How it works, precisely
First round: everyone votes for one option. If one clears the threshold (50 % by default in Placet, adjustable), it is over.
Otherwise a second round pits the top two against each other — the usual rule. French parliamentary elections use a different criterion: every candidate reaching 12.5 % of registered voters qualifies, which is how three-way runoffs happen.
In the second round an absolute majority is mechanically guaranteed: with two options, the plurality IS the majority. That is an arithmetic guarantee, not a guarantee of consensus.
A worked example
The same hundred people, this time over two rounds.
| Option | Round 1 | Round 2 |
|---|---|---|
| Lyon | 40 | 45 |
| Bordeaux | 35 | 55 |
| Lille | 25 | eliminated |
- Nobody reaches 50 %: Lyon and Bordeaux go through.
- Lille's 25 votes transfer: 20 to Bordeaux, 5 to Lyon.
- Bordeaux wins 55 to 45.
The runoff did correct the first round. But note what it did not do: had Lille been everyone's compromise second choice, it would have been eliminated in round one, never tested in a duel.
Where it comes from
The two-round system is a French nineteenth-century invention, generalised under the Third Republic. The Fifth Republic adopted it in 1958 for parliamentary elections, then in 1962 for the direct presidential election — first used in 1965.
The idea is a political compromise: keep the clarity of majority voting while fixing its most visible flaw, the minority winner. The runoff forces an explicit choice between two options only.
It spread far beyond France: Austria, Portugal, Brazil, Poland, most Latin American presidential elections, and a large share of French-speaking association ballots.
Where it is used
- The French presidential election and many other republics.
- French parliamentary and departmental elections.
- Association and union ballots, where an absolute majority is often required by statute.
- Weighty group decisions, when a clear mandate matters more than speed.
Limits and pitfalls
- The winner clears 50%
- You can vote with your heart in round one
- A familiar system
- Two ballots to run
- The third-placed could be a better consensus
- Unpredictable vote transfers
Frequently asked questions
Does the runoff guarantee real consensus?
No: it guarantees an absolute majority against ONE given opponent. If the duel on offer is the wrong one — because the compromise was eliminated in round one — the majority obtained is arithmetic, not political.
How can a candidate lose by gaining votes?
By changing their runoff opponent. Suppose you narrowly beat A but lose to B: a few extra first-round votes can eliminate A in favour of B and cost you the election. That is the monotonicity failure, and it is entirely demonstrable.
Two rounds or Condorcet?
Condorcet tests EVERY duel in a single vote, where the runoff tests just one, chosen by the first round. If your group can rank the options, Condorcet answers the same question more completely.