when do you get a critical hit in dnd

In D&D, you usually get a critical hit when you roll a natural 20 on an attack roll, meaning the die shows 20 before any modifiers are added. A crit also means the attack automatically hits, and you normally roll extra damage dice rather than adding only flat bonuses.

How it works

• It applies to attack rolls, not most ability checks or saving throws.

• On a crit, you double the damage dice you roll, but not fixed modifiers like a flat damage bonus.

• Some classes or features can expand the crit range; for example, one source notes Champion fighters can crit on 19–20 at certain levels.

Simple example

If your attack normally deals 1d8+31d8+31d8+3, a critical hit would usually become 2d8+32d8+32d8+3.

TL;DR: roll a natural 20 on an attack roll, and you crit.