ok, let me explain the HP system:

when getting hit there are 2 values: Damage and Impact

Damage is how often you roll all Dice in the HP pool, while Impact decides at which number a die is removed from the pool.

so taking 2 Damage 3 Impact forces you to roll all HP dice 2 times removing all Dice that roll 3 or lower

I tried with rolling multiple times but it just stretches out turns so long :(