Armor Class

D&D 2024 rule: Armor Class. Source: Player's Handbook (2024). rule type Core An Armor Class (AC) is the target number for an attack roll. AC represents how difficult it is to hit a target. Your base AC calculation is 10 plus your Dexterity modifier. If a rule gives you another base AC calculation, you choose which calculation to use; you can't use more than one. Core