In reality, the hacked machine is not only a plausible scam, it's actually happened on multiple occasions. In the early nineties, dozens of slot machines were reprogrammed by Ronald Dale Harris, an employee of the Nevada Gaming Commission whose job it was to make sure such machines were fair.

The best way to increase your odds of winning on a slot machine is to not play. The probability of winning on any spin of the game is set by the game's program, and nothing you can do will affect that. The game is always set so that in the long run the machine will pay out less than what is wagered.

Due to the weak couplings of the Qt signals and slot mechanisms, it is viable to bind signals to each other. It may sound confusing, so let me draw a diagram to make it clear: When an event triggers a specific signal, this emitted signal could be another event, which will emit another specific signal.

As Andrei pointed it out, signal are only a redefinition of protected, meaning they can only be emitted by the class in which they are defined. Qt signals are public in the sense that any object can connect to any signal.