# Proficiency *Source: Player's Handbook (2024) p. 372. Available in the <span title='Systems Reference Document (5.2)'>SRD</span> and the Free Rules (2024)* If you have proficiency with something, you can add your Proficiency Bonus to any [D20 Test](Mechanics/CLI/rules/variant-rules/d20-test-xphb.md) you make using that thing. A creature might have proficiency in a skill or [saving throw](Mechanics/CLI/rules/variant-rules/saving-throw-xphb.md) or with a weapon or tool.