Originally, the game was similar to Saturday Lotto, requiring six numbers to be picked out of 45.
However, starting 18 October 2005, a seventh number began to be drawn, greatly lengthening the odds of winning Division 1.
Originally guaranteed at $100 million, four winners shared a Division 1 pool of $111,972,151.04 in the draw on 6 November 2012.
On 17 May 2022, Oz Lotto had its second major change to the game in its history, with the aim of delivering bigger prizes and more winners.
Oz Lotto guarantees a minimum division one prize pool of $3 million.