OOTS #1186 - The Discussion Thread

[Quizatzhaderac]

The real question is, what kind of damage does a nuclear explosion deal? I feel like it would deal a large amount of radiant damage on detonation, and everyone in the blast radius would have to save vs. blindness. Then probably fire damage post-explosion, and then...I don’t know...maybe poison damage, to represent the falllout? Or some kind of disease? I know very little about 3.5 edition.

The short version is: if it goes off where PCs can see it just cut away to the afterlife, true resurrections required for everyone. Like "rocks fall, everyone dies" except the rocks are dead too.

I'd model as (treating is as a 20 MT blast):

Fire damage: 1 D6 per 34 km/ radius (treating third degree burns as d6). Cover negates, but extraordinary cover is needed. Most of what's normally considered full cover reduced damage by half. If negative hit-points exceed 50 + (4* max) the body is disintegrated.

A fortitude save versus acute radiation poison DC 10*5.4 km/radius. Failure gives 72 hours to live, cure disease is required to fix.

A fortitude save versus multiple organ death DC 3*5.4 km/radius. Failure gives 24 hours to live, regeneration is required to fix. I would let players use raise dead (diamond free) or heal, since the parts are still attached.

Sonic damage: 1D6 per 22.2 km/ radius². If negative hit-points exceed 50 + (4* max) the body is disintegrated. Fort save DC 10 + damage for deafness.

[Rogar Demonblud]

Sounds too involved. "You're all dead, campaign over" is much pithier.

[Jasdoif]

Sounds too involved. "You're all dead, campaign over" is much pithier.

And if your next campaign is set in the Mournland, you might even be able to play out the aftermath vicariously!

[Cazero]

Sounds too involved. "You're all dead, campaign over" is much pithier.

Except the Rogue. He got Evasion.

[MossyMeow]

I didn’t expect my off-the-cuff, somewhat facetious inquiry to spawn so much analysis, but then again, maybe I shouldn’t have been surprised. It’s all par for the course.

Gosh, I love this forum sometimes. You guys are amazing.

[Doug Lampert]

Neither is lava, or falling from orbit.
So, something like 30d8? Maybe less?

I have found only two cases of someone falling on lava. In both cases they got up and walked away with only minor injuries. (Hint: Lava is viscous and denser than you are and a lousy conductor of heat. You hit it and float on the surface, you don't fall into it, that's a movie special effect using water and then coloring it red that you're thinking of, with real lava, if the air is cool enough to survive breathing the air, then the lava has a nearly solid crust that you rest on. Heavy clothes will protect you except where exposed skin touches the lava where you will have serious burns.)

There have been at least 5 cases of someone being ejected from an aircraft at multiple thousands of feet and living. Specifically there was a stewardess who landed in the Amazon basin and had to get up and walk to find rescue, fortunately she had no serious injuries. Same for one of the WWII gunners. Falling from orbit would kill you via suffocation prior to reentry and via reentry heating, but hitting the ground at terminal velocity is quite survivable with sufficient luck in terms of what you hit. (Hint: D&D HP have pretty well always included luck as part of the official explanation of what they are, with luck you can survive a terminal velocity fall, hence HP protect from terminal velocity falls.)

So, yeah, both of those should have damage, and arguably, the damage given in the rulebook is far far too high given that low level NPCs appear quite able to survive those effects.

Nuke at point blank range, that's much less survivable.

[MossyMeow]

I have found only two cases of someone falling on lava. In both cases they got up and walked away with only minor injuries. (Hint: Lava is viscous and denser than you are and a lousy conductor of heat. You hit it and float on the surface, you don't fall into it, that's a movie special effect using water and then coloring it red that you're thinking of, with real lava, if the air is cool enough to survive breathing the air, then the lava has a nearly solid crust that you rest on. Heavy clothes will protect you except where exposed skin touches the lava where you will have serious burns.)

There have been at least 5 cases of someone being ejected from an aircraft at multiple thousands of feet and living. Specifically there was a stewardess who landed in the Amazon basin and had to get up and walk to find rescue, fortunately she had no serious injuries. Same for one of the WWII gunners. Falling from orbit would kill you via suffocation prior to reentry and via reentry heating, but hitting the ground at terminal velocity is quite survivable with sufficient luck in terms of what you hit. (Hint: D&D HP have pretty well always included luck as part of the official explanation of what they are, with luck you can survive a terminal velocity fall, hence HP protect from terminal velocity falls.)

So, yeah, both of those should have damage, and arguably, the damage given in the rulebook is far far too high given that low level NPCs appear quite able to survive those effects.

Nuke at point blank range, that's much less survivable.

Aren’t you actually more likely to survive a nuclear explosion if the bomb is dropped directly overhead? I know that’s what happened in Hiroshima; the building directly under the blast survived, although I don’t know if the people did. Then again, modern bombs might have a different...radius? Is that the right word? I don’t know, I’m far from an expert. I just have a morbid fascination with nuclear weapons.

[Doug Lampert]

Aren’t you actually more likely to survive a nuclear explosion if the bomb is dropped directly overhead? I know that’s what happened in Hiroshima; the building directly under the blast survived, although I don’t know if the people did. Then again, modern bombs might have a different...radius? Is that the right word? I don’t know, I’m far from an expert. I just have a morbid fascination with nuclear weapons.

Both of those were airbursts, IIRC structures directly below were less damaged than those a short distance to the side, because there were no lateral winds to finish off anything not directly destroyed by the radiation and blast if directly under the blast.

I don't believe any people directly below survived, but IIRC it was theorized that someone in a subway or bank vault directly beneath an airburst might survive. This is why effects of nuclear weapons blast radii tend to have a 99%+ fatality zone for the most destructive effects, someone COULD live even at point blank range given appropriate cover.

Point blank from a H-bomb would be less survivable, but they still list the "total devastation" zone as 99%+ fatality rather than 100%, because stuff happens and people can be very hard to kill (or they can die slipping in the bathroom, stuff happens both ways).

OTOH, 99%+ fatalities does not in any way contradict the claim that this is much less survivable than 10,000' free falls or falling onto lava. Falling onto lava is notably non-fatal in the available data. Point blank from a bomb is just "we think it might not kill you if stuff happens just right".

[MossyMeow]

Both of those were airbursts, IIRC structures directly below were less damaged than those a short distance to the side, because there were no lateral winds to finish off anything not directly destroyed by the radiation and blast if directly under the blast.

I don't believe any people directly below survived, but IIRC it was theorized that someone in a subway or bank vault directly beneath an airburst might survive. This is why effects of nuclear weapons blast radii tend to have a 99%+ fatality zone for the most destructive effects, someone COULD live even at point blank range given appropriate cover.

Point blank from a H-bomb would be less survivable, but they still list the "total devastation" zone as 99%+ fatality rather than 100%, because stuff happens and people can be very hard to kill (or they can die slipping in the bathroom, stuff happens both ways).

OTOH, 99%+ fatalities does not in any way contradict the claim that this is much less survivable than 10,000' free falls or falling onto lava. Falling onto lava is notably non-fatal in the available data. Point blank from a bomb is just "we think it might not kill you if stuff happens just right".

Something tells me testing any of those hypotheses would be a breach of scientific ethics, which is probably why it’s still a mystery. That being said, I think even the most curious scientists would rather not have nuclear weapons devastate entire cities, regardless of the possible data that could provide. Then again, as the radius of an explosion increases...

[Dion]

Something tells me testing any of those hypotheses would be a breach of scientific ethics

Right, but suppose Xykon does somehow catch O’Chul again, allowing these tests to be performed in an unethical manner.

If you put a paladin in the fridge, does he survive a bomb?

[Schroeswald]

Right, but suppose Xykon does somehow catch O’Chul again, allowing these tests to be performed in an unethical manner.

If you put a paladin in the fridge, does he survive a bomb?

Who said anything about a fridge? I’m sure O-Chul could survive a nuclear bomb fridgeless, he’d make the fort save for half damage, the bomb would roll low in damage and he’d survive (with negative hit points).

[bunsen_h]

Sounds too involved. "You're all dead, campaign over" is much pithier.

If the DM is inclined to be merciful / generous, there's some precedent in the rules for "a rip got torn in the fabric of the multiverse, let's see where you fell through to". Depending, perhaps, on whether the PCs were directly responsible for the disaster.

Let some good come of the plot of Farnham's Freehold.

[Gnoman]

Aren’t you actually more likely to survive a nuclear explosion if the bomb is dropped directly overhead? I know that’s what happened in Hiroshima; the building directly under the blast survived, although I don’t know if the people did. Then again, modern bombs might have a different...radius? Is that the right word? I don’t know, I’m far from an expert. I just have a morbid fascination with nuclear weapons.

A nuclear blast does damage in more than one way. The initial energy release is emitted as a thermal pulse - as this is absorbed into the atmosphere it generates an enormous fireball. In the case of Hiroshima, the burst altitude was high enough that the fireball did not reach the ground. The thermal pulse doesn't end there - it continues well outside the fireball setting fire to almost anything* that can burn, etc. The next feature is that of wind - all that energy being dumped into the atmosphere generates a wind that dwarfs any tornado or hurricane. This last bit doesn't go downward very much, as there's a massive updraft going into the vacuum created by the blast. It is theoretically possible that a sturdy structure could keep out the thermal pulse and the wind blast, but very unlikely that you wouldn't be asphyxiated as air got sucked upward.



* Reference this terrifying quote from a pilot who was supposed to fly through after a test blast to gather atmospheric data, except on one mission where timing got screwed up.

In reviewing the flight, we found that the heat reflected off the overcast and onto my F-84 had burned away or wrinkled the skin on the flaps, stabilator, and ailerons. The glare shield above the instrument panel, and all of the black tape windings on the instrument lines behind it, were completely burned away. The hydraulic fluid that had leaked out around the rudder pedals had created other fires. The lens on the over-the-shoulder camera inside my protective hood had melted. Of the three layers of asbestos and aluminum cloth that made up the hood itself, two were incinerated.

[danielxcutter]

...Isn't asbestos literally supposed to be non-flammable?

[Peelee]

...Isn't asbestos literally supposed to be non-flammable?

Technically everything is flammable if you just get it hot enough. [/badscience]

[Quizatzhaderac]

Aren’t you actually more likely to survive a nuclear explosion if the bomb is dropped directly overhead?

Buildings are definitely more likely to survive. A person in a surviving building is much more likely to survive.

We also have data from the Tunguska meteoroid about what a 30 MT blast would look like; trees at the center were scorched but not knocked down.

Point blank from a H-bomb would be less survivable, but they still list the "total devastation" zone as 99%+ fatality rather than 100%, because stuff happens and people can be very hard to kill (or they can die slipping in the bathroom, stuff happens both ways).

There's a distinction to be made between "ground zero" and "point blank".

The numbers I see all assume airburst as the "normal" and most effective. Which means person closest on the ground might still be kilometers away.

If the target is a supervillain or kaiju (instead of a city) it would make more sense to detonate the the bomb right on top of the target. Or circling back OotS, if Redcloak summoned a plutonium elemental and cast implosion on it, the OotS would likely be within a few hundred feet, if not the same room.

If we look at underground test figures, probably the best indicator is the "Melt cavity" which is the radius in which solid rock is melted/vaporized. For an 8MT bomb that would be about 160 meters (105 squares). Dungeon figures would be much higher since the dungeon isn't solid rock and the simulation figures assume hundreds of atmospheres of ambient pressure from the enclosing earth. Also, assuming the radiation/heat/shock-wave doesn't kill them, there's still the matter of the vapor bubble collapsing at the end (i.e. ceiling collapse)

[Doug Lampert]

...Isn't asbestos literally supposed to be non-flammable?

Define flammable. Anything will vaporize with enough energy applied.

Typically, flammable means you can get a (rapid) self-sustaining exothermic reaction going in the Earth's atmosphere via oxidization.

Asbestos was used as a fire-retardant, because it's a very good insulator, and stable up to quite high temperatures, but that's not the same as fire-proof. Asbestos will react exothermically if you apply enough heat and pressure, "normal" fires just don't get that hot and I don't know if you could get this to be self sustaining particularly easily.

[bunsen_h]

Define flammable. Anything will vaporize with enough energy applied.

The word used in the quoted report was "incinerated". That's not well-defined. There are a number of kinds of asbestos with varying properties, but what I'm seeing on web pages about what happens to it at high temperature is about melting points, not decompositions.

Asbestos was used as a fire-retardant, because it's a very good insulator, and stable up to quite high temperatures, but that's not the same as fire-proof. Asbestos will react exothermically if you apply enough heat and pressure, "normal" fires just don't get that hot and I don't know if you could get this to be self sustaining particularly easily.

It's not true that "anything will burn if you get it hot enough", as the saying goes. Some things are as "burned" as they're going to get; that is, have already reacted with as much oxygen as they possibly can. At high temperature, some things decompose; others melt, then vaporize as compounds with the same composition as the original solid form.

Asbestos is differentiated from other silicate minerals by its crystal form: long thin fibers. Once it has melted, it isn't asbestos any more; it's molten generic silicate material. All of the asbestos types have some hydroxyl groups (OH) in their composition, so if you get that molten material hot enough, you're probably going to lose some water from it as vapour -- that is, a decomposition reaction. I don't know what would happen after that. If you let it cool down again, you're unlikely to get it to crystallize back into the asbestos form (even if you don't lose the water) unless you hit the right ranges of temperature and pressure... and stay there a good long time. Cool it too quickly and you get glass.

[factotum]

It's not true that "anything will burn if you get it hot enough", as the saying goes. Some things are as "burned" as they're going to get; that is, have already reacted with as much oxygen as they possibly can.

Which doesn't mean they won't "burn", they just won't burn with oxygen. Use something like chlorine trifluoride and you can quite happily set fire to bricks and sand.

[danielxcutter]

Which doesn't mean they won't "burn", they just won't burn with oxygen. Use something like chlorine trifluoride and you can quite happily set fire to bricks and sand.

According to xkcd's What If, dioxygen difluoride (O2F2) can literally make ICE catch on fire.

[factotum]

According to xkcd's What If, dioxygen difluoride (O2F2) can literally make ICE catch on fire.

ClF3 will do that as well, although it'll react explosively with the water from the melting ice. They dropped a ton of the stuff once and it burned its way through a foot of concrete and eighteen inches of sand and gravel underneath before they got it under control.

[Jasdoif]

ClF3 will do that as well, although it'll react explosively with the water from the melting ice. They dropped a ton of the stuff once and it burned its way through a foot of concrete and eighteen inches of sand and gravel underneath before they got it under control.

Ah, now I know why it sounded familiar.

[Peelee]

According to xkcd's What If, dioxygen difluoride (O2F2) can literally make ICE catch on fire.

Ahh, good ol' FOOF. FOOF is fun. If asked, "how reactive is FOOF," the answer is "yes."

[factotum]

Ah, now I know why it sounded familiar.

Never seen those. I do like John D. Clark's description of the stuff in his book about rocket fuels, "Ignition":

It is, of course, extremely toxic, but that's the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water—with which it reacts explosively. It can be kept in some of the ordinary structural metals—steel, copper, aluminum, etc.—because of the formation of a thin film of insoluble metal fluoride that protects the bulk of the metal, just as the invisible coat of oxide on aluminum keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.

[Peelee]

Never seen those. I do like John D. Clark's description of the stuff in his book about rocket fuels, "Ignition":

That book is sitting in a small "to be read" pile right next to me at the moment!

[halfeye]

According to xkcd's What If, dioxygen difluoride (O2F2) can literally make ICE catch on fire.

ClF3 will do that as well, although it'll react explosively with the water from the melting ice. They dropped a ton of the stuff once and it burned its way through a foot of concrete and eighteen inches of sand and gravel underneath before they got it under control.

What (theoretically), would be the result of mixing those two? I don't want to be within miles of anyone who tries, but there is theory about these things I presume.

[Peelee]

What (theoretically), would be the result of mixing those two? I don't want to be within miles of anyone who tries, but there is theory about these things I presume.

Not to sound like a broken record, but...

If asked, "how reactive is FOOF," the answer is "yes."

I think you need to get FOOF to double digit K to get it to be non-explodey. Also, you could call it dioxygen diflouride or O2F2, but when you can call it FOOF instead, why would you?

[Tvtyrant]

Never seen those. I do like John D. Clark's description of the stuff in his book about rocket fuels, "Ignition":

It is, of course, extremely toxic, but that's the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water—with which it reacts explosively. It can be kept in some of the ordinary structural metals—steel, copper, aluminum, etc.—because of the formation of a thin film of insoluble metal fluoride that protects the bulk of the metal, just as the invisible coat of oxide on aluminum keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.

Is that the one that creates chlorine gas as a byproduct?

The one that bothers me is the Lye Soap and Aluminium or draino and aluminum ones, because those are absolutely things that can happen.

[bunsen_h]

What (theoretically), would be the result of mixing those two? I don't want to be within miles of anyone who tries, but there is theory about these things I presume.

Both FOOF and ClF₃ are extremely reactive because fluorine is a very powerful oxidizing agent, and it's present in those compounds in a form that has a very low barrier to reaction. They cause fluorination reactions. And both of them are quite unstable themselves, and decompose easily.

I don't think they'd react with each other; they're not going to fluorinate each other. But...

Hydrogen peroxide and sodium hypochlorite (i.e., bleach) are both pretty strong oxidizers, semi-stable. Mix them together and you get a fairly violent reaction that releases oxygen gas -- the two cleaning agents essentially neutralize each other. Fun chemistry fact: that oxygen is in an excited energy state and emits an orange glow, just for a moment. It's not very bright, and you have to use fairly concentrated solutions in a very dark room, with your eyes well adapted to darkness, to see it.

What I'm trying to get at is that it's possible that by mixing FOOF and ClF₃, you'd trigger them to decompose even under conditions where they'd ordinarily be sort-of-stable, individually. That's a kind of thing I'd rather test at a distance, using automated equipment and (ideally) a disposable lab assistant.

[factotum]

Is that the one that creates chlorine gas as a byproduct?

Hah, you poor summer child. If it only created chlorine gas as a byproduct you'd be laughing. No, it's searing hot clouds of hydrofluoric acid that are the "fun" result of combining ClF3 with water...