Here you can see the payout system - Simply get 3 of any to appear, and the game pays out accordingly! The cost to spin is one nugget, making the common/lowest payout a "free spin" of sorts... though even that doesn't happen all the time!
This shot is a game result showing Apple-Melon-Apple... thus a loss. These items stay on the slabs for a brief moment before disappearing via MAGIC... ok, more like hoppers and redstone, but it's technical wizardry to be sure.
This next shot is a what a winning spin looks like. The prizes literally spit out of the picture and onto the floor, much like a real slot machine jackpot! For safety of your winnings, players are advised to use the machine one at a time.
I liked the idea of using gold as a currency so much that I decided to change up the ticket booth a bit. The two entrances now feature a drop box to place the proper amount of gold in before the door will open. In an adventure map setting, new players can start the game with some gold (via more command block magic), which they can use either to get in the race, hang out in the VIP area, or kick back in the stands.
In case anyone was wondering, here's a look at the slot machine in action, courtesy of Minecraftwithdummies on YouTube. It's super awesome!
I haven't officially added the roulette table yet, and I'm considering some other goodies as well such as a vending machine-based area to purchase items. I know 1.6 is officially out, but my computer is old and I'm kind of waiting on Optifine to update. Bear with me though, the races are almost ready!