Illustrating the Aftereffects of a Doomsday Weapon

[Leliel]

One of my BBEGs, a fairly sympathetic Mad Scientist, has as his ultimate scheme to create and detonate a weapon with the equivalent of a petagram (10 to the 15th power) of TNT in raw blast power, so as to permanently put an end to all wars by confronting the world with it's horrors. Fairly basic plot, except by the time the PCs confront him and he makes his Bond villain speech, he's already started the blast process 30 minutes before then (he read Watchmen, apparently), and the PCs never get a chance to stop him.

Leaving aside the obviously bittersweet ending (they still get to save what's left of the world), how do I illustrate the weapon's effects? Beyond the massive crater, I mean.

[puppyavenger]

One of my BBEGs, a fairly sympathetic Mad Scientist, has as his ultimate scheme to create and detonate a weapon with the equivalent of a petagram (10 to the 15th power) of TNT in raw blast power, so as to permanently put an end to all wars by confronting the world with it's horrors. Fairly basic plot, except by the time the PCs confront him and he makes his Bond villain speech, he's already started the blast process 30 minutes before then (he read Watchmen, apparently), and the PCs never get a chance to stop him.

Leaving aside the obviously bittersweet ending (they still get to save what's left of the world), how do I illustrate the weapon's effects? Beyond the massive crater, I mean.

A shockwave, the rending of ley-lines causes magic to go wild, it opens a gate to the plane of fire/negative energy, destruction spirits/giant ash-clouds blocking out the sun/How big a crater arew we talking exactly?

[Azerian Kelimon]

One of my BBEGs, a fairly sympathetic Mad Scientist, has as his ultimate scheme to create and detonate a weapon with the equivalent of a petagram (10 to the 15th power) of TNT in raw blast power, so as to permanently put an end to all wars by confronting the world with it's horrors. Fairly basic plot, except by the time the PCs confront him and he makes his Bond villain speech, he's already started the blast process 30 minutes before then (he read Watchmen, apparently), and the PCs never get a chance to stop him.

Leaving aside the obviously bittersweet ending (they still get to save what's left of the world), how do I illustrate the weapon's effects? Beyond the massive crater, I mean.

Nothing. Because you didn't tell us the most important thing:

Which game system are we talkin' 'bout?

[Zeta Kai]

Well, there's nothing wrong with starting at the first obvious side effect: nuclear winter.

Then there's the resulting mutants; either the realistic (IE mostly dying) kind or the unrealistic (IE super-powered) kind.

[Newtkeeper]

Which game system are we talkin' 'bout?

All the best descriptions are system neutral. Nuclear Winter is good (lower global temperatures/sunlight-->lowered food production-->starvation, panic and rioting). There will be mass extinction, there will be human suffering and panic.


Really, this is asteroid impact scale damage. Remember the last time we had one of those?

[RS14]

Well, there's nothing wrong with starting at the first obvious side effect: nuclear winter.

Then there's the resulting mutants; either the realistic (IE mostly dying) kind or the unrealistic (IE super-powered) kind.

It wasn't clear to me that this is a nuclear device, and in any case, I don't believe even a detonation of this magnitude would cause significant cooling by itself (though this might depend on the manner in which the blast occurred - centered on the ground would be very different from an air burst).

You probably already have a clear idea of the magnitude - 20 times the size of Tsar Bomba; 1/100,000th the size of the Chicxulub impact, for those who aren't. Let me quote wikipedia on the Tsar Bomba test. I'd just use the same distances at which burns and shockwaves cause signifigant damage.

The original U.S. estimate of the yield was 57 Mt, but since 1991 all Russian sources have stated its yield as 50 Mt. Khrushchev warned in a filmed speech to the Communist parliament of the existence of a 100 Mt bomb (technically the design was capable of this yield). The fireball touched the ground, reached nearly as high as the altitude of the release plane, and was seen and felt 1,000 km away. The heat from the explosion could have caused third degree burns 100 km away from ground zero. The subsequent mushroom cloud was about 60 km high (nearly seven times higher than Mount Everest) and 30–40 km wide. At its peak it is well over 41 miles tall, and 27 miles thick. The explosion could be seen and felt in Finland, even breaking windows there. [5] Atmospheric focusing caused blast damage up to 1,000 km away. The seismic shock created by the detonation was measurable even on its third passage around the Earth.[6] Its Richter magnitude was about 5 to 5.25.

Edit: Did some calculations; it looks like the fireball ought to have a radius of about 20km.
Edit2: Hm, retroactively ninja'd.
Edit3: More calculations: at the optimum height for overpressure, blast damage due to overpressure ought to extend out to a radius of 140km, though the figures I used were on wikipedia with no citation.

[Funkyodor]

Yay, a big bomb. You do realize you are saying an explosion equal to 1,000,000,000 tons of TNT? One of the largest historical bombs detonated was only roughly equal to 50,000,000 tons of TNT. So maybe you're looking at a 20-25 km blast radius of total carnage, or to put it in Greyhawk perspective, about a full Hex on the map...

Several possible aftereffects:
- Surface explosion might cause large fissures in the surrounding region, possibly destabilizing all tectonic plate activity (random earthquakes & volcanos)

- blast area could result in a super volcano like yellowstone national park, watch Stargate Atlantis episode where part of the planet explodes.

- Climate shift into rapid cooling, or rapid heating. Violent weather patterns that are very hard to predict (or change if tech/magic is involved that can do this)

- Departure of all animal life. This could be a good thing to put in as the players are journeying towards the BBEG lair. Animal life going crazy, familiars having queasy feelings, etc.

- Creation of strange metals or materials at ground zero.

- If said world has inherent magic, then have some random wonki-ness affect every bit of it for a while, while the center of the blast could either be magic rich or free. Or if said RPG system supports multiple planes of existance, then have survivors blown into random planes, cities intact and perfectly preserved. As if they'd been there the whole time. If there isn't magic, then maybe there is afterwards.

- Anyone exploring within the kill-zone could encounter strange after images of what used to be, like ghost images.

- Random survivors suffering no side effects.

- Random people who drop dead with no symptoms.

- Alot of people who develop strange ailments that quickly change to life threatening situations which don't respond to any form of medical/magical treatment.

[Azerian Kelimon]

All the best descriptions are system neutral. Nuclear Winter is good (lower global temperatures/sunlight-->lowered food production-->starvation, panic and rioting). There will be mass extinction, there will be human suffering and panic.


Really, this is asteroid impact scale damage. Remember the last time we had one of those?

See, in GURPS, such a disaster screws you totally.

D&D? Dozen ways of preventing it, another hundred of reducing the effect to 0.

[Newtkeeper]

See, in GURPS, such a disaster screws you totally.

D&D? Dozen ways of preventing it, another hundred of reducing the effect to 0.

While I'm all for GURPS, I think you overestimate a DnD hero's ability to cancel out this scale of damage. Stop it? In his sleep. Clean it up? Not so much. Really, once it happens, there's only so much even a level 20 wizard (read: a demigod) can do. The sky is darkened, the crops are failing. People are panicking. There are few rule-sets with terraforming rules (magic or otherwise)- and you're going to have to terraform, if you don't want to just wait it out for a few years.

The only real difference between this in DnD and GURPS is the immediate effect of standing near the explosion. In DnD, anyone with evasion and a half-way decent reflex save will survive it. Without a scratch. In GURPS, you are dead. Like you deserve to be, for standing near that monstrosity of a *~!KABOOM!~*

[Glawackus]

People showing up as ash outlines on buildings they were near was common after Hiroshima, and incredibly, incredibly creepy.

[Azerian Kelimon]

While I'm all for GURPS, I think you overestimate a DnD hero's ability to cancel out this scale of damage. Stop it? In his sleep. Clean it up? Not so much. Really, once it happens, there's only so much even a level 20 wizard (read: a demigod) can do. The sky is darkened, the crops are failing. People are panicking. There are few rule-sets with terraforming rules (magic or otherwise)- and you're going to have to terraform, if you don't want to just wait it out for a few years.

The only real difference between this in DnD and GURPS is the immediate effect of standing near the explosion. In DnD, anyone with evasion and a half-way decent reflex save will survive it. Without a scratch. In GURPS, you are dead. Like you deserve to be, for standing near that monstrosity of a *~!KABOOM!~*

Between at wills of cure disease, Heal, and whatever that spell that terraforms the terrain, if you find good visual guides, then use magic judiciously, you can have everything back to normal in a pair of weeks.

[RS14]

People showing up as ash outlines on buildings they were near was common after Hiroshima, and incredibly, incredibly creepy.

This is a good point. I think you could homebrew some interesting undead which can only be seen as such outlines on buildings.

[Gwyn chan 'r Gwyll]

I would rule that if you were anywhere NEAR that explosion, you die, no save. Too bad.

[Prometheus]

I always thought that fire and ash raining from the sky was a good one, it can be very picturesque and definitely implies global ruin. Whatever it is, I think it should be beautiful, especially if it is an ending.

As for post-apocalyptia, few survivors and harsh environment inevitably yield to either a utopia or a brutal feudalistic system, depending on the slant you want to put on it. Rather than simply rebuilding from the pieces, there should be many features of the transformed planet that they actually adapt or thrive on, illustrating how they can never forget the "birth" of their world.

[Jack_Simth]

Oh, and don't forget that there should be a handful of random survivors near (or even at) ground zero. Historically, people occasionally survive the strangest things.

[Waffles]

Final Fantasy 3/6?

[Newtkeeper]

Between at wills of cure disease, Heal, and whatever that spell that terraforms the terrain, if you find good visual guides, then use magic judiciously, you can have everything back to normal in a pair of weeks.

I doubt weeks. I don't think they have any terraforming spells- control weather is the closest DnD gets, I think. And I don't know of any class (though I haven't played DnD in a while, so they mighth have snuk one in) that gets healing at will. There'll be a pretty high "wound to spell slot" ratio. And that's assuming you haven't blasted the Weave to smithereens.

Control Weather might be useful- high altitude rains to clear the ashes from the sky, to start with, but you're probably looking at months, at least. Assuming everyone cooperates. Which, humans being humans, seems unlikely.

[Pie Guy]

Well, there's nothing wrong with starting at the first obvious side effect: nuclear winter.

Then there's the resulting mutants; either the realistic (IE mostly dying) kind or the unrealistic (IE super-powered) kind.

This would lead lead to the following conversation:

Player 1"I call superpowered mutant!"
Player 2"You can't do that I want the superpowered mutant!"
1"Nya-nya!"
2"Why do I always get stuck with the cancerous mutants..."

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Also I heard from somewhere that mindflayers came back in time from the end of the world, so something with that?

[Triaxx]

Mercedes Lackey actually did a very good version of this. Two superweapons were activated. One carved out an enormous bowl shaped plain. The other created an enormous lake.

Remember that the shockwave is going to be exceedingly powerful. Flatten a city some miles away. Move a lake around.

Copy your world map, and then change it around. The deeper you bury the 'bomb' the more tectonic the changes. This thing could sink the better part of a continent. Set it off underwater, and have an instant Tsunami.

[Bigbrother87]

Mercedes Lackey actually did a very good version of this. Two superweapons were activated. One carved out an enormous bowl shaped plain. The other created an enormous lake.

Remember that the shockwave is going to be exceedingly powerful. Flatten a city some miles away. Move a lake around.

Copy your world map, and then change it around. The deeper you bury the 'bomb' the more tectonic the changes. This thing could sink the better part of a continent. Set it off underwater, and have an instant Tsunami.

Specifically, in the Mage Storms/Griffon trilogies.

Two wizards with many, many magical devices, are at war. One (the "good" one), invents two devices to release ALL of the magic inside all of the devices nearby, at once. Sends his people away to safety, and sets a device off in both wizard's towers....Magic goes sploosh all over. If I recall correctly, there was a week of strong magic waves sweeping across the land, and where the shockwaves from both explosions met, strange things happened. The magic of the world was basically blown into the sky, to trickle back down as time went by into reformed ley lines and pools of power. Both towers became craters, but one had rivers flowing into it, to become the largest lake in the area. All of the land in between the craters became corrupted, warped, and dangerous to all parties because of the effects the magic had on the wildlife and plants.

But, it's not over. hundreds/thousands of years later, we find out that the magic waves were so powerful, that they circled the globe back then, and are now echoing Backwards, creating more chaos by transporting and warping things were the waves meet again.

The final reverse explosion was only stopped by setting of another explosion to cancel it out...much fun. What that has to do with your needs...not much, but this illustrates another, magic induced, world changing disaster.

[Griffin131]

Find out what the calculations for http://meyerweb.com/eric/tools/gmap/hydesim.html come from. Rewrite it to allow larger than 10,000 KT. That'll get you the instant destruction area, fairly accurately anyway.

[endoperez]

Don't let the players react to stuff that happens except in the very beginning. Stuff already happened, and after the first week or few, whenever they come to a new area they're already late. They decide to go help the city-of-that-guy-that-gave-a-quest-long-time-ago now that things are better off in the capital? It is in ruins, but local heroes arose and are keeping peace. They drove off the monsters but suffered horrible losses. Or perhaps everyone is dead already, the city just ash and an empty, roofless stone skeleton which was once the inn they liked.

Magic goes haywire. In some places, whole forests spring into being in the matter of weeks, transform into jungles and cover all signs of civilization. Elsewhere, nothing grows, nothing is born, everything and everyone is permanently infertile. Waves of unseasonal heat and cold go around affecting spesific areas, with permanent storms with hail and thunder where the areas overlap. In most places, the effects start fading away quickly but can still last for months or years.

Track time. For the first week, magic is a bit weaker (-1 to casting stats for everyone), but otherwise fine. Then all magic becomes less and less powerful, first for potions and scrolls fail, then casters lose two or three of their highest spell levels, then permanent items fail... just when they start to panic, everything returns to normal in the matter of hours, with some fluctuation afterwards so that some days, magic is more powerful than normal, some days less.

Money is worthless, a single Create Food and Water can buy the players almost anything. They're offered most of that, as well, from money to wives to slaves to magic items. Some spell ingredients are impossible to find. Diseases abound, some monsters rampage, others are too afraid to do anything but hide.

Rumours are everywhere. Every town has a different explanation for the event, and a different name. The Armageddon, End of the World, the Breaking, the Cataclysm, The Day Gods Died, whatever. They aren't necessarily willing to listen to alternate explanations.

What do gods do? What can they do? Will they kill the Bad Mage on the spot? If so, look at Greek legends for fates that could befall him.

[Funkyodor]

You can also look up Krakatoa. It was estimated to be around 200 megatons with an explosion that could be heard from 2-3 thousand miles away. Supposedly Edvard Munchs "The Scream" was derived from atmospheric conditions changed as a result of the eruption. It could give you a good estimate of weather pattern changes, death toll, etcetera.

[MorkaisChosen]

If this is a fantasy setting, the epicentre should become a portal to some kind of evil-death-plane. There's a fantasy trope of places where lots of people died becoming tainted, and this is a perfect place to put HUGE amounts of taint.

Also, some kind of "incorporeal" undead made of ash- possibly the combined remains of several victims, swirling up ino a semi-humanoid amalgamation of their forms and speaking in all their voces.

[Worira]

You can also look up Krakatoa. It was estimated to be around 200 megatons with an explosion that could be heard from 2-3 thousand miles away. Supposedly Edvard Munchs "The Scream" was derived from atmospheric conditions changed as a result of the eruption. It could give you a good estimate of weather pattern changes, death toll, etcetera.

Tambora could kick Krakatoa's butt.