There is a wide range of possible voting systems in the world today, some of which are currently in use, while others are strictly theoretical. These various systems can be broken down into three “families”: plurality semi-proportional and proportional systems. The voting systems within a particular “family” tend to produce similar outcomes and tend to resemble each other in terms of their advantages and disadvantages. The main differences are therefore between the families, not within them. The links below will take you to descriptions of these three “families” of voting systems, including sample ballots. For more detailed information on these systems and their political consequences, see Behind the Ballot Box: A Citizen’s Guide to Voting Systems.
Plurality/majority systems. These are the winner-take-all systems that are widely used in the United States. They include the common plurality systems like single-winner and at-large districts, and less common majority systems like the two-round runoff or “jungle primary.”
Proportional representation systems. These voting systems are used by most other advanced Western democracies and are designed to ensure that parties are represented proportionally (according to the share of the vote they win) in the legislature. They include party list systems, mixed-member proportional, and the single transferable vote.
Semi-proportional systems. These systems are used in some local elections in the United States. They tend to produce more proportional results than plurality/majority systems, but less proportional results than fully proportional systems. They include cumulative voting and limited voting.