A healing surge heals approximately 1/4th your max health when you use it. There are restrictions on when you can use a healing surge (such as in battle), and some effects can cause you to lose a healing surge without healing (poison, failure in a skill challenge, etc). Using Healing Surges Outside of combat you can usually use healing surges freely. After combat you must take a short rest before spending surges, and then you can spend any number you desire.
However, you cannot simply use a healing surge any time you please during combat. The following situations allow you to use one:
- You use your second wind.
- A power (either used by you or an ally) allows you to spend a healing surge. See the section below for a list of these powers.
- A power, effect, or item requires that you spend a healing surge as a cost (such as to renew an item's power, or to use a potion); doing so does not usually heal HP, at least not the normal amount. Potions use a healing surge to heal a set amount of HP independent of your surge value, be it higher or lower.
Note: Sometimes a power allows you to heal "as though" you had spent a healing surge. In this case, you heal your healing surge value but do not spend a surge doing so -- the healing comes free.