[RPG] really craft an Arrow of Total Destruction by RAW

craftingdnd-5e

Can I craft something like this, and use it, based solely on the RAW?

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(With the obvious difference that, in 5e, it wouldn't “destroy an entire 10-foot radius sphere around the point of impact”, just throw everything in that area into the Astral Plane. But the question is about whether it can be constructed and would operate in 5e, so that's not an important difference.)

Best Answer

RAW, yes.

A Bag of Holding is an uncommon magic item

roughly 2 feet in diameter at the mouth and 4 feet deep. ... The bag weighs 15 pounds, regardless of its contents.

So this couldn't be an arrow for a bow, but you can create a piece of siege ammunition with this recipe, assuming you have the time, ingredients, and gold to craft such an item.

But, really, the only thing here that would need to be crafted is the custom metal cage, which any blacksmith should be able to craft with the appropriate time, materials, and gold. "Crafting" this item would be comparable to "crafting" a backpack that you then store magical items inside of.

Using Siege Equipment

Ballista

a massive crossbow that fires heavy bolts. ... It takes one action to load the weapon, one action to aim it, and one action to fire it.

So this use would not be very beneficial in regular combat, since your opponent would move and thus you might have to aim again (I don't see that in the rules, but a DM may rule that way), but would be in a war setting where you have a large target that doesn't move. The damage of the bolt is 16 (3d10), so foregoing damage for a gate to the Astral Plane might be reasonable.

Crafting

If your DM allows magic item crafting and custom magic items, you may be able to get away with crafting a spear version of this item (after doing the math, it's just too heavy for an arrow).

So our biggest issues are going to be the size and weight of the bag. Luckily, if the Bag of Holding was created by a Celestial, Drow, Elemental Air, or Elf, then the item is half the normal weight (DMG, page 142). That brings us down to 7 pounds. A Bag of Holding, at the regular size, would probably be considered a Small object (DMG, page 247). There's another size of object smaller than that, Tiny (DMG, page 247). If a fully customizable magic item is allowed, you may be able to craft a Tiny Elven Bag of Holding, which would be about the size of a bottle or lock, and potentially \$\frac{1}{8}\$ of the weight (assuming that a Tiny Bag is \$\frac{1}{4}\$ the weight of a regular Bag), bringing us down to a little under 2 pounds. I don't think we can get much smaller or lighter than that based on the PHB and DMG.

While a Bag of Holding is Uncommon, a Tiny Elven Bag of Holding might be Rare, or even Very Rare. We'll just assume it's Rare, though. Per Crafting Magic Items in the DMG, that would make its creation cost 5,000 gp. However, you can make progress in creating a magic item in 25 gp increments instead of just 5.

A Portable Hole is a rare item, can be folded to the size of a handkerchief, so we can probably just consider its weight negligible for our purposes.

For our cage, we'll look at the bucket, which would probably be close enough to consider it one for pricing and weight purposes, which is 5 cp and 2 pounds.

According to the Adventuring Gear chart in the PHB, a spear is 3 pounds and is worth 1 gp. Per Crafting of Downtime Activities in PHB, you can craft up to 5 gp of nonmagical objects a day.

So we're at 10,001.05 gp, and 402 days to create every component and affix them together. Coming in at 4 pounds for the head of the spear, and a maximum of 4 pounds for the shaft (looking at the Staff Arcane Focus as a maximum). This would probably make for a Heavy Spear of Total Destruction, with a one-time use.