How does magic armor stack


If I have Body Armor +2, Shield +2, Bracers +2, Helmet +2, and a Ring of Protection +3, do all the magical bonuses get cancelled except for one of them, or can some kinds of items stack those bonuses?

Best Answer

It stacks, depending on the specific items, up to AC -10

First off, AD&D 2e did not yet have the concept of a general rule about limiting bonus stacking. You have to look at each individual magic item to understand how it combines with others (which means, by default there is no rule against them stacking, if the item does not say so, as each item provides the bonus it says). The only limit is that the lowest attainable AC is -10.

In your example

  • Body Armor +2 would add +2 bonus
  • Shield +2 would add another +2,
  • Bracers +2 would add nothing as you wear armor
  • Helmet +2 is an item that does not exist in the rules. If it did (the DM allowed its introduction), it would add +2 bonus
  • Ring of Protection +3, does not add anything as you wear magical armor

That is, this would add up to +4 bonus (with book items), or +6 (with a newly introduced magical helm that improves armor class by +2).

Armor & Shield. The rules for magical armor (p. 181, DMG) say

For each + 1 bonus to armor, regardless of the type of armor, the wearer's Armor Class moves downward (toward AC 2 ... to 1 ... to 0, -1, -2, and so on). A normal shield improves the armor class by one. A magical shield improves Armor Class like magical armor -- toward -1, -2, etc. Note however, that Armor Class can never be improved beyond -10.

So AC bonuses from armor and shield combine. Shield only is a type of armor, too (providing AC 9), so it counts as armor for effects that say they cannot combine with armor.

Helmets. In D&D, including 2e, helmets do not normally count as a separate armor item, they are part of armor (p. 76, PHB).

The equipment list reflects the price of a suit of armor (including an appropriate helmet) made for any normal player character race.

The available magical helms therefore do not change AC class, they provide other effects, like comprehending languages, changing alignment etc. If there was one which modified AC (there isn't), it would stack.

Bracers of Defense say

If armor is actually worn, the bracers have no additional effect, but they do work in conjunction with other magical items of protection

So they would not work while you also wear armor.

Ring of Protection says

The magical properties of a ring of protection are cumulative with all other magical items of protection except as follows:

    1. The ring does not improve Armor Class if magical armor is worn [...]
    1. Multiple rings of protection operating on the same person or in the same area do not combine protection, only one such ring -- the strongest -- functions

So it does not work while you wear magical armor (but it would work on top of mundane armor).