Bonus and Penalty Stacking

[Caliber]

Simple question ... you have a +1 AC (Morale) and a spell is cast on you giving you a -4 AC (Morale).

Do you now have a -3 AC (Morale), +1 AC (Morale), or -4 AC (Morale)?

In other words, do bonuses and penalties of the same type add together, or does one overwrite the other (as is usually the case with the modifiers of the same type)

 

[Pax]

In the case that yououtline, you have both a +1 AC (morale) and a -4 AC (morale). The net adjustment is -3, yes, but bonusses (and/or penalties) never "merge" into single modifiers.

 

[Saeviomagy]

From what I understand, all penalties stack with each other and with bonuses.

IOW, you've got a -3.

 

[CRGreathouse]

In 3.0, there was no explicit answer, but the books and designers seemed to tacitly assume that the best bonus and worst penalty were added together, so (+4 morale) + (+2 morale) + (-1 morale) + (-10 morale) = (+4 morale) + (-10 morale) = -6.

In 3.5 penalties are supposed to be unnamed, so (+4 morale) + (+2 morale) + (-1) + (-10) = (+4 morale) + (-1) + (-10) = -7.

 

[dcollins]

I believe that it was explicit in 3.0. From the 3.0 SRD:

Bonus Types: Many spells give their subjects bonuses on ability scores, Armor Class, attacks, and other attributes. Each bonus has a type that indicates how the spell grants the bonus. Two bonuses of the same type don't generally stack. With the exception of dodge bonuses, most circumstance bonuses, and bonuses granted by a suit of armor and a shield used in conjunction by a creature, only the better bonus works. The same principle applies to penalties — a character suffering two or more penalties of the same type applies only the worst one.

So, you get the best bonus of a particular type. And you get the worst penalty of a particular type. (In 3.0, where penalties had types.)