Ms Guy, who said she lost 14 years of her life to the pokies, was represented by law firm Maurice Blackburn to make her case in the Federal Court. The lawsuit claimed that design features of the "Dolphin Treasure" machine – including its uneven spread of symbols and the fact that the final reel has more symbols than the rest, allegedly making losses seem like "near misses" – were deceptive and misleading to gamblers. It also alleged that gamblers were misled by overall losses that were often disguised as wins, and by the machine's information about the theoretical rate of "return to player". Lawyers for Ms Guy argued that "Dolphin Treasure's" advertised return rate of 87.8 per cent gave the impression that a player would retain 87.8 per cent of the money they bet while risking losing 12.2 per cent, when, in reality, that figure was calculated over the lifetime of a machine and includes jackpots that occasional players rarely won. Loading

In the most damning part of her ruling, Justice Mortimer agreed with Ms Guy's claim that the "theoretical return to player" statements on the machines may be confusing to the ordinary gambler. She said it was likely to be construed as an indication of how much "he or she as an individual" might expect to receive during the gambling session. But that impression, Justice Mortimer said, would only be "fleeting". Justice Mortimer found the poker machine's design features did not amount to misleading or unconscionable conduct. "Any such impression formed would be dispelled as soon as she or he actually starts gambling and the randomness of the operation of the machine and returns become apparent".

"The impression is fleeting and may cause confusion but it is not misleading or deceptive as the law defines those concepts." Justice Mortimer found Crown and Aristocrat were compliant with consumer law, and had not engaged in the deceptive, misleading or unconscionable conducted alleged. Outside court, Ms Guy said she was grateful for her day in court, "on behalf of all Australians who have been hurt by the pokies". "I managed to get on top of my addiction but the sad reality is many people right across Australia can't do this, and the impacts are devastating," she said. "I'm hopeful this can lead to a better way forward."

'First of many decisions' Monash University professor of public health, Charles Livingstone, said he believed there would be many more cases against pokies companies to come. "This, to me, is like the beginning of the issues around tobacco control," he said. "It took 50 years or so, through a series of court cases and other actions for the harms of tobacco to be properly addressed, and I think this will be the first of what will be many decisions made by the courts that will reflect on this." Dr Livingstone said he was confident that, ultimately, "both the courts and governments will recognise the harm brought about by poker machines".

Aristocrat Leisure and Crown Resorts, had strongly rejected the allegations that gamblers may be misled by the machine’s design features, arguing it was "basic common sense" that symbols were unevenly spread across the reels and affected gamblers’ chances of winning. It was also argued that anyone unclear about how the pokies worked had "ready access" to answers, with explanatory information widely available in brochures on gaming-room floors and online. The industry argued that poker machines in Australia were heavily regulated and had to comply with some of the strictest standards in the world. "As we have said throughout, Aristocrat is a high-integrity business that takes our regulatory obligations extremely seriously," the company said in a statement to the stock market on Friday. "We strive to scrupulously uphold our obligations with respect to EGM [electronic gaming machine] compliance." Aristocrat said it supported fact-based harm-minimisation initiatives and committed to do more, "recognising that these issues are complex and require collaboration across industry, regulators and the community".