Heal the target a large amount of HP. The amount changes with the magic level and level of the user.
Most frequently, a player uses this rune on himself, but it can also be used to rescue a fellow player or a summoned creature from dying. On PvP game worlds only, it can be used to heal a hostile creature. This is often considered a dishonourable tactic and usually only done when the creature is attacking a player you extremely dislike, in an attempt to "anonymously PK" that player.
Druids or Sorcerers using this rune on themselves are guaranteed to completely heal because their magic power is a lot higher and their maximum hit points are much lower than knights or paladins of equal level.
Prior to the Christmas Update of 2007, this rune was widely used by Knights, however, many thousands of them became near useless after the update because it healed most knights less than the cheapest health potion.
This rune can be used by mages to heal their blocker. It will not heal as good as a Druid's sio, but may come in handy if the mage is low on mana.