I repurposed Luck as "Wisdom". It is the attribute that determines the effectiveness of White Magic (healing spells). My game has a class based mechanic that can be altered by junctioning Avatars (summons). If you junction an Avatar, you gain a small spell repertoire if you didn't have it before or it becomes wider if you already had a spell list. So a character who is not a White Mage or Paladin can access healing spells. However, only certain classes with high Wisdom are any good with healing spells.