Green’s Dictionary of Slang

(Aus.) a gambling game; thus troy school n., a gambling shop where the game is played.

1944		J. Devanny By Tropic Sea and Jungle 27: Tully was full of gambling joints, poker schools, troy schools [AND].
1948		H.W. Crittenden Rogues’ Paradise 155: In Queensland the police protection given to gambling shops called ‘troy schools’ is notorious [AND].
1961		Bulletin (Sydney) 22 Mar. 28/1: Ollie [...] had been unsuccessfully trying to live on the game (troy) in Cairns since he’d had his clavicle broken.