how do crit damage calculated?

[SuperbDave]

from my observation, any guaranteed add on damage (i.e. flat damage bonus) doesn't get double, but any dice damage (i.e. 1d4 damage on hit) get rolled twice and summed.

if this is correct, I should prioritise dices damage on a crit build?

[Sentient_Toaster]

Correct for 5E.

In practice, crits are pretty iffy to build for though. e.g. even if you're *always* attacking with advantage (e.g. melee barbarian who recklessly attacks, always), this gives you a ~9.75% chance to crit, since you need a natural 20 on either die.

OK, if you're not just an always-reckless barbarian, but an always-reckless halfling barbarian who multiclassed into fighter-3 for Champion so you reroll the first 1 on either die and crit on a 19-20... hm, that should give you a 10.5% chance to crit on 1d20 (10% of 19-20, 5% of roll 1 x 10% reroll is 19-20) for a ~19.8975% of a critical hit.

[Makkura]

A critical hit doubles *all* damage dice that directly belong to that attack. That is the dice you use from your weapon get rolled twice but also any extra dice you add due to abilities on the character.
The flat damage bonus does not get doubled. Any other roll that is not directly associated with the attack but triggered by the attack don't get doubled either.

[SuperbDave]

Originally posted by Sentient_Toaster:

Correct for 5E.

In practice, crits are pretty iffy to build for though. e.g. even if you're *always* attacking with advantage (e.g. melee barbarian who recklessly attacks, always), this gives you a ~9.75% chance to crit, since you need a natural 20 on either die.

OK, if you're not just an always-reckless barbarian, but an always-reckless halfling barbarian who multiclassed into fighter-3 for Champion so you reroll the first 1 on either die and crit on a 19-20... hm, that should give you a 10.5% chance to crit on 1d20 (10% of 19-20, 5% of roll 1 x 10% reroll is 19-20) for a ~19.8975% of a critical hit.

What I did was champion + spell sniper + the pink dagger that decrease crit roll requirement. so in theory, its 17-20 roll crit.

but the damage is kinda meh to be honest, its hard to add dice to spell, I built it on warlord, and extra base damage dice its negligible.

[EricHVela]

I'm wondering if they can mod a semi-popular house rule (I've only seen sometimes) where a crit means max damage on one die and roll the same die to add to it.

I agree with those DMs who do it that landing a crit but doing 2 damage instead of 11+ seems silly. So, hopefully modders can come to the rescue. (NOTE: Those DMs apply that kind of crit to player characters and NPCs/creatures alike.)

[Gewinnste]

Yes, you should prioritize the number of dice. A Paldin with high level Divine Smite yields the highest number of dice rolls and it's even D8s for the Smites. A level 3 Divine Smite will do ~10 D8 additional damage on a crit, if you are >Level 9 (I think) and even 2 D8 more against Undead. Also, if you have a Paladin, take "Luck of the Far Realms" - it allows you to get a crit at will, once per long rest. That means you can force 1 crit on any attack that was successful, and obviously this is the time to also trigger the highest level Divine Smite. It will often be a >100 damage hit!

[ctarioch28]

Crit builds tend to work better if you have a lot of dice (paladin, rogue) or have some sort of rider to crits (old one warlock). In my most recent playthrough, I ran astarion as a thief 3/ open hand 9 ascended him, and gave him soul catching gloves. That was 4 dice he was rolling, and with haste and wholeness of body he was getting like 10 attacks per turn.

[Emma]

This thread was quite old before the recent post, so we're locking it to prevent confusion.