Targeting a city from far above

[Journ-O-LST-3]

So, I've accepted an unspoken challenge from my DM(1). It's a ways off but, here's how it plays out:

As a 9th level mage (transmuter) I have access to:
-Teleport
-Shrink item
-Fly
-An Iridescent Spindle Ioun Stone
-Iron (10lb/gp, 16000lb=1600gp*)
(-Scrying)

*(I may need to use a more dense material as I only get 18 cubic feet)

You see where this is going.

Without scrolls I can use 3 Shrink item spells on 3 giant arrow shaped 16000lb ingots of iron and one Fly spell on myself. Then I teleport above my target and send the projectile off to deliver all the damage (just under Fat Man/Little Boy) to my target.

So, is this enough to become a mass driver? Do I need to find some kind of math spell to make it land on my target city/dungeon/Xin-Shalast.

So how would you make it work?

Would using scrolls to summon helper demons (or other outsiders) work to have them guide the projectile?

True Strike might not work since the range increments will be too many.

If I max out Int at 28 can I just make a Knowledge: Math roll to do it?

Since gravity is constant, should I avoid enlarging it and fly it down to within a mile or two before enlarging it and peeling off? (This means I have to use all three at once or have more teleports, also what are the best spells for atmosphereic entry?)

The other option is to try it with Teleport Object and just trial/error where the things land, which is tempting but kind of a little bit into mad wizard raining destruction for laught/SCIENCE and a teensy bit evil).

Also, if it works is it worth it to take the Eldritch Heritage feat for the Divine bloodline so Rodrick the wizard can legitimately call himself "Rod from God?"

(1) He wants me to think well outside the box, and I need an ace to deal with NPCs later on.

[cnetarian]

not going to be much of a mass driver, at least with our universe physics. in terms of our universe, something falling has a terminal velocity, the speed at which the force of air-resistance due to drag = the force of gravity on an object and it does not fall any faster. no idea what the terminal velocity for your iron arrow is but it is very unlikely to be any faster than the 'tallboy' bomb of WWII which was around mach 1. for comparison bullets have to be specially built to be slower than mach 1 for true silenced weapons and a speed on exiting the barrel of twice the speed of sound is not atypical of modern bullets while mass drivers are supposed to operate in the mach 10 range.

note it would still be quite destructive, just not the scale you are talking about. the trick to guiding it is to put spin on it so wind affects it sell, can be done through shaping the fins though. shrunken then expanded instead of expanding on contact with the ground. Since striking the ground ends a shrink spell there is no need to do anything special, although it might be more destructive if it were to embed itself in the ground while shrunken then expanded.

[Chakat Firepaw]

First of all, you aren't going to get anything like the yield you mention. Even if you got them going fast enough to bring the First Law of Space Combat[1] into play, you would only be talking a yield on the order of 10 tonnes[2].

Furthermore, you aren't going to get that kind of speed. Even dropping it from 100km and neglecting air resistance only gets you about 1.4km/s and less than a 2 tonne yield. Once you account for a more sane drop height and air resistance it will be a lot less than that.

All in all, I would start by applying the existing falling objects rule, which works out to 20d6 damage to whatever it hits. Given the shape, I would probably double that with half damage to adjacent squares.

For the target to-hit number: Again, start with the falling objects rule and make the check with something like Know(Math) with scatter based on how much you miss the check by[3]. Perhaps something like 5' for every 1 you miss the check by.

[1] Anything moving at 3km/s packs its own weight in blam.

[2] e.g. Something like the British Grand Slam bomb.

[3] You're talking about a DC that is well over 100 for hitting a given point. You aren't making the check.

[cnetarian]

I'm no so certain you'd have that much a problem with terminal ballistics, put spin on it and it should fall true. I would summon an archon/inevitable or perhaps air elemental to do the design work, one of those should have no problem designing a projectile which would fall straight. If you drop the projectile while no moving and the target is unmoving the only variable keeping it from falling straight is wind, and with spin this should have a minimal effect.

[Arizhel]

1) You will need about 1500' (depending on shape) for your object to reach terminal velocity. Terminal Velocity Calculator
2) The DC of a Perception Check is +1/10'.
3) Therefore, at 1500', your perception DC to spot the target is +150.
4) 28 Wisdom for: +9 Mod +9 Ranks +3 Class Skill +2 Racial, +20 on Die +2 Alertness Feat +3 Familiar = 48.
5) You need an initial DC of -102 or less . . . assuming you have gone above and beyond to max out Perception.
6) Lowest value on chart is -10.

So in addition to the penalties mentioned above, the possibility of spotting the target you want to hit is next to nil. Mind you, if you just want wholesale slaughter, and you just want it to land within a 1500' radius. . .

Second, assuming you want to hit a target: The rules simply don't contemplate what you are asking to do. As such, you are essentially asking to single handedly and spontaneously generate a deep understanding (if not to invent) Trigonometry, Calculus, and Physics simultaneously, in a universe of magic . . . where those disciplines do not seem to exist. . . all within the one year it takes you to reach level 9.

[Journ-O-LST-3]

At 9th level Teleport gets me 900mi outside of the planet (assuming Earth standards) that's about 600ish miles above atmosphere interference. Geosynchronous orbit is around 22000 miles so I'd need Greater Teleport and a while to get back, at this point I suspect I'd be building a wizard's tower in geosynchronous orbit fed by a bottle of air etc.

I think targeting might be doable by trial and error, in that once launched the weapon should hold a geosynchronous trajectory as well. I'm not sure if an air elemental would work for propulsion. I think I remember a spell that magnetizes things, those linked to a permanency spell and a series of magic mouths might get me a rail gun or at least magnetic launching system. Or a much improved Hydraulic Push spell.

Also, how about Telekinesis for building speed, you'd need to extend it a bit but I think there's a good argument that each round in void the 20ft move would build on the one before.

Side thought: once you get to high levels, building a space station becomes pretty easy with permanency on Teleport Circle and Wall of Force as well as some stone shape etc.

Also, this is a city/dungeon strike, in that the target area isn't one square but larger, this isn't a surgical strike but say knocking Xin'shalast over. It becomes less difficult if you bind some kind of spirit thing to the projectile to serve as a guide.

Though I'm guessing it's not doable at 9th level.

[FangDragon]

Terminal velocity is due to air drag. Air drag is a function of speed and cross section area facing the wind (its actually more complex than that due to turbulence but the simplification will give you good intuition).

If your ingot was shaped like a giant dart it would have a much higher terminal velocity than a flatter shape. Ideally you'd drop it from low orbit to gain as much speed as possible but there's only so much potential energy from gravity alone. Sure you'd do a lot of localised damage dropping a few tonnes from low orbit but a proper evil genius needs to think big. Weight helps but the most important factor is speed, due to kinetic energy being 1/2mv^2

So let's consider slingshoting your dart around the sun, you may need several orbits but you should be able to achieve a velocity of 20-30 km/s. If you can arrange for the planet to be in the way of the dart the results should be pretty spectacular in the region where it hits.

You'll need a necklace of adaption to survive in space and some way of steering while in space. I'd suggest using magic to conjure rocks or something and to throw them off at high speed.

[CWheezy]

FangDragon wrote:

Sweet Stuff

This is all great, but the final touch he is missing is a Cowboy hat so you can ride your ingots for the whole trip.

yeehaw

[Peasant]

Personally I think you're setting yourself up for failure by trying to go further outside the box than Karzoug. He is nuts after all, and the combination of insane and magic pretty much gives the GM carte blanche to throw out wild responses of his own. That's not to say it wouldn't be a fun ride. Punch and counterpunch can make for an interesting game.

That aside, let's take your idea even further out of the box and consider the other aspects of Shrink Item. You can give the item a clothlike composition while it is shrunk, which lasts until the spell ends. The term item is as vague as your GM will allow, but the explicit example of a fire and its fuel (probably meant to suggest making a portable campfire) opens the door to fairly liberal interpretation. It even implies that the fire would continue to burn. Incidentally, at no point does it indicate that the spell ends if the material is further worked or subdivided. So...

Oh look, it's a pile of burning coal, about 18 cubic feet worth. Huzzah! One Shrink Item later, it's maybe the size of your fist and can be folded up and put in your pocket (hopefully after using Resist Fire). More importantly it can now be worked as cloth, so it can be spun into thread and woven into say... a net. Fabricate will do that for you in a single round. If we go the conservative route and treat coal as a mineral, Fabricate can still work a volume of 9 cubic feet. If one dimension is only as thick as an eyelash (say 1/100th of an inch) you could fabricate a net roughly 150' square. Unfurl the net at high altitude (you'll need three tiny air elementals to hold the other corners) and simply end the spell. It now jumps up in size by a factor of 16, meaning it's half a mile wide, suddenly rigid and still on fire. It won't hit with nearly the same impact, but it will hit much of the city all at once, starting secondary fires and clogging the streets with strands of burning coal and smoke.

[Journ-O-LST-3]

Nah, Shrink Item is for 16-inch red hot spiky ingots. You get someone to eat the cloth-like form and then explode them.

Or with a larger ball of strong metal. You can use it for mining and building, creating a small hole then putting the small thing in and suddenly expanding it (they do it with ice now).

I'm not after Karzoug in specific, he's just an example of a dude with a city that didn't expect to be blown down to sea level by a PC.

The next idea I'm looking at is Stone to Mud on a large scale to alter wind patterns and dry out regions similarly to using a Decanter of Endless Water to mess with places.

That's it. The decanter in geyser mode produces opposing force. Attach one to the end of my dart at 1500 miles from the surface, let it build speed, ride it long enough to aim for a city and there we go?

[Torquar]

I vaguely remember somebody trying this with a "Planar Cannon". Basic idea is to create a long cylindrical demiplane with double gravity and no atmosphere. Place a portal at the bottom which opens at the top. Drop your weight into the plane and leave it to stew for a few days/weeks/months.

When you want to trigger it just redirect the bottom portal over or at your target.

No idea if it would work, but at least it sounds cool :-).

[Conundrum]

A lot of Big Bang theory physics people on the boards. Physics and its application in real life have very little to do with in game mechanics. Nice brain exercise but really I would treat it as max falling damage for a gargantuan object, which could be at a mere 200 feet as the rules set that as the limit for falling damage.

[Andro]

All rule-talk aside, because what you're trying to do is really holistic and rules simply aren't designed to cover it, here's the problem I have with your approach: You are making assumptions.

Assumption #1: Physics in the make-believe fantasy world where 60' tall giants with human physique do not collapse under their own weight, dragons fly on wings that have nowhere nearly enough lift, and most of the laws of conservation of mass, energy etc are regularly ignored/violated/perverted by both magic and "mundane" effects will, for this particular scenario, function the same way as in our ordered, mundane universe.

Assumption #2: Not only does Assumption #1 hold true, but your character possesses intricate knowledge or innate understanding of the workings of these highly complex laws of physics in the setting where it's unlikely anyone actually penned down Newton's basic F=ma

It's a double-whammy that I witness every now and then, especially in geek-rich gaming groups: Fighter : "I'll mix the sulphur, charcoal and saltpeter and...." Wait a minute. How does your Fighter know what happens when you mix those. And why do you think that what happens on Earth will hold true on Oerth?

So... I probably digressed and didn't provide an actual answer to your question, but if I had to, I'd answer this: Wizards usually study hard looking for ways to bypass or violate mundane laws of physics, not use them for optimal effect. And even if yours was an enlightened Wizard, does he really have the education/knowledge base to reach all the far-fetching conclusions you as the player may be relying on? The way I'd make this work is by RPing the way my character thinks, not McGuyvering my 21st century knowledge of science into a 12th century-esque fantasy setting. :)

[Journ-O-LST-3]

Andro wrote:

It's a double-whammy that I witness every now and then, especially in geek-rich gaming groups: Fighter : "I'll mix the sulphur, charcoal and saltpeter and...." Wait a minute. How does your Fighter know what happens when you mix those. And why do you think that what happens on Earth will hold true on Oerth?

So... I probably digressed and didn't provide an actual answer to your question, but if I had to, I'd answer this: Wizards usually study hard looking for ways to bypass or violate mundane laws of physics, not use them for optimal effect. And even if yours was an enlightened Wizard, does he really have the education/knowledge base to reach all the far-fetching conclusions you as the player may be relying on? The way I'd make this work is by RPing the way my character thinks, not McGuyvering my 21st century knowledge of science into a 12th century-esque fantasy setting. :)

Well, I assume it's considered sub-optimal for a fighter to spend their slim skill points on craft (black powder) but...

Since muskets exist we're looking at something closer to the 1500s but with the added joy of hyper brains representing INT scores over 30 as well as things like Contact Other Plane, think tanks created from Simulacrums making learning quicker.

As for knowing how to, meteors and comets are still things and cause massive landscape damage, the follow up to this is figuring out how to drop these things accurately. Going back to trial and error with dumping them in the atmosphere and seeing where they fall and growing more sophisticated with each attempt.

[Hugo Rune]

You could assume you are targeting a 5 foot square and use the splash weapon mechanic to work out where it lands when you miss. Though this is slightly silly as you would only ever miss by 5 feet. You could propose the same mechanic but scaling up the size of the square for every x (e.g 5) range increments so after x range increments the target square is 10 feet and you miss by 10 feet and so on until you have a scale that you could hit.

To determine the exact square spliyt the square into 4 half size squares and make another to hit roll, using the same to hit score. If you hit the right square was targetted if there's a miss 1d3 to randomly determine the square.

Repeat until if you've missed and then it's random 1d4 until a 5 foot square is hit.

[Journ-O-LST-3]

Well, I think you'd hit a 5 foot square but I don't think you can pick one. Without becoming some kind of mass driver wizard and getting to build a bunch of aim/guide spells that just seems too precise. You can't aim for the bald spot on Karzoug but his tower might be a doable target and if you just want to mess up parts of Xin'shalast that's much easier.