Do you want to make a casino, but you're unsure how? You could use a pig randomizer to make slot machine, but that takes complicated redstone circuitry. This simple slot machine design utilizes the dispenser's randomized item firing.
The structure consists of three blocks of your choice, three stone buttons, and three dispensers in this pattern:
D=Dispenser B= Block with button on it
Create a prize system out of gold. For example: push the button under every dispenser. You will get a nugget, ingot or block from each. It is more likely to get a nugget because nuggets should fill more slots in the dispenser, and more likely to get ingots than blocks. If you get a three nuggets in a row from the dispensers, you can trade them in at a counter in your casino for prizes like diamonds or iron ingots. Note: You should keep an eye on your players in case they try to steal from the dispenser.
You may want to put more slot machines in your casino, with different difficulty levels. Or, for a dangerous spin, add one slot in your dispenser full of fire charges for the unlucky.