Credit system
This is something to keep in mind when the player on the next machine over tries to tell you that the machines are looser on weekends and tighter on weekdays. The truth is that, if we assume that all the casinos are playing by the rules, the machines haven’t a clue what day of the week it is, or what time of the day.
The machines are allowed to have mechanisms that keep track of which player is on the machine—a credit system using the Slots Player Card. This mechanism can be attached to a clock and a calendar. Connecting the clock and calendar to the computer chip determining payoffs would be illegal, however.