9th level Wizard + 10,500 GP = Crafting a Weapon of Mass Destruction?

[M. Breqs]

So my gaming group is in a storyline where we are adventuring to gather a powerful weapon to defeat a massive, dense army. The GM sees us getting to level 20 for an epic battle at the end... But I think we've found a short-cut that requires a 9th level Wizard and a minimum of 10,500 gp (more if you want to be safe about it).

Constructing the Weapon of Mass Destruction

1. Craft a reservoir or tank. Fill it with 409,600 gallons of water (that's 1,550,504 litres, about 60% of an olympic swimming pool. Or 3,418,276 pounds of water.)

2. Cast Shrink Item, and permanency (7,500 gp)

3. Take the now 100 gallons of water. Apply dust of dryness (850 gp to buy), creating a single pellet.

4. Craft a small hollow spherical adamantine object with a tiny, pellet sized hole in it (value would vary, from 60 gp for an arrowhead to say 3000 gp for something the size of a handheld weapon).

5. Place the pellet in the sphere.

6. Seal the hole in the sphere with sovereign glue (2400 gp to buy)

OPTION 1: Place the sphere in an extradimensional space (such as a bag of holding, 1250 gp to craft) until ready to use... After all, If this goes off accidentally, you wouldn't want this in the same area or plane of existence as your party.

OPTION 2: Heat the tank of water to boiling before casting shrink item. Yay for scalding damage!

OPTION 3: Create multiple pellets and put them in the same adamantine sphere for a corresponding increase in destruction.

OPTION 4: Adamantine really isn't necessary, but would create some very deadly fragmentation. It also protects the pellet(s) pretty well, prior to detonating.

Using the Weapon of Mass Destruction

When you want to detonate the weapon, greater dispel magic, disjunction, or anti-magic field should do the trick. The complicating factor is detonating the weapon from a safe distance.

A set of ring gates would work (really expensive at 40,000 gp to buy), to cast the spell from a safe distance... So would a contingency teleport (1,500 gp focus, must be 11th level caster) in order to get to a safe distance. An arcane archer with a CL of 11 and Imbue Arrow could imbue said arrow with Anti-Magic Field to activate when it strikes the target.

Questions

So, some questions.

- What do you think would be the destructive power of 1.5 million pounds instantaneously bursting out of a sealed adamantine sphere (or even many times that mass if you used multiple pellets)?

- What would happen to a walled fortress with this detonated inside it? I would figure the walls would collapse... What about the effect to an assembled army in the field?

- What would the safe distance be for something like this?

- Any other ways to safely detonate the weapon?

Anyways, thanks for your thoughts all.

Cheers!

[M. Breqs]

Some thoughts...

I would assume that the moment the magic is dispelled, the explosive velocity or the water constrained in the adamantine sphere would be instantaneous. Note that that instantaneous is infinitely more explosive than anything on this chart:

http://en.wikipedia.org/wiki/Table_of_explosive_detonation_velocities
Is that reasonable?

Given that a pellet would expand from a tiny (say a 5mm diameter sphere?) to an olympic swimming pool, the volume of expansion is vastly greater than any conventional, real-world explosive.

[loimprevisto]

Quote:

Shrink Item

...
Target one touched object of up to 2 cu. ft./level

Aside from rule 0 issues, the spell shrink item would not be able to affect an 400k gallons of water.

[alientude]

M. Breqs wrote:

1. Craft a reservoir or tank. Fill it with 409,600 gallons of water (that's 1,550,504 litres, about 60% of an olympic swimming pool. Or 3,418,276 pounds of water.)

1 cubic foot can hold 7.48051948 gallons. To fit 409,600 gallons, your tank would have to be 54,756 (rounded) cubic feet, or a 37' cube. That much material would significantly increase the cost.

Quote:

2. Cast Shrink Item, and permanency (7,500 gp)

Shrink Item works on an object 2 cu feet per level. So you'd only need to be a 27,378th level caster to shrink this tank. Also, if you could conceivably shrink the tank, it's debatable whether or not the water inside it would shrink also.

[Lincoln Hills]

Congratulations on your creativity, but I doubt the GM would appreciate such an ending to the campaign... assuming the GM doesn't have an even dirtier surprise planned in return, such as having you blow your megaweapon on what turns out to be a set of mirage arcana images of a bivouacked army. Also, why are you so anxious to end your campaign prematurely? Got a bus to catch?

[AvalonXQ]

The first problem, already pointed out, is that you can't shrink that much water with a "shrink item" enchantment.

The second problem is that the container of water, when shrunk, is not 100 gallons of water. It's still 409,600 gallons of water, just miniaturized. The dust of dryness doesn't affect that much water; it only affects 100 gallons worth.

The third problem is that, once completely closed up in the adamantine sphere, you no longer have line of effect to the pellet, and so there's no way to target it with a dispel nor would it be affected by the AMF.

The fourth problem is that dispelling or suppressing a pellet from dust of dryness will result in a non-magical pellet, not the sudden production of water. So a sudden AMF or dispel magic wouldn't do anything.

The fifth problem is that, as explained in other spell descriptions, size-changing effects don't generally have explosive consequences. This isn't physics here; it's magic. There's no reason to believe that this situation would break the general rules and cause explosive pressure (water growing outwards) rather than just instantaneous, magical change (a pellet disappearing and water appearing in its place).

It's a neat idea, but I just don't think things work the way you describe.

[M. Breqs]

loimprevisto, alientude;
Good catch, thanks guys, I missed that. Sort of renders this course of action really impractical, huh?

;)

Could still be done with multiple castings of shrink item over time, but the permanency would be cost prohibitive. A bunch of 5th level wizards or 6th level sorcerers could pull it off over time, but again - not practical at all.

As for the container, shape stone (or a lyre of building, or a dozen dwarves with strong backs and a few) could easily hollow out a reservoir on the surface of any exposed rock. After all, the water needs to shrink, nothing else...

Lincoln Hills;
Oh, we're not trying to short-cut the game at all. It's more of a mental exercise, just to see if it could work. The GM is in on our discussion, so it's all above-board. He mentioned the "Rule Zero" thing. And yes, it would be a one-shot deal, so we wouldn't want to waste it. My character is a divination specialist though, so we'd go out of our way to minimize the chance for error...

AvalonXQ;
Hadn't thought of whether or not it's actually 100 gallons or 400K gallons still for purposes of the dust of dryness.

As for line of effect, AMF doesn't need it, so that's still one option.

Anyways, the "no damage from size-changing" precedent, while not explicit for something like that, is the deal-killer though. I had forgotten that.

[AvalonXQ]

AMF is still an emination, and so you still need line of effect. A completely enclosed creature or object would not be affected.

But, again, a pellet in an AMF would not produce water; it would just sit there.