# Expertise *Source: Player's Handbook (2024) p. 367. Available in the Free Rules (2024)* Expertise is a feature that enhances your use of a skill proficiency. When you make an ability check with a skill proficiency in which you have Expertise, your [Proficiency Bonus](3-Mechanics/CLI/rules/variant-rules/proficiency-xphb.md) is doubled for that check unless the bonus is doubled by another feature. If you gain Expertise, you gain it in one [skill](3-Mechanics/CLI/rules/variant-rules/skill-xphb.md) in which you have proficiency. You can't have Expertise in the same skill proficiency more than once.