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).
Daily healing surge uses
The number of healing surges you can use per day depends on your class and Constitution modifier. The class you choose sets the base number and you gain a bonus from your Constitution, as well as any bonuses from feats or other effects. Any time your Constitution modifier rises, your number of surges rises as well.
The following feats increase the number of healing surges you have:
- The pathfinder paragon path available to rangers has a feature called Battlehoned, which increases your number of surges by 2.
- Combat Veteran's Tough As Nails path feature adds an additional healing surge.
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.
If you are out of healing surges, you can't use them to regain hit points. However, if you are dying and receive a healing effect that requires you to spend a healing surge, you can regain 1 hit point if you're otherwise depleted.
Healing surge value
The amount of HP a healing surge heals, known as your healing surge value, is 1/4th your maximum HP (rounded down). Some race features and feats can increase your healing surge value.
Effects that increase healing surge value
- The Dwarven Durability feat increases how much a dwarven character's healing surge value by his Constitution modifier.
- Dragonborn naturally add their Constitution modifier to their healing surge value.
- Taking a Dragonling as a familiar with the Arcane Familiar feat adds to an arcane character's healing surge value.
- Some powers that allow a target to spend a healing surge add to the surge value. For example, a power may add the user's Charisma modifier to the amount the target heals.
- Combat Veteran's Tough As Nails path feature adds your constitution modifier to surge value.
Regaining healing surges
You generally regain all your healing surges after completing an extended rest. Some effects like poison or failures in skill challenges (or any other conditions set by your DM) may prevent you from regaining all your surges.
Powers that allow spending a healing surge
- healing word
- healing strike
- bastion of health
- strengthen the faithful
- astral refuge
- mantle of glory
- spirit of health
- healing torch
- sacrificial healing
- lay on hands1
- paladin’s judgment
- martyr’s retribution1
- bloodied retribution
- death ward1
- united in faith
- life-giving smite
- inspiring word
- aid the injured
- stand the fallen
- inspiring reaction
- lion’s roar
- defensive rally
- warlord’s banner
- heroic surge
- defy death
Classes with the Channel Divinity class feature:
- 1 These powers have you spend a healing surge for another purpose, not healing yourself.
- 2 These powers are granted by taking a feat, and are available to characters with the Channel Divinity class feature (avenger, cleric, invoker, or paladin) who worship the corresponding deity.
Powers that heal "as though" spending a healing surge
- sustain life spark (paragon path feature)