Instant-runoff voting
The South Australian House of Assembly has 47 members elected under the preferential Instant-runoff voting (IRV) system. If on the count of primary or first preference votes (votes marked with the number '1'), no candidate achieves more than 50% of the vote, the candidate with the fewest votes is excluded and their votes distributed according to the next available preferences, their 2nd or 3rd choice candidate. This process of exclusion continues until one candidate achieves 50% of the vote.