You can carry that balance to any other slot machine and use any portion of that credit. If you were for instance to put a $100 bill into the machine to play, and then decide to stop after losing $50, you would simply cash out to your room card which would now have that balance of $50. You’ll need to choose a PIN number as kind of a password. Here’s how it works: You will need to use your room key to in the slot machine to set up an on-board bank associated with your card.