Only one stone for each level. Again, they all give the same advantage, just that they have to be used in their level rooms.
"Bubbly Drop" (Beginner level)
"Bubbly Drop" (Normal level)
"Bubbly Drop" (High roller level)
When you use this stone, an extra ball will be spun along with the original one ^^
If all five players at the table use this stone, then a sixth ball will be added ^^
Example of when one stone is used:
The extra ball is in green.
You can click on the suitcase underneath your Casino$ amount to see how many stones you have and choose which you want to use.
Aside from randomly winning stones with your daily card pick, you can also buy them from this guy:
Beginner level stones: 30 AmeG/1 use; 130 AmeG/5 uses; 250 AmeG/10 uses
Normal level stones: 70 AmeG/1 use; 320 AmeG/5 uses; 600 AmeG/10 uses
High roller level stones: 120 AmeG/1 use; 540 AmeG/5 uses; 1,000 AmeG/10 uses