Tenacity

is used when you would die or in high stress situations.

You roll 1D20 and on a 20 you either gain the tenacity value to your next X desired rolls where X is 1+(tenacity/4).

this can be rolled for once per point of tenacity per day.

If you would otherwise die you MUST roll all available rolls on tenacity, on a roll of 20 you regain HP equal to your Tenacity value *10.