limitedrunoff

Limitedrunoff is an electoral design in which a second-round vote (a runoff) is held only if no candidate achieves a specified level of support in the first round, and the second round features only a subset of candidates rather than all who failed to reach the threshold. In practice, the runoff typically includes either the top two candidates by first-round votes or the top N candidates above a defined threshold.

The mechanism works by first round majority or plurality rules, followed by a restricted runoff if the trigger condition is met. The second-round process often uses the same voting method as the first round, but with a shorter campaigning period and a narrowed field. The design aims to balance the clarity of a two-round contest with considerations of cost, turnout, and administrative burden.

Variants vary by country and jurisdiction. Common forms include a top-two runoff, where the two leading candidates face each other regardless of vote share, and a threshold-based runoff, where only candidates above a certain percentage proceed to the runoff. Some systems allow only the finalists from the initial round to participate, while others cap the number of finalists.

Advantages cited for limitedrunoff include reduced election costs and less voter fatigue compared to multi-round contests, while preserving a majority or near-majority outcome. Critics argue it can still marginalize smaller parties, influence strategic voting, and depend heavily on the chosen thresholds. Related concepts include the two-round system and ranked-choice voting.