>>37099020There is a random "lucky machine" which has slightly better odds but it doesn't make much difference.
There are 4 slot modes:
-bad (You will lose guaranteed)
-good (You will very likely win small prizes)
-super (Only mode where you can align 7 and bar, practically forces jackpot win)
-ultra (roll in good mode until you get 60 wins)
When you align 3 bars, super mode ends guaranteed
Here are the odds of each mode (rounded to 2 decimals, left col is normal, right col is lucky):
Bad: 78.13% || 78.13%
Good: 20.70% || 19.53%
Super: 00.78% || 01.95%
Ultra: 00.39% || 00.39%
When you align 3 7s, there is a 50% chance that you will get another super mode. Chaining these is the best way to earn coins imo.
Here's a vid for more details:
https://www.youtube.com/watch?v=u4fjbJnz7O4 
