Player's Handbook[]
A character proficient in healing knows how to use natural medicines and basic principles of first aid and doctoring. If the character tends another within one round of wounding (and makes a successful proficiency check), his ministrations restore 1d3 hit points (but no more hit points can be restored than were lost in the previous round). Only one healing attempt can be made on a character per day.
If a wounded character remains under the care of someone with healing proficiency, that character can recover lost hit points at the rate of 1 per day even when traveling or engaging in nonstrenuous activity. If the wounded character gets complete rest, he can recover 2 hit points per day while under such care. Only characters with both healing and herbalism proficiencies can help others recover at the rate of 3 hit points per day of rest. This care does not require a proficiency check, only the regular attention of the proficient character. Up to six patients can be cared for at any time.
A character with healing proficiency can also attempt to aid a poisoned individual, provided the poison entered through a wound. If the poisoned character can be tended to immediately (the round after the character is poisoned) and the care continues for the next five rounds, the victim gains a +2 bonus to his saving throw (delay his saving throw until the last round of tending). No proficiency check is required, but the poisoned character must be tended to immediately (normally by sacrificing any other action by the proficient character) and cannot do anything himself. If the care and rest are interrupted, the poisoned character must immediately roll a normal saving throw for the poison. This result is unalterable by normal means (i.e., more healing doesn't help). Only characters with both healing and herbalism proficiencies can attempt the same treatment for poisons the victim has swallowed or touched (the character uses his healing to diagnose the poison and his herbalist knowledge to prepare a purgative).
A character with healing proficiency can also attempt to diagnose and treat diseases. When dealing with normal diseases, a successful proficiency check automatically reduces the disease to its mildest form and shortest duration. Those who also have herbalism knowledge gain an additional +2 bonus to this check. A proficient character can also attempt to deal with magical diseases, whether caused by spells or creatures. In this case, a successful proficiency check diagnoses the cause of the disease. However, since the disease is magical in nature, it can be treated only by magical means.
Player's Option: Skills & Powers[]
Characters with this proficiency can perform first aid on fresh wounds and can supervise the recovery of themselves and others. If the characters tend a wound on the round immediately after it is inflicted, a successful proficiency check means that 1d3 points of damage have been restored (to a maximum of the damage inflicted the previous round). If they tend a wound within one hour of its infliction, they can heal 1 point with a successful check. No character can benefit from this proficiency more than once a day.
This proficiency can also help with long-term healing and resisting poison and disease; these procedures are detailed in the Player's Handbook.
Note from The Complete Paladin's Handbook[]
A paladin's ability to heal by laying on hands (see Chapter 2) operates independently of this proficiency. A paladin with the Healing proficiency may use it instead of or in addition to laying hands on a damaged character. For example, a 2nd-level paladin with the healing proficiency could lay on hands to heal 4 points of damage, then use his healing proficiency to heal an additional 1d3 points.
The Complete Barbarian's Handbook[]
A barbarian with the healing proficiency may only diagnose and treat diseases common in his homeland terrain. He may not treat a poisoned individual unless the victim is suffering from a natural, nonmagical poison. He must also be familiar with the source of the poison. If the victim has been poisoned by a creature, the creature must be native to the barbarian's homeland terrain. If the victim has been affected by a poisoned weapon, the poison must be from a plant, animal, or mineral found in the barbarian's homeland terrain.
Campaign Option: Council of Wyrms Setting[]
Healing is described in the Player's Handbook. A successful check within one round of wounding restores 1d3 hit points (once per character per day); continued care automatically allows 1 (while traveling) or 2 (with complete bed rest) points of healing per day. Of course, a dragon learns to heal other dragons, so this proficiency cannot be used to aid any types of creatures other than a dragon's own kindred. A dragon with this proficiency can always try to help its own kindred.
If a dragon wishes, it can use additional slots to learn demihuman healing (for the same cost as the Healing proficiency). Demihuman healing covers dwarves, elves, and gnomes.
Hatchlings can't select this proficiency.