Is there an inexpensive general way to make items forever immune to energy damage?

Question

Some monsters live in environments that deal constant energy damage so that any stuff left nearby is destroyed. Other monsters have special abilities that deal energy damage over a wide area and destroy stuff. In both cases, I want the stuff to survive. Here are some examples:

• A fire weird (Monster Manual II 90-2, 94) lives in a pool of fire that deals fire damage to creatures and objects therein. (Don't worry—the fire weird itself is immune to fire.) The weird's smart enough to own useful gear, and I want to equip it appropriately, but if, while in her pool, she drops something, it'll be destroyed by the fire damage. Likewise, if she doesn't want to carry something, leaving it in the pool will see it destroyed and leaving it outside the pool sees it vulnerable to casual theft.
• A wizard with a penchant for gardening keeps as a servant/pet/guard a greenvise (Monster Manual II 120-1). The greenvise's extraordinary ability death fog deals to each creature and object in a 60-ft. spread 3d8 points of acid damage—no saving throw. (Don't worry—the greenvise itself is immune to acid.) Each use of the greenvise's death fog ability will see the surrounding area decimated… including all the tools the wizard-gardener had been using to prune his greenvise.

When I've encountered this issue while dungeoncrafting, I've longed for a dead simple way to make nearby or carried items immune to energy damage, be it completely or selectively. For example, it seems like overkill to pay 2,000 gp to make the wizard-gardener's Profession (gardener) masterwork tool out of riverine (Stormwrack 128) solely so that it survives the greenvise's deathfog!

Is there a mundane or magical game element that's relatively inexpensive (ideally just double the cost of a normal item or something but certainly under 2,000 gp per lb.!) that can protect forever items from energy damage?

If instead an individualized list of game elements better meets this criteria—like an alchemical coating that prevents sonic damage and a magic item effect that grants an item immunity forever to acid damage and so on—, that kind of list makes an appropriate answer, too.

Answer 1

Blueshine from Magic Item Compendium costs 750 gp, so probably still pricier than you want, and only protects against acid and rusting—but that’s good enough for the greenvise. Also, technically, it’s an armor property. As a flat-cost magic effect, though, it’s fairly trivial to allow on other items—and maybe smaller and simpler items are easier to enhance with blueshine, and so can be cheaper. That’s stretching the rules a bit though.

I am not aware of anything similar for fire damage, or for elemental damage more generally. The expense of blueshine (and the fact that many adventurers consider it a steal at that price) suggests that this is going to be a pretty costly thing, even if other options are found. Riverine, for instance, is certainly pretty popular, despite its enormous price tag.

Answer 2

Magical architecture, rooms, and even entire strongholds can be made immune to energy damage with the Zone of Elemental Immunity from the Stronghold Builders Guidebook (p.86, one energy type, market price: 10,000 gp plus the cost of the stronghold space).

However, people and items inside the space only gain partial immunity.

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The Complete Arcane has rules for creating and protecting spellbooks. Among the enhancements is Waterproofing (immune to water damage or exposure, +1000 gp) and Resistance to Energy, Major (resist 12 vs all energy types, +3000 gp).

This later is the closest thing I can find to an item specific immunity off the top of my head.

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Perhaps these enchantments could be used as a guideline for creating and applying an item only immunity enchantment.

Answer 3

It seems to me that we are talking about relatively low damage here¹ . Even 3d8 caps out at 24 points of damage, which is not that much.

As a result, I would advise looking at Hardness first. It is not necessary to get a Hardness of 24, either, especially for a Wizard's tools; having a Hardness of 20+ simply means that sometimes the object will take a bit of damage, which can be mended.

¹ With the exception of immersion in lava, which is listed as dealing 20d6 of Fire damage per round. That's an average of 70 points of damage per round, with a maximum of 120; I doubt any damage reduction can easily stack up against that sort of damage.

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Metal Items

A quick look at the SRD provides us with the base values:

• Iron has Hardness 10.
• Mithril has Hardness 15 (+500 gp/lb).
• Adamantine has Hardness 20 (probably +1000 gp/lb).

Then, we can apply permanent improvements:

• Races of Stone introduce Dwarvencraft items, which must be mostly made of stone or metals; such items gain +2 Hardness, +10 HP and +2 saves. Armors and Shields only cost +300 gp for being Dwarvencraft.
• Dragon Magazine #358, p. 38, has a full article about new items qualities that an Artisan Craftsman can apply to items. There is a surprising limitation to Weapons or Armors/Shields for many of those qualities, which a DM could reasonably lift; anyway the qualities of interest are:
  • Blood Grove (swords only): +2 Hardness, +100 gp.
  • Folded Metal (metal weapons only): +4 Hardness, +200 gp.
  • Reinforced (all weapons and armors): +5 HP, +200 gp.

If your Wizard has a bit of cash on hand, then they should contract an Artisan Craftsman to make them Dwarvencraft Mithril tools with the Blood Grove and Folded Metal qualities: 500 gp/lb + 600 gp, for a Hardness of 23.

There is a tiny chance (0.2%) of the greenvine dealing 1 point of damage to such a tool; and it can be mended.

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Non-metal items

First of all, those tend to be more fragile:

• Cloth has Hardness 0¹.
• Leather has Hardness 2.
• Wood has Hardness 5.
• Dragonhide has Hardness 10, like Iron.

I also could not find as many options for increasing their hardness; in fact, I could only find the Hardening spell.

The good news is that on non-metal, non-mineral, items, a single casting of Hardening can affect an item of up to 10 cu. ft./CL which should cover an wearable/tool.

Even if the Wizard is not of a high-enough level, a 6th-level spell casting can be bought for 60 gp * CL. At CL 12, that's a mere 720 gp for a +6 Hardness (permanent).

If the DM is willing to let Hardening permanent hardness increment stack:

• Cloth items can have Hardness 24 for 2,880 gp -- 4 castings at CL 12.
• Wood items can have Hardness 23 for 2,160 gp -- 3 castings at CL 12.
• Dragonhide items can have Hardness 22 for 1,440 gp -- 2 castings at CL 12.

Apart from Cloth items, this is likely less than 2,000 gp/lb.

Also, there is only a tiny chance (0.8%) of an item with Hardness 22 to take damage from a 3d8 attack; which can be mended.

¹ And unfortunately I did not find any special Cloth material with greater Hardness; Nightscale and Spidersilk (Underdark) are only listed as Special Armor despite being described as materials, without any hardness.