Australian hunt

The Australian hunt is an informal grouping of three online puzzle hunts: the MUMS Puzzle Hunt (written by Melbourne University Mathematics Society), SUMS Puzzle Hunt (written by Sydney University Mathematics Society), and Mezzacotta Puzzle Hunt (formerly the CiSRA Puzzle Competition, where CiSRA was a division of Canon in Australia). These hunts used to happen regularly every year until around 2013-2016.

Format similarities
In these three hunts, puzzles are released in batches of four or five puzzles every day for usually four to six days. Additionally, fixed hints would release for puzzles that have been unlocked for over a day, up to three hints. These hints would usually start relatively cryptic, hinting various steps of the puzzle obliquely, and would progressively become more straightforward in later hints. Solving puzzles would give a certain number of points, that would decrease for each hint released (regardless of if the team used the hint or not). Usually there is a single metapuzzle that uses all of the puzzles in the hunt.

Because all three hunts shared a common format, this style of hunt is sometimes colloquially referred to as an Australian-style Hunt, in contrast to a progression-based unlocking system. Some other examples include the first Galactic Puzzle Hunt, Edric's Puzzle Hunts, and the Tim Tang Puzzle Hunt. The Australian hunt format was also referenced in the Dreamtime round from the 2016 MIT Mystery Hunt.