[paranoidrobot]

> Nationals and Liberals. The opposing majority party is Labor. So here you have 3 parties

The Nationals are really only a separate party from the Liberals in name only. They don't (by and large) ever compete with the Liberals for seats, and where policies differ - it's because the Nationals have a view that's more representative of their regional constituent's views.

[hndamien]

Yes, but the more important distinction is the election structure which is not systematically designed to result in a two party system. "System" being the important word here, not "outcome".