Green’s Dictionary of Slang

1. (Aus.) a gambling game, either using dice or, in a form of ‘two-up’, threepenny pieces; also attrib.

1905		Sun. Times (Perth) 17 Sept. 4/8: Humorists, these sports. One of them landed in Kalgoorlie with a wealth of hope, and enough to see him into the ‘peter’ school. He had faithfully promised his wife to send her a fiver when he got ‘in the play’.
1905		Sun. Times (Perth) 22 Oct. 4/8: Spend his money on the bar, not much, he don’t, you bet. It's bad enough to do it, in at the races or Peter School.
1907		Sun. Times (Perth) 21 July 4/8: O, peter school parasite grimy who hopes / To pick up a quid in the flutters .
1921		Sun. Times (Perth) 6 Mar. 4/6: Next the lover, tearing himself occasionally away from his peter school to take her to the pitchers.
1924		Mirror (Perth) 26 July 2/1: Above the clatter of crockery and the occasional bursts of laughter, can be heard references to the ‘Peter School’, chatter about ‘throwing mains’, ‘breaking the bank’, ‘setting the box’, and the like [...] This is how the game of hazards is played. One player takes the little box containing the two dice and throws for what is termed a ‘main’.
1938		Press (Canterbury) 2 Apr. 18: A ‘peter school’ is a gambling den.
1939		Morning Bull. (Rockhampton, Qld) 28 Aug. 11/6: Use of a private residence at Alderley as a ‘trey bit peter’ school was detailed in the Police Court yesterday, when 19 men were charged that they were found an August 25 without lawful excuse in a common gambling house. ‘Trey Bit Peter’, it was explained subsequently, is a game with three 3d. pieces thrown from a dice box, and results are determined similarly as in two-up, by heads or tails.

2. (Aus./N.Z., also peter joint) a gambling den.

1906		Sun. Times (Perth) 16 Sept. 4/7: For the ‘push’ only. Notorious peter joint is now known as the ‘acid school’.
1941		Baker Popular Dict. Aus. Sl.