Lucky Roulette

Next to your minimap (top right) below Cash Shop you will find Lucky Roulette icon.
In this minigame, you can spin by using Bronze Coin or Lucky Roulette Ticket obtained by chance from Lucky 3 Slotmachine, and from Daily Rewards.
You can turn the icon on and off via /roulette

You can get many goodies from Lucky Roulette such as:
Old Card Album
Mystical Card Album
Safe to 7 Armor Certificate
Safe to 8 Armor Certificate

How to play:
Double click your Bronze Coin or Lucky Roulette Ticket grant you one turn for the minigame.
Click the START button to start rolling.
As long as it does not stop at the last item on the left, you can choose to click START again to climb up the board.
You can instead clicking Get Prize if you land on the item you want or on the last item on the left, ending that turn of the minigame.

Extra: You will accumulate Roulette Silver Coin and Roulette Gold Coin as you play, which can let you start at higher rows (5th and 3rd row from the top respectively) but require ten coins per turn.
Note: You can not choose which type of coin you want to use first, the minigame uses all the bronze coin, then silver, then gold.