Thank you for your feedback!
Several people struggle to understand all the UI directly and the little tutorial/instruction on the page didn't help.Next time I will do an in game tutorial for sure!
The effect of each card appear on top of the screen when you hover the card. Each [ ] on the instruction are a receptacle for a dice.
You cannot play the dice twice a turn, when you play a dice it disappear. So each turn you have 4 dice to spend on any card you want.