I'm not sure how this would be done, but hear me out. So people are always saying 'there is a one in two chance of winning' when there is really a one in sixty chance. I think you should have to be honest about the chances and prizes possible. It's not fair to people who spend money on something they think they have a 1/3 chance of winning when they don't. This might be hard, but I think it is necessary as telling people they could win something they can't is another way of scamming.
Casinos are all luck, the player should know what they're getting into and they can't call it a scam if they lost
I am going with the same thing Nyxa said, she has a point. People can run casinos however they want. It's always a risk, just like in real life. The players make their choice to chance their bets. It would be like setting rules for tradeshops. People that own tradeshops use their own discretion to decide what their trades are. Casino's are the same, the owner decides their own rules.
I have actually agreed with Nyxa on quite a few things, Nyxa has some good and valid points that I agree with sometimes. though I feel like your comment is unrelated to the post.
Therefore it is not really able to be enforced. If people were going to be honest, they would be honest already. Also, I do believe it is a little too much to ask to have to calculate percentages.
Players have already been banned for scamming through Casino contraptions. If you have doubts, ask a mod to check the dispensers or whatever is used. If they say 1/2 chances to win a Diamond (take a screenshot) and only one Slot has a Diamond it would be only 1/9 chances and therefore a scam. The Casinos which are least subject to scam are flower Casinos. Just make sure to check the biome to calculate your chances
The best and smartest way to avoid a "scamming" casino is avoid any casino's in general. Idk if you've ever been to a casino in real life, but it's your responsibility to know when to quit. Casinos aren't there to make you rich, they are in place to make the owner's rich. This is just like the lottery that has been implemented on the server since the last time I've played, if you know you have bad luck, it's best to find an alternative route to make grass instead of "gambling" it off even if it just costs 1 grass to buy a ticket. If 100 people buy a ticket that means you have a 1/100 chance of winning the grass. Same rules apply for the casinos.
The point of a casino is to test your luck. People know they have an unlikely chance of winning something with these so it's purely their decision whether or not to risk it or not. I don't think additional information is necessary.
You can't really get 'scammed' because it's completely up to you whether or not you enter a casino or not...lol.