The idea of changing what dice you use to try and roll is good. The problem is the game is so short and the die arnt different enough so there is no real reason to ever change the dice. Maybe if you only had one or even two dice, or one dice was like a two sided coin. That way using a bad dice or no dice in a slot would be a real sacrifice. Like this turn you need to heal so you have to either do less damage or take more damage to heal properly. As is; the dice are an interesting idea but which go in which slot isn't really an interesting challenge.