Pathfinder Weapon of Mass Destruction


Rules Questions


The heaviest known Naturally occurring element is Osmium. It weighs in at 22.59g/cm^3. So one cubic meter of Osmium would weigh ~22500 kg. Or roughly 51,000 lbs. So if a Mage were to fly up into the Upper Atmosphere with Life Bubble on, use Major Creation to create 9 cubic feet of Osmium, and let it fall back to Earth; what would be the result? Anyone out there with a physics background want to help me out?


Aiming that sounds like a problem. Even as dense as it is, there's plenty of time for winds to act on your 2-and-a-bit foot diameter sphere. It weighs a bit under 6 metric tons if I haven't dropped a decimal place somewhere, and if you're dropping it 10 000 m that means ~600 megajoules of energy. A little of the surface might melt briefly and it should penetrate a fair way into the ground.

Edit: this is more like a big cannon shell than a WMD. Osmium is slightly poisonous but there is no reason to believe any significant amount will burn or vapourise.


1 person marked this as a favorite.

Since the duration would be at best 1 round/level it may disappear before it hits. That is if it can be created at all. The spell specifies that Cold Iron items cannot be created, so it may not be possible to use it as you think. Even if it can the material component is a tiny piece of matter of the same sort you intend to create. That would imply that to create a cube of Osmium you require a small sample of it.


2 people marked this as a favorite.

First up, let's assume our wizard knows at least something about aerodynamics and makes a cone of the material. Specifically, a cone with 1/3 the volume of a cylinder with equal diameter and height (there are more efficient shapes, but calculating their cross-section area becomes a pain). We get an area of 0.77m^2, which some calculator tells me gives a terminal velocity of 966.375 m/s. It takes 98.5 s or 16.4 rounds of 1g frictionless freefall to reach this speed, during which time the cone has fallen slightly under half the 100km google tells me is the height of the atmosphere. We hit the ground 54s (9 rounds) later, for a total time of about 26 rounds. Extend Spell is recommended.

We have a kinetic energy of 5.38 GJ (1.29 tons of TNT, according to some internet converter), which will be imparted to the surrounding terrain primarily as heat and fast-moving debris. If it matters, a high-speed approximation gives our cone about an 8m penetration into granite (provided it survives impact, which it might not).


And most of the energy of this projectile is directed straight downwards, not outwards. Depending on what it hits, you might just end up with a deep hole.

Looking into wikipedia's list of largest non-nuclear explosions. If it imparts enough energy to what it hits to act as an explosion, it would probably destroy a large structure, and shatter windows in a wide area.

Effective, but you're likely to find better uses for a fifth level spell slot.


The thing about just making a hole is that, using the 8m hole into granite as an example, that's still 6 cubic meters of rock that needs to go somewhere. It can't go straight up because the projectile is in the way, so is pushed outwards into the surrounding material. which then needs to go somewhere, etc, etc.

And it's a lot more than one 5th level slot. It also costs the rescources to breathe at the edge of space, getting to the edge of space (I would recommend teleporting, it's 9 hours of flying straight up at 60 feet per round), and staying up there. (Plus possibly a way to get back down safely, but it isn't fully necessary) You can't see your target due to a -32808 distance penalty to perception), and it's over 12 minutes from when you start casting major creation to when the bullet hits the ground.


There's definitely an explosion. It's just that the explosion is not equal to setting off 1.29 tons of TNT in the same spot. The same amount of energy is there, it's just doing different things.

My point is, this is a situationally useful thing to do that overall, won't do that much compared to what else you can use your character to do.


1 person marked this as a favorite.

Thanks for the insight, everyone!


1 person marked this as a favorite.
The Sideromancer wrote:
You can't see your target due to a -32808 distance penalty to perception

Heh.

But there’s a solution to that.


3 people marked this as a favorite.

Both it and the planet would take 20d6 points of damage?

No need to murder catgirls to resolve this one.


A cone is most stable descending when the flat base is pointed towards the ground BTW; there's a reason that returning spacecraft are mostly shaped like that. Sure the drag's higher but mass at the bottom is more stable. If you start with the cone pointed the opposite way it will tumble as soon as a crosswind strikes. This is why I suggest a simple sphere, tumbling isn't so relevant then.


1 person marked this as a favorite.

I went with the cone tip-first since it was the most aerodynamic shape that had dimensions that were easy to calculate. The optimal shape usually has a frontal center of mass. Clearly, we need to calculate the best way to optimize weight and stability within our set volume


If we cast true strike afore dropping the thing we've little cause to worry of aerodynamism.

blaphers wrote:
No need to murder catgirls to resolve this one.

Blasphemies! Kill all the catgirls!


1 person marked this as a favorite.

Dunno AA, we're taking all the range increments here, not just 10. Early ICBMs had targeting errors of multiple kilometres. True strike might not be enough. Maybe give it some control surfaces and a suicidal AI?

Liberty's Edge

1 person marked this as a favorite.
Pathfinder Battles Case Subscriber; Pathfinder Companion, Maps, Pawns Subscriber; Pathfinder Roleplaying Game Superscriber; Starfinder Charter Superscriber

1: Spell duration shouldn't really be a problem once you realize there is no need to go that high up... terminal velocity can be reached from lower altitudes.

2: The optimum shape can be seen in the form which liquids (e.g. rain / tear drops) assume when falling... so the inverted cone idea is pretty close.

3: Casting Shrink Item on an object and then reversing it from high altitude would give you double the volume of material from a lower level spell.

You could also easily prepare a couple dozen such items and then scatter them over an area.

So yes, magic breaks things.


1 person marked this as a favorite.
blahpers wrote:

Both it and the planet would take 20d6 points of damage?

No need to murder catgirls to resolve this one.

As a small, dense object dropped from more than 150 feet up, it would do 4d6 points of damage (save for half).


I'd have to refer you to my profile for an answer, but given your description off the cuff I'd say nothing would happen at the ground but you'd see a pretty light in the sky a few days to a few weeks later (should the created material last that long).


Azothath wrote:
I'd have to refer you to my profile for an answer, but given your description off the cuff I'd say nothing would happen at the ground but you'd see a pretty light in the sky a few days to a few weeks later (should the created material last that long).

Given your reference to the content of your profile why do you respond to posts in the "Rules Questions" forum?


I suggest shaping it as a conic drill, so it can better pierce the havens on its way to the ground.


1 person marked this as a favorite.

You want a WMD, create the same amount of Dimethylmercury and drop it.

With enough altitude it should fall as a nice gentle mist.


1 person marked this as a favorite.

If we're abusing chemistry, I would recommend C2N14 except it would explode before hitting the ground. In fact, it would explode as soon as you finished casting a spell that makes it. Possibly before. I guess you could crank up abjurations and handle it personally.

Sovereign Court

Reverse Gravity cast a "merely" 10th level (did the numbers for PF 2.0, with a fixed 1 minute duration at 9.8 m/s^2) will launch something just **OVER 9000!!** feet in the air.

When the spell ends, it will fall approximately 2743m.

Assuming 155 pounds (70kg), the average weight of Dwarf male, the energy on impact would 1,881,698J, or 1,387,900 ft-lb in Freedom units.

Of course, this means that Reverse Gravity is a death spell when used outdoors, but that is not a lot of energy.

While this is not really that much energy (1kg of TNT is 4.8 megajoules), despite the big numbers, it can be used to set off explosives (with a Dwarf!) and as a time delay to cast Teleport to GTFO.


Sure if you ignore the area of effect and this partin the first paragraph of the description
"If an object or creature reaches the top of the area without striking anything, it remains there, oscillating slightly, until the spell ends. At the end of the spell duration, affected objects and creatures fall downward."


1 person marked this as a favorite.

1. Ready an action to dismiss reverse gravity just before a creature reaches the top of the area.
2. Friend bull-rushes foe into the area.
3. Foe falls upward.
4. Readied action goes off. Spell is dismissed. Momentum does its thing.
5. Everyone cries because by the time you have that spell, fall damage is a drop (ha!) in the bucket.


I don't know if this is possible in Goloion, but suppose you had a horizontal portal facing up and it's pair some distance above pointing down, and this was all in a vacuum. Now suppose you drop a weight perfectly aligned with the portals with no sideways velocity, it will fall forever, accelerating asymptomatically towards C. If the portal ever failed for some reason the results would be spectacular.


If the ring gates or whatever were misaligned at all (and you can't really align them much better than human vision will allow, even with Goggles of Minute Seeing) then eventually the weight will hit the edge of the portal and either head off at an angle or break the portal. Probably well before you get fun effects.


I see a lot of un-cited sources here. What's all this about terminal velocity and aerodynamics? I can't find it in any of the rule books.


If we're bringing momentum into the mix, you can't beat the old chain-of-peasants-passing-a-rock trick.


There's no guarantee that the final state of the object has the same velocity as the average needed to get to where it is. We would need a lot of details on what exactly goes on with the peasants themselves.

Community / Forums / Pathfinder / Pathfinder First Edition / Rules Questions / Pathfinder Weapon of Mass Destruction All Messageboards

Want to post a reply? Sign in.