Green’s Dictionary of Slang

puzzler n.

(Aus.) a form of crooked die.

[Aus]Mirror (Sydney) 31 Aug. 8/2: The dice have their own foibles. If anyone asked what puzzlers were, probably the name would be enough to tell him what their part in the game was. They only throw certain mains [i.e. totals], and the player is always sure of a win.