I think it means that you can't play with the intention of winning, but must play and expect to lose. Of course, surely EVERYONE intends to be the lucky SOB that hits big and gets paid, as if people were told they could never ever withdraw winnings, but that they would just win the right to have more "entertainment" time with the extra coins, they would have a sharp fall in deposits. It wouldn't fall to zero though as some Facebook slot apps allow coins to be bought with real money, and there is no means to actually win and withdraw any real money, yet people still pay to play.
The term does seem to get used to confiscate winnings due to "professional play" or "playing style", and is often used to shut down sports betting accounts.
What about poker though, this is pushed as a game of skill, and one with "professional players", and poker operators have tried to legally argue that it's a game of skill in order to stop it being classed as "gambling" by places like the USA, and thus banned.
Despite this, they then try to argue that there is such as thing as a professional slots player, professional roulette player, etc because a few lucky players manage to have an extreme run of luck that is unbelievably close to the end of the distribution tail, so the casino starts to believe the snake oil salesmen and claim such players "abused patterns in past results" or similar BS in order to generate such luck. They then slam into reverse when it is suggested that a very BAD run of luck is down to the games being "compensated" in order to preserve profit, or "rigged" in some other way.
Simply having some odd terms can suggest that casino operators don't trust the random nature of their games, but they should realise that it works both ways, PLAYERS will question the fairness of the games if they see terms that appear to protect casinos against something that isn't possible with a random suite of games.
) that this part of the clause would not be held enforcable in any reasonable court of law.
