Editing Two-round system (section)

=== Instant-runoff voting ===
{{main|Instant-runoff voting}}

[[Instant-runoff voting]] (IRV), like the exhaustive ballot, involves multiple reiterative counts in which the candidate with fewest votes is eliminated each time. Whilst the exhaustive ballot and the two-round system both involve voters casting a separate vote in each round, under instant-runoff, voters vote only once. This is possible because, rather than voting for only a single candidate, the voter ranks all of the candidates in order of preference. These preferences are then used to transfer the votes of those whose first preference has been eliminated during the course of the count. Because the two-round system and the exhaustive ballot involve separate rounds of voting, voters can use the results of one round to decide how they will vote in the next, whereas this is not possible under IRV. Because it is necessary to vote only once, IRV is used for elections in many places. For such as Australian general and state elections (called ''preferential voting''). In the United States, it is known as [[Ranked-choice voting in the United States|ranked-choice voting]] and is used in a growing number of states and localities.

In [[Republic of Ireland|Ireland]] it is known as the [[single transferable vote]] (STV) and is used for [[Irish presidential election|presidential elections]] and parliamentary elections. However, STV as applied in multi-member districts is a proportional voting system, not a majoritarian one; and candidates need only achieve a quota (or the highest remaining fraction of a quota), to be elected. STV is used in Northern Ireland, Malta, the Australian senate and various other jurisdictions in Australia.<ref>{{cite web |title=Proportional Representation Voting Systems of Australia's Parliaments |url=https://www.ecanz.gov.au/electoral-systems/proportional |url-status=live |archive-url=https://web.archive.org/web/20230302093736/https://www.ecanz.gov.au/electoral-systems/proportional |archive-date=2023-03-02 |access-date=2023-04-09 |website=ECANZ}}</ref> It is often used for municipal elections in lieu of more party-based forms of proportional representation.