D&D 5E Great Weapon Mastery - once more into the breach! (with math)

[FrogReaver]

The math indicates otherwise

What math indicates that precision attack isn't the go to DPR maneuver for any fighter that uses a weapon bigger than a non-magical dagger?

Precision attack has the same effect at virtually all to-hit values (at least without advantage). That is the magnitude of the increase in DPR it causes doesn't change if your chance to hit the monster changes.

I'll admit I've not found a perfect way to factor precision attack into an advantaged fighter and so I have been using the assumption that it works the same with the advantaged fighter as it does with the unadvantaged. If you can show it doesn't work that way I would be happy to see that.

 

[FrogReaver]

[MENTION=23]Ancalagon[/MENTION]

I think the problem is your severe under-estimation of precision attack. Without precision attack I wouldn't be nearly as concerned with GWM. GWM using fighters just don't typically get enough attack on their own to compensate against even moderately good AC opponents. Precision attack fixes that. It's easier to watch in action on a simulation with a parameter about when to use it that changes with your number of attacks and the number and size of your maneuver dice. You can play around with most every variable you want and you should find exactly what I did when I simulated it. Smart use of the feature generates about +15% chance to hit over the whole day. A very high percentage of attacks you use precision attack on will become hits. Probably 75-80% or more of the dice will turn hits into misses. Until you are making a lot of attacks it is very unlikely you use all your superiority dice on precision attack because good opportunities to use it will not come up that often in the day. Even so, you will still be increasing your daily to hit rate by about 15%.

Keep in mind. In a day you make 20 attacks you only need to turn 3 of them from misses into hits (about 20 rounds of combat). If you are level 5+ and now make 40 attacks you still only need to turn 6 of those misses to hits to increase your effective chance to hit by 15%. Well I think you get the idea. Since your chance of turning a miss into a hit is so high on "good" misses then you will only use maybe 8 superiority dice to turn 6 misses into a hit out of 40 attacks.

 

[Ancalagon]

[MENTION=6795602]FrogReaver[/MENTION]. Here are some details about the impact of precision attack

First, you need to know the odds of each number (1-20) being rolled with advantage. The odds are as follows. The chance of rolling 1 are 1/400. The chance of rolling 2 are 3/400. The chance of rolling 3 are 5/400.... all the way to 20, which is 39/400

(btw, I *reaaalllly* recommend excel or similar program for this!)

So let's say your character has a +4 bonus to hit, has advantage, and is trying to hit AC 16. You need to roll 12 or higher. With advantage, your chances of doing that are 0.6975 (I trust you all know how to do this math right?). So if you roll 12 of above, no point of rolling a precision maneuver - you hit already! If you rolled 3 or less, there is again no point - 3+8 =11, a miss, so why bother. So it's only in that 4-11 range that you want to take that precision maneuver dice and add it to your roll.

If you roll a 3, you need an 8. there is 1/8 chance of this helping you. If you rolled a 4, you need a 6, so 2/8... all the way to 8/8 if you rolled an 11, where the precision dice is *guaranteed* to help you.

So what you do is you take your column of 1-20 numbers, the column of probabilities, and you line them up, and multiply.

So if you roll a 3 - there is a 5/400 chance of this occurring, there is a 1/8 chance of the roll being an 8, you multiply, so this "helps" you by a fraction of 0.0015625... not very much - but you repeat this process for 4, 5... all the way to 11, and then you add the fraction. In this case, the sum is 0.16125. This sum is then added to 0.6975, resulting in a new to hit chance of 0.85875.

(edit: I just noticed, this means your estimate of 15% was quite good... but please keep in mind that this varies based on the AC so if I had picked a different AC it would have been a bit different)

Another way of looking at it is that with advantage, you had 0.3025 chances to *miss*. And in this case, it turns out that hey, in this case [MENTION=12731]CapnZapp[/MENTION] is correct, this is roughly reducing your chance of a miss by half... but this does *not* double your damage, it only goes from 0.6975 to 0.85875 of the "base" damage.

So yeah, this maneuver helps a GWM warrior a fair bit... BUT a warrior who is not using GWM can use that maneuver dice to increase his or her damage instead! I've compared that in my previous posts. The GWM still come out a bit ahead. but it is NOT +10 damage per attack, not even close.

I hope this answers your question.

 

[Ancalagon]

I will note that I did not compare Precision vs Precision + GWM. My gut feeling is that it would not have helped as much as a damage dice, but I may be wrong.

 

[FrogReaver]

@FrogReaver. Here are some details about the impact of precision attack

First, you need to know the odds of each number (1-20) being rolled with advantage. The odds are as follows. The chance of rolling 1 are 1/400. The chance of rolling 2 are 3/400. The chance of rolling 3 are 5/400.... all the way to 20, which is 39/400

(btw, I *reaaalllly* recommend excel or similar program for this!)

So let's say your character has a +4 bonus to hit, has advantage, and is trying to hit AC 16. You need to roll 12 or higher. With advantage, your chances of doing that are 0.6975 (I trust you all know how to do this math right?). So if you roll 12 of above, no point of rolling a precision maneuver - you hit already! If you rolled 3 or less, there is again no point - 3+8 =11, a miss, so why bother. So it's only in that 4-11 range that you want to take that precision maneuver dice and add it to your roll.

If you roll a 3, you need an 8. there is 1/8 chance of this helping you. If you rolled a 4, you need a 6, so 2/8... all the way to 8/8 if you rolled an 11, where the precision dice is *guaranteed* to help you.

So what you do is you take your column of 1-20 numbers, the column of probabilities, and you line them up, and multiply.

So if you roll a 3 - there is a 5/400 chance of this occurring, there is a 1/8 chance of the roll being an 8, you multiply, so this "helps" you by a fraction of 0.0015625... not very much - but you repeat this process for 4, 5... all the way to 11, and then you add the fraction. In this case, the sum is 0.16125. This sum is then added to 0.6975, resulting in a new to hit chance of 0.85875.

Another way of looking at it is that with advantage, you had 0.3025 chances to *miss*. And in this case, it turns out that hey, in this case @CapnZapp is correct, this is roughly reducing your chance of a miss by half... but this does *not* double your damage, it only goes from 0.6975 to 0.85875 of the "base" damage.

So yeah, this maneuver helps a GWM warrior a fair bit... BUT a warrior who is not using GWM can use that maneuver dice to increase his or her damage instead! I've compared that in my previous posts. The GWM still come out a bit ahead. but it is NOT +10 damage per attack, not even close.

I hope this answers your question.

Thanks for helping me focus my mind on this issue. You are right that exact chances of precision helping with advantage will start to depend on chance to hit unlike how precision works without advantage. However, your example of +4 hit vs a 16ac actually puts us right near the midpoint because we rarely care about trying to use precision attack on very bad misses (Just misses where we miss by up to 4 or 5 typically). Your example uses semi realistic numbers and puts us right in the middle range for "near misses" and as long as we are close to the middle of a d20 with our near misses then precision will only diverge slightly from the non-advantage case. If the enemies ac grows then the value needed for a near miss grows and this will actually increase precision attacks effectiveness. The only time precision will be really less effective is if a near miss occurs when I roll in the lower single digits which is typically pretty unlikely with GWM. All in all I think precision attack actually gets amplified in most natural cases by the GWM feat.

One issue I keep seeing you do is trying to use a precision attack dice any time it might could turn a miss into a hit. Precision attack requires smarter use than that and it's smarter to only use it on misses of so great a magnitude (depending on a few factors). Typically you don't want to use precision attack when you miss by more than 4 or 5. It's a waste in those situations and if you are a high level fighter with 3 or 4 attacks a round you may only want to use it when you miss by 3 or 4 because your more attacks will mean more misses so you can start to actively seek out even "closer misses" due to your greater number of misses due to your greater number of attacks. If you do use precision on any miss where it could help or nearly any miss it could help when you are making 3+ attacks a turn then you will burn through your precision dice too fast and not get to use them the whole day. There's a bit of an optimization strategy you need to follow to maximize the effects.

 

[Yunru]

Daymn, that's a tonne of damage. Although it's far clunkier in it's tiering.

Somehow I feel Elven Accuracy might not make it out of UA.

 

[CapnZapp]

That's fair. I would reply only that I have no problem with feats that provide signature moments of awesome; they should simply be behind some sort of gating for their frequency. (Resource cost, limited situations, or only on certain die rolls, for example.)

When a feat affects a character's bread and butter round-in, round-out combat contribution, that's when I think a more judicious eye towards balance should be applied. Especially when they provide a de-facto steering towards certain concepts, and away from others. I would have much less of a problem with GWM/SS, for example, if they were replaced with a feat called "Power Attack", which gives a -5 to hit for +10 to damage for any weapon attack. It's still not perfect (the offensive boost provided could well be considered a feat tax, and it puts melee attackers without Extra Attack (like rogue) too far behind every other melee attacker), but at least it puts dual-wielders and one-handed weapon users in the same range as two-weapon fighters and archers.

That's my principal concern with balance, to see that player choice of concepts not be constrained by any concern about base utility.

Yep.

Apart from any powergaming concerns, I fail to see how the game becomes better by effectively telling players "You know those axes you though would be cool to wield? Forget about them. You will deal half as much damage than if you choose a greataxe. Why? No reason. It's just that dagger-throwers and spear-chuckers are secretly hated here at WotC HQ, and so we thought it best if some hero concepts were relegated to a decidedly second tier of damage dealing..."

Zorro? Achilles? Drizzt? Legolas? All play D&D the badwrong way. Use a greatweapon or a hand crossbow or GTFO.

I fail to see how anyone can defend the feats. In the featless game, almost every concievable weapons combo works out okay, and the difference between one character concept and the next is never decisive, so you can pretty much pick whatever hero image you want.

Why should feats destroy that?

 

[CapnZapp]

Sure there are a lot of variables, but it's not impossible to come up with a reasonable estimate. And it's really easy once you've come up with the estimate to alter your calculations at will.

Then it's simply a matter of % chance of dropping a foe to zero with a non-critical hit multiplied by the chance of hitting with a non-critical hit.

Your damage increase without doing further math is roughly the chance (it's actually a little lower) of getting a critical hit plus the previous chance you just calculated.

Yes, there are lots of variables but if you aren't going to bother to try then your opinion on the feat isn't really a complete one, is it?

Just grabbing a (semi-)random quote to quickly say I'm aware of the improved crit + cleave discussion, but I have nothing to add (not yet anyway).

 

[CapnZapp]

[MENTION=6689191]Hillsy7[/MENTION] answered that better than what I could've done.

The only thing I would add is that if things works smoothly in a white room, something is wrong. The game's outcome becomes predictable and with predictability, comes boredom and the game becomes quite a lame one indeed.

If a GWM or SS were meant to be able to pull the -5/+10 at all times without problems, it would be no wonder that everybody would do something like that. In fact, you would only see SS and GWM. No need for wizards, clerics or heavy AC fighter types. Just GWM and SS... It would be a boring game indeed.

All white room analysis I see assume, advantage, bless, haste and god's knows what else. But if you remove those, then suddenly the feat isn't that OP. In fact, as a DM you're there to ensure that sometimes, the feat is usable, and other times it is not that great. The barbarian rages and attacks recklessly? The target should dodge! No more advantage. And the target's friends now shoot the barb with their arrows/bolt/cantrips and god knows what... The Paladin is boosted with every spell thinkable? Good, a dispel magic should do the trick for every spells under 4th level. I am the DM, I control the combat and the opponents. I can make sure that all builds will shine at one point or the other.

Yep, white room can help point out some problems. And yes, if a DM allows that kind of boosting these feats can become quite troublesome. On the other hand, the white room can make something quite normal appear quite unbalanced if taken too far. Extremes are just that, extremes...

Not sue what you're saying here.

That even though you have been shown a perfectly regular build that massacres balance using GWM, you still maintain it is okay?

Read my lips: it's not a white room analysis. It's my real, practical game experience.

Read my lips: it doesn't involve any diffuse and arcane soup of bonuses. You don't see "advantage, bless, haste and god's knows what else".

You see (or would have, if you didn't intentionally blind yourself to rational argument):

* A fighter (battlemaster)
* the GWM feat
* advantage

That's it.

 

[Hillsy7]

I will note that I did not compare Precision vs Precision + GWM. My gut feeling is that it would not have helped as much as a damage dice, but I may be wrong.

Just been running some numbers and the output surprised me somewhat……(Disclaimer - this was all done on excel using macros, so none of the calculations will be off, only the base assumptions)

The Precision Featless Vs Precision GWM can be viewed very simply by focusing on Total Damage per short rest

Roughly speaking, SD are a Short rest resource. DPR means nothing long term if your SD use is a slim fraction of non-SD use. So let’s ping out the numbers as per the DMG for a fighter with 3 attacks.
A=Attacks per Round, D=Damage per Attack, H=Hit probability, R=Rounds per combat, C=Combats per Short Rest……

Total Damage per short rest (No SD) = A*D*R*C*H
Total Damage per short Rest (with SD) = (A*D*R*C*H) + (6*D)
[So cancelling out, you can see that the “true” benefit of precision is the ratio of (A*R*C*H) Vs 6 (to be adjusted for likelihood of precision turning a miss to a hit). The more you hit between Short Rests, the less beneficial Precision is……]
Now we know A (3), and we can get R and C from the DMG: (roughly) 5-6 rounds per combat, 2-3 combats per short rest. Therefore A*R*C = 3*2.5*5.5 = ~40. So with 40 dice rolls we can assume each value is rolled twice. Using a target value that’s likely to be somewhere between 4 and 16 we can reasonably (regardless of H) assume you will be using precision to correct for two 1s’, two 2’s and two 3’s. Therefore, we can adjust for likelihood of precision turning a miss to a hit (1+1+0.875+0.875+0.75-0.75). So 5.25 additional D……

So let’s get back to our comparison (Because Advantage is assumed, H is quite high) (Vs AC 19 with +11 Attack bonus)
Fred Featless: H=90%
Gwen Great Weapon Mistress: h=65%
So a rough Comparison with all things being equal and 40 attacks per short rest gives the following Total hits per Short Rest (If Fred doesn’t miss enough to spend SD, I’ve used Riposte to add attacks)
Fred: 3*2.5*5.5*0.9=41.1
Gwen: 3*2.5*5.5*0.65=31.6
Therefore, Gwen gains 5.25 more hits than Fred, or a 17% top up on Damage per Short Rest. Fred only Gains 12.6%. Also you can see that using precision for Fred is much better than just adding SD as damage as turning a close miss to a hit 5.25/6 times with a base damage around 15, is much better than adding a single SD dice on a hit.

So there you go. The benefit of Precision Vs Precision + GWM = Total Damage per Short Rest ratio of 1.167:1.126

However, add it all together (assuming Fred’s Damage = 20 and Gwen = 30) and Gwen is only popping roughly 13% more damage than Fred. This narrows slightly the more Ripostes (Less than 6 misses per short rest) Fred can do.