# Mage Slayer *Source: Player's Handbook (2024) p. 205* **Prerequisite**: 4th You gain the following benefits. **Ability Score Increase.** Increase your Strength or Dexterity by 1, to a maximum of 20. **Concentration Breaker.** When you damage a creature that is [Concentrating](/Rules/Source/conditions.md#Concentration), it has [Disadvantage](/Rules/Source/variant-rules/disadvantage-xphb.md) on the saving throw it makes to maintain [Concentration](/Rules/Source/conditions.md#Concentration). **Guarded Mind.** If you fail an Intelligence, a Wisdom, or a Charisma saving throw, you can cause yourself to succeed instead. Once you use this benefit, you can't use it again until you finish a [Short](/Rules/Source/variant-rules/short-rest-xphb.md) or [Long Rest](/Rules/Source/variant-rules/long-rest-xphb.md).