When you suffer damage from a source such as a monster or a location, you and other characters may only do things that reduce or otherwise affect the specific damage type you’re suffering. (If a card says it reduces damage with no type listed, it reduces all types of damage.) For example, if you’re suffering Fire damage, you may play cards that reduce Fire damage or cards that reduce all damage, but you may not play cards that reduce only Combat or Electricity damage. Collectively, the party may play no more than one boon of each type to affect damage to the same character from the same source, although powers that say they can be played freely do not count toward that limit.
Determine the amount of damage to be applied, then choose that number of cards from your hand and discard them. If you don’t have enough cards in your hand, discard your entire hand.