One of the questions I'm often asked is how do you know when to stop playing.  This is not an easy question to answer.  It is a good idea to go in with a plan.  But, it is tough to give a one size fits all answer.  Some people have in mind an amount of time they want to gamble.  Others say that they'll only lose a certain amount.  Both of these are part of the reason why they can build multi-billion dollar casinos.