Clocks, Daylight and any possible check you have on reality. What they give you to encourage you to stay and play are perks. Free drinks, hotel upgrades, anything to keep you at the tables or machines and playing. You have no idea what time it is, how long you've been playing or whether its night or day so free food and drink is given to keep you right where you are, they don't want you leaving for a coke and a burger.
You will only leave when all your money is gone. The house always wins sooner or later and the house knows more about maths and psychology than you could ever know.
You cannot win.