So the kosel was a question, but the Rebbes are definitely OK?
Regarding cards (which is what is really meant in this case), I am not aware of a prohibition specifically relating to the mode of gambling, rather only the gambling itself.
The halacha assumes that one only puts the money into the pot so as to qualify for winning the pot. Had he known that he would not win he would have not put the money in to begin with. Therefore it is stealing from the losers (who regret their bets) everytime you win.
Unless someone knows of another reason, I see nothing wrong with playing for chips and glory only (no money involved). Some people may say not to learn gambling games, but I personally don’t hold that is a problem.
There are exceptions for the laws of ribis when dealing with one’s immediate family (wife, children) and I always thought that there might be a tsu shtel to gambling – but I never asked a shaila on it, so I don’t know if I’m right.