Negative Armor class

[beowulf_gr]

Can you get your AC to be negative through use of Shock Trooper/charging/raging and other similar effects or is there a limit of AC 0 that stops you from using these things if your AC would drop below 0? Also if you can go below 0 what would be the effect?

 

[delericho]

I'm not aware of any combination that would drop it below 0. Nonetheless, if confronted with a combination that would drop it into negatives, I would rule that 0 is a hard cap - that is, it remains at 0 regardless of whatever other modifiers apply.

There are no special consequences for having such a low AC - the maths all work regardless. It's just a pain having to deal with negative numbers.

 

[beowulf_gr]

Let's say you have a lvl 20 Barbarian that isn't wearing any magic items or armor and has a DEX of 10. So far he has an AC of 10. Now let's say he goes into a rage, and charges using the Shock trooper feat with his full BAB thus reducing his AC by (2+2+20=24). Would he go to -14, go to 0 but still get the benefit of 20 points of extra damage or go to 0 but only get the benefit of 6 points of extra dmg?

 

[delericho]

Let's say you have a lvl 20 Barbarian that isn't wearing any magic items or armor and has a DEX of 10. So far he has an AC of 10. Now let's say he goes into a rage, and charges using the Shock trooper feat with his full BAB thus reducing his AC by (2+2+20=24). Would he go to -14, go to 0 but still get the benefit of 20 points of extra damage or go to 0 but only get the benefit of 6 points of extra dmg?

Strictly, by the book, he would end up with a total AC of -14 and could apply the +20 to his damage.

As noted, I wouldn't allow the character to reduce his AC below 0. In the use of Shock Trooper as described, then, he could only get +6 to damage by reducing his AC. (Note, however, that he could still trade off some or all of his BAB for more damage.)

Having said all of that, Shock Trooper isn't allowed in IMC, so take my suggested ruling for what little it's worth.

 

[Ahnehnois]

Shock Trooper is a little sketchy, I'd agree. However, there is no limit on AC. If you can find the penalties, you can drop it as low as you want.

Feel free to make that attack while charging and blinded if you like.

One other rule I might suggest adopting is to remove the auto-success from a 20 and failure from a 1 and either treat them as 40 and -20 or scale them as described in the ELH. Then at least there is some modest disincentive to penalize oneself in this way.

 

[Li Shenron]

IIRC there is no minimum AC in 3e by the book.

Dexterity has a minimum of 0 (e.g. something unable to move) hence min modifier of -5, which can bring base AC down to 5.

But then a size penalty (e.g. colossal -8) can make total AC negative already.

 

[the Jester]

Strictly, by the book, he would end up with a total AC of -14 and could apply the +20 to his damage.

As noted, I wouldn't allow the character to reduce his AC below 0. In the use of Shock Trooper as described, then, he could only get +6 to damage by reducing his AC. (Note, however, that he could still trade off some or all of his BAB for more damage.)

Having said all of that, Shock Trooper isn't allowed in IMC, so take my suggested ruling for what little it's worth.

The issue with this approach is that it's hard to justify the in-game fiction when the barbarian suddenly becomes far more damaging by putting on armor.

 

[amerigoV]

A fun consequence would be every swing is an auto-crit. Not in the rules or anything, but a -10 AC just means you are standing there and taking it. You are not trying to avoid it, you are saying "give me your best shot".

 

[delericho]

The issue with this approach is that it's hard to justify the in-game fiction when the barbarian suddenly becomes far more damaging by putting on armor.

Well, yes. But the in-game fiction is never going to be perfect anyway.