Gary Mifsud, publican at a public bar on Union Road, Ascot Vale, has known for eleven years that his pub is allowed to run an illegal gambling game once a year. He still checks the date three times before he lets anyone throw a coin.

Two-up, the coin-tossing game most Australians only ever see at Anzac Day dawn services and RSL halls, is otherwise a prohibited form of gambling under Victorian law. The exception, according to Victorian Gambling and Casino Control Commission guidance, is narrow and specific: RSL Sub-Branches may run two-up in the seven days before Anzac Day and on the day itself, while hotels, clubs and every other venue, including Mifsud's, are permitted to run it only on Anzac Day, and only with endorsement from a local RSL Sub-Branch and approval from RSL Victoria. Get the endorsement wrong, or the date wrong, and the ring of punters around a dropped coin stops being a tradition and starts being an offence.

"Every other day of the year, if I ran this game in my own bar, I'd be the one explaining myself to the Commission," Mifsud said, gesturing at a chalk circle on the floor that spends 364 days a year as an unremarkable patch near the pool table. "On the 25th of April, it's heritage. On the 26th, it's a problem. I find that quite stressful for a man who otherwise just pours beers."

Mifsud's preparation now rivals a small council event: RSL Sub-Branch sign-off confirmed by February, a spotter assigned to watch the clock, and a standing rule that betting stops the instant the pub's licensed trading conditions for the day say it should, since most liquor licences restrict alcohol service, and therefore gaming, before noon on Anzac Day unless a specific exemption applies.

Last year, a regular attempted to start a game on the morning of 24 April, having misread the pub's handwritten sign, and was gently informed by Mifsud that he was welcome to come back in roughly twenty-six hours, at which point an identical coin toss in an identical circle would switch, instantly and without anyone touching anything, from a criminal offence to a cultural institution.

"He asked what the actual difference was," Mifsud said. "I told him the difference was a date on a calendar and about a hundred years of careful lobbying. He said that seemed like a lot of effort for a coin toss. I told him to come back tomorrow."