Critical Hits: How do you determine which dice to roll twice? - Rules & Game Mechanics - Dungeons & Dragons Discussion - D&D Beyond Forums (2024)

Here's the definition of a critical hit:

CRITICAL HITS
When you score a critical hit, you get to roll extra dice
for the attack's damage against the target. Roll all of the
attack's damage dice twice and add them together. Then
add any relevant modifiers as normal. To speed up play.
you can roll all the damage dice at once.
For example, if you score a critical hit with a dagger,
roll 2d4 for the damage, rather than Id4, and then add
your relevant ability modifier. If the attack involves other
damage dice, such as from the rogue's Sneak Attack
feature, you roll those dice twice as well.

So, when you critically hit, you double all of the "attack's damage dice" as well as all of the damage dice the attack "involves". I can't find any explanation anywhere of what the word "involves" is intended to mean.

Consider the radically different wording on the weapons of these two snakes, the flying snake and the poisonous snake:

Hit: 1 piercing damage plus 7 (3d4) poison damage. (Flying Snake)

Hit: 1 piercing damage, and the target must make a DC 10
Constitution saving throw, taking 5 (2d4) poison damage on a
failed save, or half as much damage on a successful one. (Poisonous Snake)

Do both snakes double their poison damage on a crit, or only one? If only one, how do you determine which snake's poison is "involved" in the attack and which is not? These are MM entries, so information is missing, but I am assuming both snakes are wielding 1-damage bites that have poison of some sort "added", much like a person might coat a weapon in poison. I was under the impression crits never apply to poison, but the flying snake's weapon has the same syntax as any weapon that deals mixed damage types, and all of those crit all of the dice (e.g. a flame tongue sword).

All of the dice involved in the attack's normal, non-critical damage get rerolled, regardless of their damage type or source (e.g. a spell, a class feature, some property of a magic weapon, etc.)

If the damage comes with a saving throw, ignore it, even if that saving throw depends on scoring a hit. That's a separate damage roll.

For the sake of completeness, also ignore any dice from features that directly increase your critical hit damage (e.g. Brutal Critical.) That's a bonus on top of your usual crit damage and not part of the attack's normal damage dice.

In this example the flying snake's poison damage gets rerolled but not the poisonous snake's.

"Saving throws can't score critical hits. If a saving throw is contingent on an attack hitting, the save is unaffected by that attack scoring a critical hit."

Quote from InquisitiveCoder >>

"Saving throws can't score critical hits. If a saving throw is contingent on an attack hitting, the save is unaffected by that attack scoring a critical hit."

Perfect, just what I wanted, thanks.

I wonder if there are any more examples like the two snakes, where the introduction of a save for half damage also nerfs the net damage of the attack even if the save fails.

The wyvern is another example. A more extreme one is the assassin which almost definitely crits at least once every combat thanks to its assassinate ability. The poison on its blades are powerful (or is the correct grammar here “is powerful?”) but because the poison does not crit as it is gated behind a save, it is not as much damage as it might otherwise be.

edit: forgot to mention it’s sneak attack dice would crit as well, if that wasn’t clear.

This is why pre-eratta Red Abishai nearly wrecked my entire 20th level party haha. Their bite used to do 5d10+6 damage (not including the fire) and add Incite Fanaticism to nearly double the crit rate...

A crit Bite was 10d10+6 piercing and 14d10 fire for an average of 138 damage. Hahahaha

I guess I'm after non-poison effects thatdon't have the wording on Ice Knife that separates out the damage rider into a distinct step (same wording as ice knife is on Psi Warrior Psionic Strike - unlike battlemasters, their damage won't crit, as it's a distinct step that deals damage a second time, rather than additional damage at the same time), so it's the save forcing the damage to stop critting, not the timing - almost all poisons work this way (the flying snake is the weird outlier I'm interested in), so e.g. the Wyvern just looks normal to me.

Anyone have any examples of non-poison where the target gets hit by an attack and then the attack deals two sources of damage at once, but the second source has a save so it can't crit? As mentioned above, examples where the second damage happens after the first damage don't count.

Quote from JoshtheDjinn >>

If that's the case, that would make a Barbarian's Brutal Critical extremely broken.

Barbarian's Brutal Critical tells you "Beginning at 9th level, you can roll one additional weapon damage die when determining the extra damage for a critical hit with a melee attack."

So Brutal Critical is a special case concerning criticals - only the weapon damage die, not any additional damage such as fireblade etc.

Quote from JoshtheDjinn >>

If that's the case, that would make a Barbarian's Brutal Critical extremely broken.

In what case and how?