First-past-the-post voting

An electoral system in which voters usually choose one candidate in each district, and the candidate with the most votes wins without needing a majority.

Plurality voting: A voting rule that elects the option receiving more votes than any other, without requiring an absolute majority. First-past-the-post is the single-winner, district-based form of plurality voting.
Duverger's law: A political-science proposition that single-member plurality elections tend to favor two-party competition. The incentive to avoid wasted votes can concentrate support in two major parties.
Two-round system: An electoral system that holds a second vote if no candidate wins the required threshold in the first round. A runoff can ensure the final winner gains majority support among votes cast in the decisive round.
United Kingdom general election, 2024: A UK parliamentary election held on 4 July 2024, in which Labour won a large Commons majority with about one-third of votes. Its seat result illustrates how district victories can produce a large majority from a minority vote share.
Single-member district: An electoral district that chooses one representative. The system typically applies its winner-takes-all rule separately in each district.
Wasted vote: A vote that does not help elect a candidate, either because it exceeds the winner’s needed support or is cast for a loser. Votes for losing candidates do not translate into representation in a district.
Instant-runoff voting: A ranked-choice system that eliminates the lowest-ranked candidate and transfers votes until one candidate remains. Transfers let voters support minor candidates without the same direct spoiler risk.
United States House of Representatives: The lower chamber of the United States Congress, elected from single-member congressional districts. Its district elections commonly use the plurality rule described by this concept.
Plurality voting paradox: A situation in which a voting rule produces outcomes that conflict with a reasonable criterion of collective choice. Vote splitting can let a less broadly acceptable candidate win under plurality rules.
Disproportionality: A mismatch between parties’ shares of votes and their shares of elected seats. District-level victories can magnify a party’s seat share beyond its vote share.

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