Hero points work well in epic fantasy and mythic
campaigns in which the characters are meant to be
more like superheroes than the average adventurer is.
With this option, a character starts with 5 hero points
at 1st level. Each time the character gains a level, he or
she loses any unspent hero points and gains a new total
equal to 5 +half the character’s level.
A player can spend a hero point whenever he or she
makes an attack roll, an ability check, or a saving throw.
The player can spend the hero point after the roll is
made but before any of its results are applied. Spending
the hero point allows the player to roll a d6 and add it
to the d20, possibly turning a failure into a success. A
player can spend only 1 hero point per roll.
In addition, whenever a character fails a death saving
throw, the player can spend one hero point to turn the
failure into a success.