Like nearly all Wazdan slots, you can pick how you want to play by choosing low, medium or high volatility. Depending on which you choose will determine how frequent and how big your wins are, with the biggest wins coming with the high volatility option but coming less frequently.
You’re going to find a 4x3 layout in 12 Coins. The aim inside is to trigger a Hold the Jackpot bonus, where you go through several respins to claim a top jackpot of 750x the stake. You pick the slot’s volatility, which is the standard for Wazdan’s collection.
As mentioned, the game doesn’t form regular combinations. The 4x3 greed that is spinning are not even guaranteed to get symbols in all positions, and quite a few are usually empty. The bonus symbols are the stars, and the ones you want to see appear four times on the middle row. If that happens, you get the main feature, Hold the Jackpot.
An interesting mechanic, which could be helpful, is the Cash Infinity™ symbol. This lands on the reels and becomes sticky. If it lands on the middle row, it improves the odds of triggering the feature. They only go away at the end of the Hold the Jackpot respins. These symbols pay up to 10x the stake at that point.
As for Hold the Jackpot, it goes through 3 initial respins. Getting new bonus symbols to land will reset the respins back to 3. Each collected bonus symbol will pay up to 5x the stake. Getting three smaller fixed jackpots on the reels is also possible, which will pay 10x to 50x. The fourth jackpot pays 750x the stake, but you need all 12 bonus symbols on the reels for it to trigger.