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A Sword Without a Hilt: A Song of Ice and Fire/D&D 3.5 Crossover

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Azel said:
Listen up you primitive screw heads! This is my

Magitek Railgun
Warning: Contains Math, Mad Science and Hubris, Keep Away From Children Under Level 3

1. Physics
First thing first, we need to find out how much 1 point of lightning damage is in real world units. To find this out, we use 5 feet long iron pole with a diameter of 1 inch.
π * ( 0.5 in )² = 0.79 in²
0.79 in² * 5 ft = 776.7468 cm³
776.7468 cm³ * 7.847 g / cm³ (densitiy of iron) = 6.1161 kg

According to this, it will need roughly 550 kw/h of electricity to melt a ton of raw iron.
550 kw/h * 0.0061161 = 3.3639 kw/h
This would completely liquefy our iron pole.

Said pole has Hardness 10 and 30 Hitpoints, for a total of 40 electricity damage to completely destroy it. D&D says that electricity and fire usually do half damage against objects, but halving electricity damage to iron seems just as sane as halving that of fire against wood.

Let's now eliminate the time dimension by converting to MegaJoule and get the final power.
1 kw/h = 3.6 MJ
3.3639 kw/h * 3.6 = 12.11 MJ
12.11 MJ / 40 ED = 302.75 kJ / ED

Since this damage is done entirely by Joule Heating, we can now calculate the actual current.
Energy = Volt * Ampere = Volt² / Resistance
Resistance = Resistivity * Length / Crosssection
Resistivity of iron = 9.71×10−8​

Therefore:
9.71×10−8​ * 1.524 m (length in a sane unit) / 5.096764x10-4​ m² = 2.90342x10-4​ Ohm
SqrRoot( 302.75 kJ * 2.90342x10-4​ Ohm ) = 296.4811 V
302.75 kJ / 296.4811 V = 1.0211 A

Given that the energy scales linearly with every ED and assuming that the voltage of a electricity attack remains static, we can assume that Ampere grow linearly with ED, giving us:
A(x) = A(1) * x

Now let's calculate what we get for our buck.

Normally a railgun has the problem with the very low inductivity of the the rails requiring tremendous amounts of energy to launch a projectile. This is a simple result of no coiled wire being able to withstand the forces of the launch. The projectile would destroy the rail before it has even reached the end of the barrel.

However, this isn't Real Life, but D&D and we are cheating bastards.
By making the rails into Adamantine coils which are fixed into place with a Wall of Force, we can get a optimized setup that can easily withstand the forces of firing. While regular Wall of Force seems not up to the task, Riverine is proof that the effect can be used to make nigh indestructible materials. Pricey, but worth it.
We thus use Adamantine wire around a iron core and encase everything in a Wall of Force effect, except for thin Adamantine contacts in the barrel, which allow the projectile to close the circuit. To make the whole thing even sturdier, we liberally apply Harden to the setup.

The inductivity of a coil is given by:
L = µ0​ * µ * Coils² * Crosssection / Length
We assume an average of 5000 coils per meter of the coil, a crossection of 25 cm² and a length of one meter. Due to the length of the coil changing as the projectile moves through it, the rail isn't uniform if we want a constant inductivity, which is preferable for a uniform acceleration.
L = (4πx10-7​) * 5000 * 5000² * 0.0025 m² / 1m
L = 392.6991 H

I won't go into too much detail of railgun design, since my browser history is already questionable enough, but Wikipedia supplies a simple formula:
F = L * I² / 2

Which gives us:
(1.0211 A)^2 * ED^2 * 392.6991 H / 2 = F
F = ED² * 204.7229 N / ED²

The final energy of the projectile is thus given by:
ED² * 204.7229 N / ED² * Barrel Length = x Joule

2. Costs
First, the rails. We assume that the weight of the coils per cm³ is the same as iron.
π * ( 2.5 cm )² = 19.634954 cm²
19.634954 cm² * 100 cm = 1963.4954 cm³
1963.4954 cm³ * 7.847 g / cm³ (densitiy of iron) = 15.407,5485 kg = ~34 pounds

Since the most weight comes actually from the iron core, not the Adamantine-Riverine bastardization around it, we will assume that we only have to pay for 20 pounds of material, the rest being dirt cheap iron. A chain shirt weighs 40 pounds, so we will assume that the material value of it will cover the cost for two parallel rails per meter of their length.
16,000 GP (Riverine) + 10,000 GP (Adamantine) = 26,000 GP per meter = 5,200 IM per meter

Turns out WMDs don't come cheap and we haven't even started on spells.

We can safely ignore Harden, since that is only cast at the rails once and doesn't need to be enchanted into the gun itself. However, we do need spellwork to make sure the gun doesn't break down after a few shots due to overheating or wear. The latter is covered for the rails themselves, but unless we want to shell out even more money to build the whole carriage out of hideously expensive materials, it's better to add Make Whole.
Make Whole: 1800 GP (Command Activated) * 2 (Spell Level) * 3 (Caster Level) = 10,800 GP = 1,080 IM -> 810 IM (Lya Price)

For overheating, we will use Chill Metal, which explicitly is capable of negating heat damage.
Chill Metal: 1800 GP (Command Activated) * 2 (Spell Level) * 3 (Caster Level) = 10,800 GP = 1,080 IM -> 810 IM (Lya Price)

Finally, we need energy. Ironically enough, we get the best ratio of ED / GP by the lowly Shocking Grasp. To get half-way regular values, we will assume a basic "Power Unit" of 4d6 ED, which we average out to 14 ED. Each unit costs:
Power Unit / Shocking Grasp: 1800 GP (Command Activated) * 1 (Spell Level) * 4 (Caster Level) = 7,200 GP = 720 IM -> 540 IM (Lya Price)

Which gives us a final table of:
Part GP IM Lya
Rails (per meter) 26,000 GP 5,200 IM 5,200 IM
Make Whole 10,800 GP 1,080 IM 810 IM
Chill Metal 10,800 GP 1,080 IM 810 IM
Power Unit (per 14 ED) 7,200 GP 720 IM 540 IM
3. Final Design
Now we plug everything together. For the final calculation of total kinetic energy of the projectile, we will assume a energy loss of 25% during acceleration. We will use a 2m long rail and 20 PU = 280 ED as the power source, while firing a 20kg projectile.

Thus we get:
(420 ED)² * 204.7229 N / ED² * 2m * 0.75 (Energy Loss) =24.0754 MJ

Punching this into the kinetic energy formula, we get our velocity:
SqrRoot( 24.0754 MJ * 2 / 20kg) = 1551.63 m/s

D&D is slightly crazy with falling object damage. A 20kg = ~44 lb projectile would need to travel 40ft per round to do 1d6 of damage. This is pretty bogus, but let's roll with it. We will assume that the projectile has lost 50% of its speed by the time it hits the target.
50 ft / 6s = 2.032 m/s
1551.63 m/s * 0.5 (Speed Loss) / 2.032 m/s = ~ 382d6 of damage -> average of 1337 HP on a direct hit

Total Cost:
Materials: 10,400 IM
Crafting Materials: 12,420 IM
Time in Days: 62.1
The face of Tywin Lannister when we shell Casterly Rock into rubble: Priceless

4. Ammunition
Due to the forces involved, the projectile has to withstand quite some punishment. Regular steel shells will melt after a while, making them unsuitable for long range fire. So these shells are only really useful for close engagements.

However, there are other options:
Adamantine Tipped(AT) - Directly mitigates the problems by making the tip more sturdy, but it will melt all the same given a few kilometers of flight and once the Adamantine is gone, the steel will evaporate immediately.

Adamantine Mantled(AM) - Unlike the version with just a tip from Adamantine, this one will last a lot longer, but obviously require more Adamantine.

Adamantine Tipped Flat Top Shell (AT-FT) - By making the tip of the shell into a flat surface, we are actually improving the air resistance of the shell. The tip will take quite a bit of punishment, but push the air out of the way and form a vacuum bubble around the shell, which massively cuts down on drag and friction. Also useful for underwater use.

Riverine Tipped Flat Top Shell (RT-FT) - Basically the same as AT-FT, but since Riverine flat out no-sells damage, the melting problem disappears entirely. Obviously a pricey option.

Steel Cannister (SC) - The shell is designed to break apart from drag shortly after launch, releasing shrapnel. Nice to clean up large groups near the gun.

Adamantine Cannister (AC) - Basically the same as above, but by using Adamantine instead of steel, we can extend the distance the shell travels before breaking apart, thus allowing shrapnel bombardments of long range targets.

Before somebody asks, no, we can't fire Wildfyre or other chemically non-inert stuff with this. It would go up in the barrel once the electricity is applied.
However, since the thing is just accelerating metal really, really fast, most of the common defenses against long range strikes become ineffective against it. No SR, no wards, no AM shielding, no nothing.

It's just the wrath of an angry dragon, delivered as a half molten chunk of hyper-sonic death.


@DragonParadox, too far?
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@Goldfish, casual reminder, that we'd want to put that on our Flagship, eventually.
:V
[/jk, but not really - we'll need a lot of research for getting even the idea IC]
 
DragonParadox said:
Since you have never seen the skull just the severed head, I'm going to say no. Naratively things work out a lot better if you can't just take an automatic short-cut. It's the same reason I ruled that Ears of the City and talking to chairs cannot replace talking to people.
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I don't want it as a shortcut, I just want the skull. I was hoping to use it for Yi Ti stuff instead of for this dungeon.
 
Can we get an interlude while waiting for more people to vote?

City of Brass, maybe?
 
Or Yi-Ti, as one needing at least 3-4 more interludes this month, and getting us as much context to local politics as possiBle.

Or clean-up of Drunken God's cult (likely several interludes)
Or dealing with Lyseni Fey Bazaar (same).

Or any of the Research Actions.

We... Have a lot to cover away from Viserys' perspective.
 
egoo said:
Or Yi-Ti, as one needing at least 3-4 more interludes this month, and getting us as much context to local politics as possiBle.

Or clean-up of Drunken God's cult (likely several interludes)
Or dealing with Lyseni Fey Bazaar (same).

Or any of the Research Actions.

We... Have a lot to cover away from Viserys' perspective.
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Yeah, but Harrenhall involves high-level combat.
So that promises more fun to me.
 
OK I'm doing Harenhall, but I can't jump right to the combat,it would not fit Mell's character and it will just make her look like a huge beatstick and nothing else. Much like with Walder Iwant her to come across right.
 
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Interlude DXXI: The Seventh Soul
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    • The Seventh Soul ​

    First Day of the Tenth Month 293 AC

    Kali walked slowly through the crackling leaf-litter at the edge of the lord's wood, following the grunts and squeals of the pig herd. This was his first time doing this alone, and truth be told he was more than a little nervous about the responsibility. These pigs were worth a dozen times over what all his family's worldly possessions were. If there was a wolf about...

    The boy shook himself. There were no wolves this close to the keep, he wasn't a baby anymore to believe nursery tales about old Harren's curse drawing hungry beasts to the keep every year. There hadn't been anyone killed by a beast hereabouts since old Rob, and half the folk were saying even he might have rolled off the back of his donkey dead drunk for the dogs to eat. Of course his mother claimed that had just been ill wishing from the Tanners on account of wanting to claim his donkey afterwards when it had wandered in...

    Alas the calming account of village gossip was broken by the soft sound of twigs scratching, branches moving. Kali whirled around club already at the ready to smash the wolf that must surely have sneaked up on him only to find that it was something far more terrifying that a wolf... a lady. A foreign lady yet, dressed all in red with hair the color of sweeping flame and what looked like a living spark at her throat. A witch... Mother above preserve me at least a wolf would kill me clean, the young pig herder thought.

    "An odd place to give devotion to the Seven to be sure," the witch, or lady, or whatever the hells she was said, and only then did Kali realized he was praying aloud.

    "That is... I... the pigs... I have to..." Something about her voice made him stop and stare, not like he would stare at Maisie Miller mind, more like he had seen a field hand stare at a snake. Beautiful like a bonfire.

    "They have been doing a rather poor job of answering of late, haven't they? Especially here," the strange woman continued. As she motioned towards the woods and the small familiar village down the slope, Kali found himself nodding without knowing why. It did all look sort of dreary all of a sudden, like the light of the sun had grown pale and tired even though it wasn't yet past midday.

    "It is not for us to judge the gods, m'lady," the boy finally managed to get his voice back. He remembered Septon Meryn saying that at Old Will's funeral last month, but it just felt to empty now, and there wasn't even a corpse around to make things strange.

    "Well, if we do not judge the gods, then who will?" the red woman asked idly. "When your father taught you the paths he insisted that you learn them all so that you would not be lost in the woods, did he not?"

    "My uncle, my father's dead, m'lady." Kali gulped, not sure where this was going.

    "Yet he did not then hand you a blindfold and tell you to walk with it, trusting only your memory of walking besides him and not your own eyes." For just a moment she almost looked sad, less like some strange effigy from foreign lands and more like an ordinary woman, but the moment was over so quick the boy could not be sure of it.

    "No, but we can't really see what the gods have in store for us can we..." The boy groped around for the words. "It's like we are born without eyes so we have to trust them."

    "And do the gods you serve allow this?" She shook her head. "I serve a god of light, and through him you may see the path ahead for you to step from shadows into radiance, even as your kin have once stepped from true darkness."

    "I... what...?" Part of him wanted to run away, part of him wanted to run towards whatever she was offering.

    "Of all those alive today, you have most of the blood of Harren the Black of House Hoare, and through you he might finally be laid to rest," she answered pliantly... impossibly. "You can better the lives of all those who dwell within Harrenhal and beyond, kith and kin, and even those who hold you in no great esteem will owe you a debt that can never be paid back."

    "So you really are a witch?" Kali blurted, promptly wishing that he had swallowed the words or perhaps that the ground would swallow him.

    "Such as you understand the term, I am," she replied, seeming to flicker before his sight like a figment upon waking, only to stand between two pale poplar trees further away.

    Caring nothing for pigs the boy walked closer again, he never looked back.

    ***​

    Eleventh Day of the Tenth Month 293 AC

    The morning light spilled through the windows of the Kingspyre Tower red and wrathful as six travelers gathered in the hall to face a great evil... six travelers and one strange boy.

    "What's with him?" Ceria Storm asked as she looked the child up and down. He did not look like any kind of mage and the less said for his ability as a warrior the better. The hungry winter of his youth had not been kind to Kali.

    "He shall be our final key in entering the Fallen King's halls," the Lady Melisandre replied.

    At the word 'key' the boy took out a small bottle and drank it to the last drop. It tasted sweet... he felt light... light enough to float away... he was light and air and fire, R'hllor's fire.

    "You killed him," he heard the knight shout distantly. Only then did Kali turn to see his body pale and glassy-eyed on the floor behind himself.

    "You say that as though the doors of death are sealed to any of us, Ser Knight," the priestess said softly. "When our task here is done I will see him restored to life..."

    "And what if we fail!" the man snapped.

    Kali expected the priestess to answer that R'hllor would not let them falter doing his work, but to his surprise she said. "Then he will have made the same sacrifice as the rest of us, a worthy one I think, or we would not be standing here. Come." The shadows opened a path before them.

    OOC: I tried doing this from Mel's PoV, but without the surprise at the end it just does not work. Anyway here we are with Melisandre. She is a fanatic, certainly, but she has a more complex relationship to her god than 'my god is good because he is mine and all others are demons'.
     
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    • DragonParadox said:
    expected the priestess to answer that R'hllor would not let them falter doing his work, but to his surprise she said. "Then he will have made the same sacrifice as the rest of us, a worthy one I think or we would not be standing here. Come." The shadows opened a path before them
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    I also feel this should be

    "Then the dragon king will shell out a tremendous number of diamonds and turn this province to glass."

    and from a strict numbers perspective, depending on what he is... His chances of actually making it out are higher as an undead.

    Ah but look at me nitpicking, I digress. Still.
     
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    zxzx24 said:
    I also feel this should be

    "Then the dragon king will shell out a tremendous number of diamonds and turn this province to glass."

    and from a strict numbers perspective, depending on what he is... His chances of actually making it out are higher as an undead.

    Ah but look at me nitpicking, I digress. Still.
    Click to expand...
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    That is actually a character point, Mellisndre is not used to depending on others to bail her out.
     
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