In South Australia's House of Assembly elections, you must number every candidate in order of preference. Here's how your vote is counted and why preferences matter.
South Australia uses full preferential voting (also called instant-runoff voting) for the 47 House of Assembly seats. This system ensures the winning candidate has support from a majority of voters, either as their first choice or through preferences.
This is your first preference—the candidate you most want to win. Your vote goes to them first in the count.
If your first choice is eliminated, your vote transfers to this candidate. Think: "If I can't have my first choice, who would I want instead?"
Number all remaining candidates from 3 onwards. Even if you dislike some candidates, you must number them—put the ones you dislike most at the end.
Make sure every box has a different number, starting from 1 with no gaps. Then fold and place in the ballot box.
District of Example
Example ballot with all 5 candidates numbered
Drag candidates to reorder them and see how the count would work. This simulates a real preference count with 1000 voters.
Drag candidates up or down to set your preferences, then click "Run Count"
Click "Run Count" to see how preferences flow
In many SA districts, no candidate wins 50% of first preferences. When this happens, preferences decide the winner.
Imagine first preference results look like this:
No one has 50%+, so the count continues:
This is why your full preferences matter — your later preferences can decide close races, even if your first choice doesn't win.
If you only put "1" and leave other boxes blank, your vote is informal and won't be counted at all. You must number every box.
Writing 1, 2, 4, 5 (skipping 3) makes your vote informal. Numbers must be consecutive with no gaps.
Each number can only be used once. Writing "1" next to two candidates makes your vote informal.
You still must number all candidates. Put the ones you dislike most at the end—your vote is unlikely to reach them anyway.
You must still number them, but put them last. Your vote only reaches later preferences if all your earlier choices are eliminated. In practice, the count usually finishes before your vote reaches your last preferences.
Your vote only ever counts for ONE candidate at a time. It starts with your #1, and only moves to #2 if #1 is eliminated. Putting a candidate last doesn't "help" them—it just means your vote would only reach them if everyone else was eliminated first.
A "donkey vote" is when someone just numbers top-to-bottom as printed. Candidates are listed alphabetically by surname, so some voters accidentally preference based on ballot position. Take time to consider your real preferences!
Yes, parties and candidates hand out cards suggesting how to preference. You can follow these if you wish, but you're not required to—you can number candidates in any order you choose. The choice is yours.
House of Assembly uses full preferential voting (number all boxes) in single-member districts. Legislative Council uses optional preferential STV (you can vote 1 above the line, or number 12+ below the line) for statewide seats. Learn more about LC voting →
Now you understand how preferences work, explore who's running in your district.