Ranked-Choice Voting Explained

Ranked-choice voting (RCV) is a ballot system in which voters order candidates by preference rather than selecting a single name. This page covers how RCV is defined in election administration, the mechanics of tabulation rounds, the scenarios in which it applies, and the decision boundaries that distinguish it from other voting systems. Understanding these distinctions is foundational to the broader landscape of election types and voting systems covered across this reference.

Definition and scope

Ranked-choice voting is a tabulation method in which a ballot records a voter's ordered preferences — first choice, second choice, third choice, and so on — rather than a single selection. If no candidate receives a majority of first-choice votes after the initial count, the candidate with the fewest first-choice votes is eliminated, and ballots that ranked that candidate first are redistributed to whichever remaining candidate those voters ranked next. This process continues until one candidate crosses the majority threshold.

The term "instant-runoff voting" (IRV) is often used interchangeably with RCV in single-winner contests. The distinction matters in multi-winner contexts, where the system is more precisely called the Single Transferable Vote (STV). Both IRV and STV fall under the broader RCV umbrella recognized by the National Conference of State Legislatures (NCSL).

As of 2024, Maine and Alaska use RCV for statewide and federal general elections (NCSL, Ranked-Choice Voting). Alaska adopted RCV alongside its top-four primary through Ballot Measure 2 in 2020. Maine extended RCV to presidential general elections through a 2020 referendum. More than 50 U.S. jurisdictions — spanning cities and counties — use RCV for local contests, including New York City for its mayoral primaries.

How it works

The tabulation process follows a defined sequence of elimination rounds:

1. First-choice count — Every valid ballot is counted for the candidate marked as the voter's first preference. Ballots that are left completely unmarked in a round are classified as exhausted and set aside.
2. Majority check — If any candidate holds more than 50 percent of active (non-exhausted) ballots, that candidate wins and tabulation ends.
3. Elimination — The candidate with the lowest first-choice total is eliminated from the contest.
4. Ballot transfer — Ballots that ranked the eliminated candidate first are moved to the next-ranked candidate still in the race on each ballot.
5. Repeat — Steps 2 through 4 repeat until one candidate achieves a majority of active ballots.

A ballot becomes exhausted when every ranked candidate on it has been eliminated before a winner is determined. High rates of ballot exhaustion — which the MIT Election Data and Science Lab has studied in municipal contests — can affect the legitimacy threshold of the final majority figure, since that majority is calculated against active, not original, ballots.

Tabulation can be conducted by hand in small jurisdictions, but most jurisdictions relying on RCV use certified voting equipment capable of reading and processing ranked ballots. The U.S. Election Assistance Commission (EAC) provides guidance on voting system certification standards that apply to RCV-capable equipment under the Help America Vote Act (52 U.S.C. § 20901).

Common scenarios

Multi-candidate primaries — RCV is most frequently adopted where primaries involve five or more candidates and a plurality winner might capture as little as 20 to 25 percent of the vote. New York City's 2021 Democratic mayoral primary featured 13 candidates on the RCV ballot, illustrating this dynamic directly.

Closely contested general elections — In Alaska's 2022 U.S. House special election, no candidate reached 50 percent after the first round. Tabulation proceeded to a second round before a winner was determined — the first federal House election in U.S. history decided by RCV (Alaska Division of Elections).

Local nonpartisan elections — Cities including Minneapolis, Minnesota and San Francisco, California use RCV for municipal races where partisan affiliation does not appear on the ballot, reducing the spoiler dynamic associated with plurality voting.

Multi-winner proportional contexts — Cambridge, Massachusetts uses STV for its city council elections, a system that has been in continuous operation since 1941 and allocates 9 council seats proportionally across the ranked ballot pool.

Decision boundaries

RCV differs from adjacent systems along two critical axes: how a winner is defined and how votes transfer.

RCV vs. plurality voting — In a standard plurality (first-past-the-post) system, the candidate with the most votes wins regardless of whether that total constitutes a majority. No vote transfer occurs. RCV requires a majority of active ballots and uses iterative transfer to reach that threshold.

RCV vs. traditional runoff elections — A traditional runoff requires a separate election event, typically held weeks after the initial contest, involving only the top two finishers. RCV accomplishes mathematically equivalent redistribution within a single ballot event, eliminating the cost and turnout decline associated with separate runoff elections. Research published by the Fairvote organization — a nonpartisan nonprofit that studies electoral systems — documents turnout drops between 10 and 40 percentage points in traditional two-round runoffs compared to the original election.

RCV vs. approval voting — Approval voting allows a voter to mark as many candidates as desired, each receiving equal weight. RCV preserves preference ordering, meaning a voter's second choice only activates after their first choice is eliminated — a structural distinction that affects strategic voting incentives.

Ballot design constraints — Most U.S. RCV implementations cap the number of rankable candidates between 3 and 6 positions, regardless of how many candidates appear on the ballot. This cap is a design and equipment constraint, not a statutory requirement of RCV as a system, and it directly affects ballot exhaustion rates in crowded fields.

Jurisdictions considering RCV adoption must also address whether existing state statutes authorize the method. Several states have enacted statutory restrictions or outright bans on RCV for state and local contests, creating a patchwork of permissibility that intersects with election administration and oversight frameworks at the state level.