Part of the Politics series
Electoral systems
Single-winner/majoritarian Plurality First-past-the-post Plurality at-large (plurality block voting) General ticket (party block voting) Multi-round voting Two-round Exhaustive ballot Primary election Nonpartisan unified top-four Majority at-large (two-round block voting) Ranked / preferential systems Instant-runoff (alternative vote) Contingent vote Coombs' method Condorcet methods (Copeland's, Dodgson's, Kemeny–Young, Minimax, Nanson's, ranked pairs, Schulze, Alternative Smith) Positional voting (Borda count, Nauru/Dowdall method) Bucklin voting Oklahoma primary electoral system Preferential block voting Cardinal / graded systems Score voting Approval voting Combined approval voting Unified primary Usual judgment Satisfaction approval voting Majority judgment STAR voting
Proportional representation Party-list Electoral list open list closed list local lists Apportionment Sainte-Laguë D'Hondt Huntington–Hill Hare Droop Imperiali Hagenbach-Bischoff National remnant Highest averages Largest remainder Proportional forms of ranked voting Single transferable vote Gregory Wright Schulze STV CPO-STV Ranked party list PR Spare vote Proportional forms of cardinal voting Proportional approval voting Sequential proportional approval voting Method of Equal Shares Phragmen's voting rules Biproportional apportionment Fair majority voting Weighted voting Direct representation Interactive representation Liquid democracy
Mixed systems By type of representation Mixed-member majoritarian Mixed-member proportional Non-compensatory mixed systems Parallel voting Majority bonus Compensatory mixed systems Additional member system Mixed single vote (positive vote transfer) Scorporo (negative vote transfer) Mixed ballot transferable vote Alternative Vote Plus Dual-member proportional Rural–urban proportional
Other systems and related theory Semi-proportional representation Single non-transferable vote Limited voting Cumulative voting Binomial voting Other systems Multiple non-transferable vote Double simultaneous vote Proxy voting Delegated voting Indirect STV Liquid democracy Random selection (sortition, random ballot) Supermajority Social choice theory Arrow's theorem Gibbard–Satterthwaite theorem Public choice theory Veto Players List of electoral systems List of electoral systems by country Comparison of electoral systems Effects of electoral systems Political fragmentation Political efficacy Voter turnout
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An electoral system (or voting system) is a set of rules that determine how elections and referendums are conducted and how their results are determined.

Some electoral systems elect a single winner (single candidate or option), while others elect multiple winners, such as members of parliament or boards of directors.

The study of formally defined electoral methods is called social choice theory or voting theory, and this study can take place within the field of political science, economics, or mathematics, and specifically within the subfields of game theory and mechanism design.

List of electoral systems by types

Key

• Name (abbr.) and other names of the system (other names that may sometimes refer to other systems)
• Type of representation: the most common division of electoral systems
  • Majoritarian: winner-takes-all systems (including all single-winner systems)
  • Proportional
  • Semi-proportional
  • Other: sortition, etc.
• Mixed system (yes/no)
• Single-winner/multiple winner system
• List / candidate (personal election) based system
• Decision rule
  • Plurality (candidates with most votes win)
  • Majority (candidates must receive support at least half of voters)
  • Quota (candidates must at least reach the quota)
• Type of ballot
  • single choice
  • multiple choice
  • cumulative (more than one vote for one candidate possible)
  • ranked (ordinal voting)
  • score (cardinal voting)
• Number of votes/voter
• Number of tiers: number of levels e.g. local, regional, state, national

Systems

List of electoral systems used for national elections

Electoral system for national legislatures (lower house or unicameral)
Majoritarian representation (winner-take-all)   Proportional representation   Mixed-member majoritarian representation   Mixed-member proportional representation   Semi-proportional representation (non-mixed)   No election (e.g. Monarchy)