record of votes cast created by the voting system in the first-choice ranking tabulation round, of the votes to be transferred from eliminated candidates to active candidates, of the vote totals for active candidates after vote transfers, and of whether a candidate has received the number of votes sufficient to be elected.

"Transfer value" means the proportion of a vote that a ballot will contribute to its highest-ranked active candidate. Each ballot begins with a transfer value of one. If a ballot contributes to the election of a candidate under 1VAC20-100-50 C, it receives a new transfer value.

A. First-choice ranking tabulation round. For all elections for an office conducted by ranked choice voting, only first-choice rankings shall be counted in the first-choice ranking tabulation round. If any candidate has a vote total greater than or equal to the maximum possible threshold, that person shall be designated as elected. If the number of candidates whose vote total is equal to or greater than the maximum possible threshold is equal to the number of seats to be filled, those candidates are declared elected and tabulation in additional rounds shall not be conducted. If the number of candidates whose vote total is equal to or greater than the maximum possible threshold is less than the number of seats to be filled, tabulation shall proceed as set forth in subsections B and C of this section.

B. Instant runoff voting round. For any election for one office conducted by ranked choice voting, each active ballot shall count as one vote in each round for the highest-ranked active candidate on that ballot. Tabulation shall proceed in rounds with each round proceeding sequentially as follows:

1. If any active candidate has a majority of votes from active ballots in a round of tabulation, that person shall be designated as elected and the tabulation is complete.

2. If two or fewer active candidates remain, the candidate with the greatest number of votes is elected and tabulation is complete.

3. If more than two active candidates remain and no candidate has a majority of votes on active ballots in a round of tabulation, the active candidate with the fewest votes is defeated, votes for the defeated candidate are transferred to each ballot's highest-ranked active candidate, and a new round begins with subdivision 1 of this subsection.

4. Notwithstanding subdivision 3b of 1VAC20-100-40, more than one candidate may be defeated in a round by batch elimination, unless such batch elimination would result in only one continuing candidate, in which case no such batch elimination shall occur.

C. Single transferable vote round. For any election for more than one office conducted by ranked choice voting, each active ballot shall count, at its current transfer value, for the highest-ranked active candidate on that ballot. Tabulation shall proceed in rounds. Each round proceeds sequentially, until tabulation is complete, as follows:

1. If the sum of the number of elected persons and the number of active candidates is less than or equal to the number of office seats to be filled, then all active candidates are designated as elected, and tabulation is complete. Otherwise, the tabulation proceeds pursuant to subdivision 2 of this subsection.

2. If any active candidate has a number of votes greater than or equal to the election threshold for the contest, that person shall be designated as elected. Each ballot counting for an elected person is assigned a new transfer value by multiplying the ballot's current transfer value by the surplus fraction for the elected person, truncated after the fourth decimal place. The transfer value of each ballot cast for an elected candidate must be transferred to the highest-ranked active candidate on that ballot. Each person elected under this subdivision is deemed to have a number of votes equal to the election threshold for the contest in all future rounds and a new round begins pursuant to subdivision 1 of this subsection.

3. If no candidate or person is elected pursuant to subdivision 2 of this subsection, the candidate with the fewest votes is defeated and votes for the defeated candidates shall be transferred at their current transfer value to each ballot's next-ranked active candidate and a new round begins pursuant to subdivision 1 of this subsection.

D. Surplus transfer. If in a round of counting conducted under subsection C of this section, two or more active candidates have a number of surplus votes greater than the election threshold for the contest, the surpluses shall be distributed in rounds in which the largest surplus is distributed first, with any ties resolved by lot as required by § 24.2-674 of the Code of Virginia.

E. Tools, including software, used for tabulation in subsections B and C must be approved for use by the Department of Elections.