The voter puts a number by each candidate, with a one for their favourite, 2 for their second favourite and so on. They can put numbers on as many or as few as they wish.
If more than half the voters have the same favourite candidate, that person is elected. If nobody gets half, the numbers provide instructions for what happens next.
The counters remove whoever came last and look at the ballot papers with that candidate as their favourite. Rather than throwing away these votes, they move each one to the voter’s second favourite candidate. This process repeated until one candidate has half of the votes and is elected.
Other proportions, for example a two thirds majority can be used.
Other terms linked to Alternative vote include: Single transferable vote