Does Joker cards stack? Or does my current one dissapear if I get another one.
You can have more than one Joker card at a time, see pic above.
I have had very good luck mainly with scratch game. I have played enough to win the Jia Lissa card and the Joker card, and during all that I have won enough 100 credits / 50 credits so that after all this, I have a one new Joker card, Jia Lissa's SEC, and more than a dozen new cards and I have more credits than I had before I started
Better stop now while being ahead in the game... (well, I'll better restock the credits also with that 20% reload bonus)...