List of electoral systems

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.

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
 * Winner-take-all system (winner determined by plurality voting): winner-takes-all systems (including all single-winner systems); no minority representation
 * Proportional
 * Semi-proportional
 * Other: sortition, etc.
 * Mixed system (yes/no)
 * Single-winner/multiple winner system
 * List / candidate (personal election) based system
 * Decision rule
 * Plurality (candidate or candidates with most votes wins, even if not majority of votes)
 * Majority (candidates must receive support at least half of voters)
 * Quota (candidates must at least reach the quota to be certain of election)
 * Type of ballot
 * single choice (voter can cast only one vote, whether for a candidate or for a party)
 * multiple choice (voter can cast multiple votes)
 * cumulative (voter can cast more than one vote for a candidate)
 * ranked (preferential voting; ordinal voting) (allows vote transfers)
 * score (cardinal voting)
 * Number of votes/voter
 * Number of tiers: number of levels e.g. local, regional, state, national