Question about negative AC

[beowulf_gr]

Hello all. Just a quick question. Is there a limit to how much you can reduce your AC through using feats etc? Meaning for example Shock Trooper to take from AC and add to Dmg along with a stance and Barbarian rage. Can it go below 0?

[weckar]

Ummm, you are aware that in this edition of D&D a higher AC is better right? They changed that.

[Heliomance]

Yes, it can go below 0. You can add Inspire Recklessness from the Warchanter, too, to junk even more AC. Also Karmic Strike and Robilar's Gambit. There used to be a build around these parts that did so, and had a negative AC. Unfortunately, it no longer seems to exist.

[beowulf_gr]

Ummm, you are aware that in this edition of D&D a higher AC is better right? They changed that.

I am yes. My character doesn't care about AC at all. He just wants to hit things. Hard. :smalltongue:


Yes, it can go below 0

If you can think of any place in any book to support that so I can throw it at my DM's face you will have made me a happy Ogre.

[Heliomance]

If you can think of any place in any book to support that so I can throw it at my DM's face you will have made me a happy Ogre.

None of the effects that let you junk AC prohibit you from going below 0. There's nothing magical about the number 0 that would stop you. All it means is that a prone level 1 commoner wielding a weapon he's not proficient with could still hit you.

After all, if it's possible to have negative attack bonuses, why not negative AC?

[SinsI]

I think only magic can make your AC negative. In essence, it'd have to be some kind of curse that pulls attacks that are going way off course to aim straight at you.

[Lanaya]

The broad side of a barn has -3 AC by default: -8 for size and -5 for having effectively 0 Dex. It doesn't take any sort of magic, just means that you can be a blindfolded, drunk and crippled commoner and still have a decent chance of hitting it.

[beowulf_gr]

My concern is mainly that all effects that work the same way but by reducing BAB like Power attack have a maximum equal to BAB. You could read that as BAB cannot be negative and extrapolate the same rule for AC. Also it kind of feels wrong and nonsensical

[Eldariel]

My concern is mainly that all effects that work the same way but by reducing BAB like Power attack have a maximum equal to BAB. You could read that as BAB cannot be negative and extrapolate the same rule for AC. Also it kind of feels wrong and nonsensical

It is weird, but e.g. Shock Trooper can easily drop your AC far into negatives. Yes, you'll be easier to hit than a dead man; you're actively running into their blades. That's about the most logical explanation.

[TypoNinja]

It is weird, but e.g. Shock Trooper can easily drop your AC far into negatives. Yes, you'll be easier to hit than a dead man; you're actively running into their blades. That's about the most logical explanation.

Barbarian Rage in a nutshell isnt it? "I'd rather take you with me than slow down to block an incoming attack."

[Firechanter]

Shock Trooper can lower your AC by up to -20; subtract another -2 for Rage and another -2 for Charge, and you'll be in the negatives even with some magical gear.
Better substitute your AC with an Attack roll, as per Wall of Blades. ;)

[KillianHawkeye]

There is no rule that says AC cannot be negative. Therefore, it can be.

[Eldariel]

Barbarian Rage in a nutshell isnt it? "I'd rather take you with me than slow down to block an incoming attack."

More or less. I always thought it more along the lines of "Smash you so hard you don't hit back" :smalltongue:

[Zombimode]

My concern is mainly that all effects that work the same way but by reducing BAB like Power attack have a maximum equal to BAB. You could read that as BAB cannot be negative and extrapolate the same rule for AC. Also it kind of feels wrong and nonsensical

Your BAB cannot be negative. Your Attack Bonus however, can. AC is on the same level as Attack Bonus, since it is those two values that are compared to each other during an attack, not your BAB.

Also, why does it feel "nonsensical" to you? AC is just a number that represents how easy/hard it is to make a successful attack against you. The semantics of AC are entirely coded in the attack roll formula. Its Attack Bonus + d20 >= AC, meaning the smaller AC is, the more likely it is for the attack to be successful. Since -x is smaller then x, a negative AC has indeed a very clear meaning.

[beowulf_gr]

Since -x is smaller then x, a negative AC has indeed a very clear meaning.

I get that in terms of the maths/mechanics. But translating the concept of AC to real world equivalent stuff I understand it like this. Armor/shield bonus etc is protective wear and pretty clear, dodge and deflection bonus is also obvious, natural armor as is natural armor. Size modifier makes perfect physical sense in that the bigger sth is the easier it is to hit it. DEX bonus represents your own skill to avoid being hit and is the active element of AC. Now granted if all these were 0 and you were really big you would go negative but then there is the 10+ for everybody which means basically that a paralysed naked, non magically enhanced human has an AC of 5 (10 - 5 DEX).
Again I understand that the 10 comes for mechanical reasons mostly as the floor function of the average roll of a d20 (10.5) but still it does make sure that normally you cannot go below 0.

All this is just things I can think of that my DM would argue in order not to allow me to use Shock Trooper and a homebrew version of Reckless offensive that limits the reduction only by the BAB, in order for him to avoid having a crazy Ogre dealing 1000 dmg per round

[Segev]

If we ignore NAC, the ground has a negative infinite AC.

After all, have you ever heard of anybody missing the ground who wasn't trying very, very hard to do so?

[ZamielVanWeber]

After all, have you ever heard of anybody missing the ground who wasn't trying very, very hard to do so?

I tried to toss something on the ground in front of a person and smashed them in the head instead... So yes.

[Chronos]

Arthur Dent.

[Barstro]

After all, have you ever heard of anybody missing the ground who wasn't trying very, very hard to do so?

I seem to recall Arthur Dent doing it by accident the first time.

EDIT; Damn ninjas.

Back on topic;
I'd rule that AC cannot drop below 0 based on the logic stated by others above. If a player could provide a good reason to become negative, I might allow it ("Sheathing the Sword" to make an attack, ala Lan Mandragoran). Using a homebrew is NOT a good reason, IMHO. Homebrew (everything, really; but homebrew especially) is subject to DM approval.

[Segev]

I tried to toss something on the ground in front of a person and smashed them in the head instead... So yes.Even with a negative AC, I guess you still miss on a nat "1," then!


Arthur Dent.
Oh no. Not again.

[Barstro]

I tried to toss something on the ground in front of a person and smashed them in the head instead... So yes.

That was you rolling a "1", not your former friend having AC-3.:smalltongue:

[Zombimode]

I'd rule that AC cannot drop below 0 based on the logic stated by others above.

So far, no reasoning was given in this thread for why AC can't drop below 0, but plenty of reasonings for the opposite. So whats your explanation to cap AC at 0?

[Barstro]

Beowulf_gr's quote itself,


Again I understand that the 10 comes for mechanical reasons mostly as the floor function of the average roll of a d20 (10.5) but still it does make sure that normally you cannot go below 0.

I also guess I was reading into some things that others said, as opposed to having an actual quote; how can one suddenly become easier to hit than a person standing perfectly still without armor? If doing nothing to protect yourself is a "5", then you have to be very reckless to drop lower than "5". One would have to try to get hit to be five below that ("0").

To that same end, I am a believer that the die only matters when something is not guaranteed. One does not roll an acrobatics check to get out of bed and walk downstairs, and one does not roll to shot a mundane arrow from the ground to another dimension. If one's AC becomes 0 simply because he his trying to put himself in harm's way, I'd say the attacks automatically hit. AC of a negative doesn't make matters worse than a sure thing.

Again, we are talking a homebrew situation. This is for a player and DM to negotiate the rules.

EDIT; to make it clear, I have no problem with AC going negative and would allow the OP's build, but every swing at hit connects since he is furiously hitting someone's fist with his face. RAI, I don't think such a situation was considered and isn't really covered by the written rules. RAW, it doesn't matter; he's going to get hit a lot.

[ZamielVanWeber]

That was you rolling a "1", not your former friend having AC-3.:smalltongue:

I have atrocious depth perception, so that was houseruled range increment issues there.

[Zombimode]

I also guess I was reading into some things that others said, as opposed to having an actual quote; how can one suddenly become easier to hit than a person standing perfectly still without armor? If doing nothing to protect yourself is a "5", then you have to be very reckless to drop lower than "5". One would have to try to get hit to be five below that ("0").

That could be a good point if the premise would actually be true. But a creature that does absolutely nothing to defend itself doesn't has an AC of 5. It is, per RAW, considered helpless. That means it Dex is treated as 0 and melee attack receive an additional +4 against the helpless target. So you could say it has an effective AC of 1 vs. melee. But being helpless makes one eligible for coup-de-grace which hits automatically.

This is a different situation than the naked Raging Reckless Charging Shocktrooper'ing Barbarian. In both cases a hit is very likely but under no circumstances the Barabarian will receive a guaranteed hit.

Also, you could equally envision the other extreme: a very low to-hit. Lets start with a weak (base Str 8) venerable (Str -6) human commoner level 1 who is prone, shaken and cursed by a hexblade, fighting with an oversized weapon he is not proficient with, fighting defensively.
Thats an impressive 0 (Bab) - 4 (Str) - 4 (prone) - 2 (shaken) - 2 (curse) - 4 (oversized weapon) - 4 (non-proficiency) - 4 (fighting defensively) = -24 on the attack roll. Now it is very important if the above Barbarian has an AC of 0 or -20.

Now those are extremes. But they illustrate that there are potentially situations where those negative numbers matter. Houseruling them away is superfluous at best and harmful at worst. Under most "normal" condition, negative AC does not come up, so houseruling is not needed. But in extreme conditions, they can actually be important and houseruling them away can be harmful.

[KillianHawkeye]

Also, you could equally envision the other extreme: a very low to-hit. Lets start with a weak (base Str 8) venerable (Str -6) human commoner level 1 who is prone, shaken and cursed by a hexblade, fighting with an oversized weapon he is not proficient with, fighting defensively.
Thats an impressive 0 (Bab) - 4 (Str) - 4 (prone) - 2 (shaken) - 2 (curse) - 4 (oversized weapon) - 4 (non-proficiency) - 4 (fighting defensively) = -24 on the attack roll. Now it is very important if the above Barbarian has an AC of 0 or -20.

As a less extreme example, let's take a level 1 Ranger with 18 Dexterity. His normal attack bonus with a bow will be +5 (1 for BAB and 4 for Dex). It only takes four range increments to drop his attack to negatives. If firing at his target from the maximum effective range of his weapon, it drops to -13 to hit, meaning that he will miss the broad side of a barn about as often as he hits it.

[Segev]

For the raging ball of reckless fury that is our -24 AC shocktrooper berserker, one could justify the "easier to hit than a guy standing still" thing by envisioning his gyrations and motions being so fast and furious that he is practically a larger target.

Where one might normally justify somebody dodging more readily by moving so fast the attacker cannot tell where he is, in this case it's more like why they say the Flash actually gets wetter in the rain than would a normal person: he's moving through that many more rain drops, horizontally, than is somebody who is mostly being hit by vertical-fall.

So our -24 AC dude is actually moving IN to blows. Not because he's seeking them out, but because he's moving so much and so fast that it's harder to MISS him. He'll be in your weapon's arc of motion at some point in his gyrations!

[Grod_The_Giant]

All this is just things I can think of that my DM would argue in order not to allow me to use Shock Trooper and a homebrew version of Reckless offensive that limits the reduction only by the BAB, in order for him to avoid having a crazy Ogre dealing 1000 dmg per round
As a general rule, if you're worried that a GM is going to ban your character because of optimization shenanigans, you're going to need to tone it down, no matter how RAW-accurate the build may be.

(Also, that homebrew feat seems like the weakest link in the build here, not "negative AC")