GAME RELATED: Anyone know the science behind an orbital nuclear burst?

[Fryguy]

(NOTE: JIC!) Here's the GAME situ. A 5 Kiloton nuclear device was set off over NYC. It was about 70-75 miles from the surface. If anyone has dealt with the science and how it relates in Champions terms to the following I would appreciate it:

 

1) A PC holding the device had the following defenses: He was in a vehicle with a DEF of 25 (2x Hardened) and the vehicle had 20 BOD. In addition the PC himself had a rPD/rED of 20 (2x Hardened). He has 15 Body. He also (personally not the vehicle has LS: Intense Heat, High Radiation, High Pressure, & Vacuum. He has Power Def (10) bit it is neither Hardened nor Resistant. His Flash Def is 10. I made the damage of the nuke a 15d6 KA.

 

2) I know at that distance the radiation will dissipate (I checked online to various info) and the atmosphere will bounce most of the gamma, infra red, and other rays to the point where there will be minimal exposure on the surface. If I am incorrect please let me know.

 

3) The EMP (Electro Magnetic Pulse) is most concerning to me. According to what I've read a 10 KTon burst at that altitude will cause an EMP about 740 miles in diameter. I found the info at the following link: http://en.wikipedia.org/wiki/Electromagnetic_pulse#Characteristics_of_nuclear_EMP

Yield is not the issue- how far it is from the surface IS an issue. But once again if I am wrong about the science please let me know. Thank you for any help!

[Captain Obvious]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

Was the warhead inside or outside the vehicle? Is the character's ED resistant?

 

The quick and dirty estimate for a nuke is 20d6K, although a 5Kton bomb would be a little bit smaller.

[Matt Holck]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

Mechanon is not happy with this EMP Burst

won't somebody think of the circuits!

[Fryguy]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

Was the warhead inside or outside the vehicle? Is the character's ED resistant?

The "vehicle" was a powered suit of armor (ie. Iron Man). He was holding the bomb when it went off. He was doing Megascale movement to get out of the city, hence why it was 70+ miles from the surface.

 

The quick and dirty estimate for a nuke is 20d6K, although a 5Kton bomb would be a little bit smaller.

I did. I make it a 15d6K

[prestidigitator]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

EMP? Pffft! ( ) That would be a pain, but I'd be just as concerned about the fallout. Some kind of cleanup/containment effort could offer some major roleplaying opportunities.

[Sean Waters]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

The "vehicle" was a powered suit of armor (ie. Iron Man). He was holding the bomb when it went off. He was doing Megascale movement to get out of the city, hence why it was 70+ miles from the surface.

 

I did. I make it a 15d6K

 

Well the technical answer is that he is dead.

 

However, in my game he would just disappear, they wouldn't find the body (they MIGHT find the suit). The PC would then find himself playing an energy being with amnesia who has just arrived on Earth.

 

Radiation accident - yeah!

 

I like science but, in a game, I wouldn't worry too much about it. I'd have loads of lightbulbs and computers go on the fritz for colour, but no major EMP damage except one train that has its controls locked by the EMP and has to be rescued by the rest of the PCs.

 

Or planes - that'd probably be in difficulty - and great for rescuing

[Captain Obvious]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

By eyeballing it and not having rolled the actual damage, it seems to me the character would survive the blast with serious injuries, and then, unless he has Flight on his own, will fall to the ground and be knocked into negative BODY by the fall. Unless there's an EMT sitting real close by the impact area, going purely on mechanics, the character's going to die. Sean Waters has some good suggestions though...radiation accidents are always fun. Maybe let the player use another character for a few game sessions before bringing this guy back with a new power set gained from the blast.

[prestidigitator]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

The fall? Hmm. I'd go lenient on a character taking falling damage just after surviving a nuclear blast, myself. Give him part of the suit's PD just for the fall or something. Take the player's pulse to, so to speak. Does he want to continue with the character? Would he be interested in a dramatic change due to a radiation accident? Would he want to roleplay through a tough recovery from such an accident with some possibly interesting complications? Or is he ready to move on completely, and having the character go out in such a "flashy" and impressive act of self-sacrifice is a nice way to move on to a different character?

[Killer Shrike]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

Technically, EMP has no game definition to the best of my knowledge, so unless the player took limitations like "not in strong magnetic fields" on their abilities it's basically a non-issue. There was a thread about EMP's just the other day that you might want to check out: EMP thread

 

That aside, the more likely danger for the character is if the DEF of the vehicle power suit is exceeded, the vehicle will have to roll on the vehicle damage table and might lose a power, which might put the character at some kind of situational disadvantage. If enough damage is inflicted to remove all of the vehicles body, then the entire suit falls apart and the character is going to be severely disadvantaged if he doesn't have a parachute or something. It all depends on how much damage we are talking about here.

[prestidigitator]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

Well, the 15d6K damage looks like enough to completely destroy the Vehicle to me. That's average damage of 52.5 (call it 55). PD 25 and Body 20 looks like toast.

 

You know, I've been looking, and absolutely nowhere in 6E does it talk about passengers taking damage. I'm going to have to break out my 5ER and see if it was missing there too, but I thought I remembered a discussion about it somewhere. I'd generally assume that if passengers are covered by the vehicle's defenses (unlike on a motorcycle or something where the vehicle's PD/ED takes a Limitation), they don't start taking damage until the vehicle is completely destroyed (0 Body). Just like using a Barrier or object for cover, I'd assume that the Vehicle's ED and leftover Body would subtract from the Body damage, and the leftover is about 55-45=10 Body. Is his own ED Resistant? At terminal velocity, the character is going to take 30d6. An average of 30 Body means he's going to take 10 Body in damage after his own 20 PD. That's not enough to take him to negative Body unless he took damage from the explosion, so it all boils down to whether his personal 20 ED is Resistant or not.

 

Again that is if you are going to go with the full damage. If you go easy on a character who just heroically took (and survived) a nuclear blast and give him even 6 rPD PD of the Vehicle's defense against the fall as it disintegrates around him, or even just find him a soft spot to land, he easily could wind up simply tenderized, broken, and in a coma (from the Stun damage) instead of dead.

[Killer Shrike]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

The "vehicle" was a powered suit of armor (ie. Iron Man). He was holding the bomb when it went off. He was doing Megascale movement to get out of the city, hence why it was 70+ miles from the surface.

 

I did. I make it a 15d6K

 

You might want to edit the opening post to include all relevant information so that posters who don't read thru the entire thread are giving you a fully informed response.

[Kraven Kor]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

I'd do thusly:

 

First, I'd roll damage, and I'd do it in the open. Any BODY or STUN not absorbed by the armor goes to the person inside of it. So, in theory, the Armor will absorb 25 BODY of the attack, the player takes anything over that. The armor is DESTROYED if 45 BODY or more is destroyed. The player's own PD is pointless, it isn't resistant - the nuke is a killing attack. The player (if indeed anything is left of him) falls. Then...

 

Ask the player if they are OK with the Heroic Sacrifice Options listed above, or if he wants to survive and keep the character - we all know comic heroes or villains who have survived similar or worse. It is entirely possible that he got the nuke to X altitude then sped off, thus not taking the "full force" of the nuke, fell to the ground in what remained of the suit, and will need hospitalization and the like - seriously injured, possible changes to reflect that (like, now paralyzed when not in the suit, or horribly deformed, or the radiation accident, etc.)

[Killer Shrike]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

Well, the 15d6K damage looks like enough to completely destroy the Vehicle to me. That's average damage of 52.5 (call it 55). PD 25 and Body 20 looks like toast.

 

You know, I've been looking, and absolutely nowhere in 6E does it talk about passengers taking damage. I'm going to have to break out my 5ER and see if it was missing there too, but I thought I remembered a discussion about it somewhere. I'd generally assume that if passengers are covered by the vehicle's defenses (unlike on a motorcycle or something where the vehicle's PD/ED takes a Limitation), they don't start taking damage until the vehicle is completely destroyed (0 Body). Just like using a Barrier or object for cover, I'd assume that the Vehicle's ED and leftover Body would subtract from the Body damage, and the leftover is about 55-45=10 Body. Is his own ED Resistant? At terminal velocity, the character is going to take 30d6. An average of 30 Body means he's going to take 10 Body in damage after his own 20 PD. That's not enough to take him to negative Body unless he took damage from the explosion, so it all boils down to whether his personal 20 ED is Resistant or not.

 

Again that is if you are going to go with the full damage. If you go easy on a character who just heroically took (and survived) a nuclear blast and give him even 6 rPD PD of the Vehicle's defense against the fall as it disintegrates around him, or even just find him a soft spot to land, he easily could wind up simply tenderized, broken, and in a coma (from the Stun damage) instead of dead.

 

Yes, 15d6 K will likely destroy the vehicle.

 

In 5e using the Ultimate Vehicle, if any body exceeded the DEF of the vehicle, you subtracted the DEF from the Body and Stun and applied that remaining damage to all occupants in the vicinity of the attack (based upon hit loc or common sense). The BODY of the vehicle didn't enter into it.

[Kraven Kor]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

I seem to recall that vehicles def, by default, protects the passengers if any attack targets said passengers. There is even a limitation you can take on vehicle DEF if this is not the case.

 

When I do Power Armor in less-than-superheroic campaigns, any BODY damage that exceeds the DEF of the vehicle is applied to both the armor and the wearer. In Superheroic campaigns, I pretty much say you have to reduce the suit to 0 BODY to hurt the passenger.

 

And yes, I now realize that I contradict my previous post - I even changed it before posting, originally stating the suit would absorb 45 BODY and the player would take any BODY beyond that.

[prestidigitator]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

The player's own PD is pointless' date=' it isn't resistant - the nuke is a killing attack.[/quote']

Well, the OP didn't really distinguish between PD/ED and rPD/rED. He did say the character's own PD/ED is double Hardened. I'm not sure we can assume it's not also Resistant.

[Kraven Kor]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

Well' date=' the OP didn't really distinguish between PD/ED and rPD/rED. He [i']did[/i] say the character's own PD/ED is double Hardened. I'm not sure we can assume it's not also Resistant.

 

Blast! Foiled again!

 

A valid point; I didn't even notice the 'hardened' bit on the player's PD/ED.

[Ice9]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

Buying Double Hardened non-Resistant ED seems a bit unlikely, so I'm going to assume it is. In which case, he takes (on average): 52.5 - 25 (vehicle) - 20 (personal) = 7.5 damage. At that point, he's just injured, not even dying. However, he's also taken ~60 STUN (6E, 86 in 5E). So he might be unconcious.

If he falls, that's still not enough to outright kill him, but he'll be in critical condition. Although if you're using the VF rules, I think terminal velocity caps out a bit lower (24d6, IIRC), in which case he'd be all right - seriously injured, but not in danger of dying.

 

Also, the last time I saw the nuke writeup, I believe it had a pressure wave that did a fairly large amount of Blast in addition to the RKA. What effect that has depends on how the attacks are applied. If the Blast applies first or simultaneously, I think the suit may be strong enough to resist it, so the player wouldn't take any damage. If the RKA is considered to occur first, destroying the suit, then the Blast would at least be dealing additional STUN, and maybe BODY.

[AirborneRob]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

The fall? Hmm. I'd go lenient on a character taking falling damage just after surviving a nuclear blast' date=' myself. Give him part of the suit's PD just for the fall or something. Take the player's pulse to, so to speak. Does he want to continue with the character? Would he be interested in a dramatic change due to a radiation accident? Would he want to roleplay through a tough recovery from such an accident with some possibly interesting complications? Or is he ready to move on completely, and having the character go out in such a "flashy" and impressive act of self-sacrifice is a nice way to move on to a different character?[/quote']

 

Kingdom Come comes to mind Out of curiosity, what kind of RKA does HERO give to the city-busters? If a 5 kiloton nuke in the OP's comments rated 15d6 RKA, makes me wonder what a 100 Megaton warhead brings to the table.

[AmadanNaBriona]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

Kingdom Come comes to mind Out of curiosity' date=' what kind of RKA does HERO give to the city-busters? If a 5 kiloton nuke in the OP's comments rated 15d6 RKA, makes me wonder what a 100 Megaton warhead brings to the table.[/quote']

 

Actually, the 20D6K number cited for the "Standard" HERO nuke comes from the Cruise Missie write up, and as the main cruise missile warhead is the 5KT nominal yield W-80, I'd say a 15D6 one would prolly be around a 1KT yield. No idea on the 100 Meg tho, not without doing a bit of a look up for data

[prestidigitator]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

Kingdom Come comes to mind Out of curiosity' date=' what kind of RKA does HERO give to the city-busters? If a 5 kiloton nuke in the OP's comments rated 15d6 RKA, makes me wonder what a 100 Megaton warhead brings to the table.[/quote']

Usually the idea is supposed to be that each doubling of energy adds +1 DC. 5kt to 100Mt is roughly 2^2 kt to 2^17 kt, or 15 doublings. +15 DCs is +5d6K. If we started out with 15d6K, we'd want to scale it up to somewhere around 20d6K.

 

Actually' date=' the 20D6K number cited for the "Standard" HERO nuke comes from the Cruise Missie write up, and as the main cruise missile warhead is the 5KT nominal yield W-80, I'd say a 15D6 one would prolly be around a 1KT yield. No idea on the 100 Meg tho, not without doing a bit of a look up for data[/quote']

Oh. In that case it should go from 20d6K to 25d6K. Same principle.

[AirborneRob]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

Good deal. At first blush, a 5 Kiloton nuke doing 15d6 i figured a city buster ( which i dont think requires 100 Megatons) would be at least 25d6. Lol, i guess in the end it really doesn't matter since anyone taking a city buster to the face should have their molecules spread far and wide

[AmadanNaBriona]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

Usually the idea is supposed to be that each doubling of energy adds +1 DC. 5kt to 100Mt is roughly 2^2 kt to 2^17 kt, or 15 doublings. +15 DCs is +5d6K. If we started out with 15d6K, we'd want to scale it up to somewhere around 20d6K.

 

 

Oh. In that case it should go from 20d6K to 25d6K. Same principle.

Indeed, although I've always questioned that formula, mostly because defenses don't scale the same way

I'd probably tweak the MegaScale settings a bit, or a bit more than a bit, as the primary effect radius of a 10 MT, frex, is larger than almost the whole blast radius of a 5 KT.

 

Check this out, it's neat....HYDESim: High-Yield Detonation Effects Simulator

[AirborneRob]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

Indeed, although I've always questioned that formula, mostly because defenses don't scale the same way

I'd probably tweak the MegaScale settings a bit, or a bit more than a bit, as the primary effect radius of a 10 MT, frex, is larger than almost the whole blast radius of a 5 KT.

 

Check this out, it's neat....HYDESim: High-Yield Detonation Effects Simulator

 

That simulator is great, really puts it into perspective.

[AmadanNaBriona]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

That simulator is great' date=' really puts it into perspective.[/quote']

 

And you can target it wherever you want...

[AirborneRob]

Re: GAME RELATED: Anyone know the science behind an orbital nuclear burst?

 

And you can target it wherever you want...