20th Level Mage or Priest Group
You gain the following benefits: Ability Score Increase. Increase your Intelligence, Wisdom, or Charisma score by 1, to a maximum of 30. Free Casting. Whenever you cast a spell with a Spell Slot of 1st, 2nd, 3rd, or 4th level, roll a d4. If the number you roll equals the slot’s level, the slot isn’t expended.