This optional rule allows characters to heal up in
the thick of combat and works well for parties that
feature few or no characters with healing magic, or for
campaigns in which magical healing is rare.
As an action, a character can use a healing surge and
spend up to half his or her Hit Dice. For each Hit Die
spent in this way, the player rolls the die and adds the
character’s Constitution modifier. The character regains
hit points equal to the total. The player can decide to
spend an additional Hit Die after each roll.
A character who uses a healing surge can’t do so
again until he or she finishes a short or long rest.
Under this optional rule, a character regains all spent
Hit Dice at the end of a long rest. With a short rest,
a character regains Hit Dice equal to his or her level
divided by four (minimum of one die).