Does a Barbarian with Brutal Critical get an extra 1d6 or 2d6 if they get a critical hit with a Greatsword?

Question

The Barbarian has the class feature Brutal Critical that reads:

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. (PHB 49)

The half orc has a similar racial trait as well (Savage Attacks).

This is a straight forward process if your weapon damage is a single die (great axe or smaller). However, with a greatsword, your weapon damage "die" is 2d6.

Does this feature mean you get to roll both d6s for the extra damage, or just one d6?

Answer 1

No, you only roll 1 additional die. The player's handbook is consistent in its use of the words 'die' and 'dice', where die is singular and 'dice' is singular or plural. A good example of this is on page 196 under Damage Rolls:

You roll the damage die or dice, add any modifiers, and apply the damage to your target.

There is also this quote that Rodney Thompson tweeted (thanks GMNoob) which states that it is intended to only be 1 die:

Also anyone that gets to roll one extra die on crits will favor the greataxe (like barbarians).

And Jeremy Crawford's tweet confirms this:

The barbarian's Brutal Critical gives the number of dice the feature specifies (greatsword gets 1 die to start).

Answer 2

Just one d6.

I don't see anywhere that it specifically defines "damage die" for a weapon, but the fact that you roll one extra die, then two and three, indicates to me that you should only roll one extra die (of same the number of sides as the damage die or dice of the weapon).

For a similar construction, see PHB 196 which describes rolling "the damage die or dice" of a weapon, spell, or harmful ability.

This is in contrast to 4e, which specifically says that the "W" of a weapon is equal to its total damage, so that "2W" would mean twice the number of dice.

Additional Justification

5e is a game where the rules try to homogenize a lot of roles. Most classes either use strong armor or have easy access to non-armor AC of 13 + a modifier. Everyone has the same proficiency bonus at the same level. Et cetera. The designers have called the general concept here "bounded accuracy," but I think it applies to damage as well.

If you roll 2d6 each time, then the multiplicative effect means that by the end you'd be rolling an extra 6d6 in comparison to barbarians using most weapons, who would be rolling an extra 3dX. This doesn't seem consistent with the even capabilities shown elsewhere in the system.

From a realism standpoint, my interpretation of the rule would mean that while a Greatsword does a ton of damage all the time, you can't squeeze much more extra damage out of it. There's a limit to how much harm you can cause, even as a lucky and skilled barbarian.

Final Note

Of course, this doesn't matter too much. It only happens on crit, and the expanded critical ranges come with Fighter, so it's only likely to be notably broken once you reach Fighter 3/Barb 9. 12th level is a good time to deal arbitrary amounts of damage.

Answer 3

You roll 1 additional physical die, in this case 1d6.

This makes weapons that do 1d12 more effective at criticals than the ones that do 2d6, which average a little more damage instead. I think this is done to differentiate the weapons. A criticals-focused fighter has more advantage with 1d12 weapons.

If instead the rules said that you could roll an extra 2d6, that would make the Great Axe almost useless, mathematically. In the 3.5 edition, for example, the Axe does 1d12 damage / ×3 criticals, while the Two-Handed Sword does 2d6/×2; in D&D 5e it is more or less the same: Axes are meant to be more "brutal" and a very good choice for Barbarians.

Answer 4

Roll an additional 2d6.

The "point" of weapons with multiple damage dice is increased consistency, not reduced total damage potential, which rolling only one of the dice would obviously be.

This is a case of "specific beats general". The general case of the casual language in the "one additional weapon damage die" is replaced by the corner case — the specific! — where a few weapons actually have more then one die for weapon damage.

I think the intent of the wording is that you only add this once, and not any other additional dice from any other source (for example, Sneak Attack damage, which is normally rolled a second time in 5e critical hits — you don't roll that yet again with this feature).

It would be completely reasonable for there to be some special, intentional rules reason to select axes over swords, but I don't think it is meant to be found in basically-obscure loopholes. The only thing like that currently is in the barbarian starting equipment list, which suggests a greataxe and handaxes (but which also allows other martial weapons). It would have been nice to see a feat or barbarian class feature instead, but it does not appear to be there.

Answer 5

Brutal Critical

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. […]

For a Longsword the weapon damage die is 1d8, so that's an extra 1d8.

For a Maul the weapon damage die is 2d6, so that's an extra 2d6.

That's how I read it.

Answer 6

My group is going with the extra 2d6 for a crit if using a greatsword. On page 45 of the PHB it looks like you would roll 1d6 for it but on page 197 of the PHB it does specifically say "Roll all of the attacks damage dice twice and add them together." It also goes in with the fact that it applies to ALL damage dice (but not modifiers) so if you are a rogue and get the Sneak Attack 1d6, on a crit, you'll still roll that one a second time (so 2d6). Seeing as that the example it gives with a rogue has them rolling 2 damage die for the attack (the sneak attack 1d6 and the daggers 1d4) twice. So we've applied that example to crits for our barbarian using a greatsword (as such a crit would be 4d6, 6d6, 8d6, and 10d6 at base/9/13/17).

I guess it really comes down to your DM and whether they will let it slide or if it's just 1d6 per crit (and brutal crit).