A scam most-likely won't happen at long-standing casino, which already has good reputation. If you want to minimize risk - don't try freshly opened ones as there are decent amount of proven websites that offer options to satisfy anyone's needs.
Well I am little bit misunderstood with the concepts that you are talking about. Really, if you want to spot a scam then go for trading and investing and search out which ICOs are really harmful and scam that people must save themselves from. But if you are just trying out to save yourself from scam in gambling, this is still a loss for you that needs to be solved.