Critical hits happen when a player rolls a 20 on an attack roll, causing the attack to automatically hit and doubling the amount of damage dice rolled to determine the attack’s damage.

For example, if you land a critical hit with a scimitar, you roll 2d6 instead of 1d6, and then add your attack ability modifier. You do not double the attack modifier; only the damage dice rolled.

Critical hits include all damage dice, so if a Paladin hits with a warhammer, Searing Smite active, and uses Divine Smite when they crit, they would deal damage equal to 2d8 bludgeoning + 2d6 fire + 4d8 radiant + their Strength modifier.

Now you can see why Paladins and Rogues with Sneak Attack love to land critical hits so much!

Player’s Handbook, pg. 196 + 194

Matt Zane

Author, DnD Lounge

Matt Zane started DnD Lounge in 2021. Matt began playing DnD 5e in 2015, and has been DMing since 2017. He loves optimization, but also enjoys looking for creative ways to use spells and abilities that follow the spirit and letter of the rules. He also eschews pure optimization in favor of a more balanced approach, where building a character is primarily about serving an interesting story arc and party dynamics rather than maxing out DPR.