Need help with Nukes and Mass Drivers

[garrowolf]

I am working on planetary scale combat for very high tech levels for my Nexus D20 system. I need to work out some details. I am working on nukes and trying to figure out the rules for those as well as mass drivers. Does anyone know of existing rules in a game for this? I need something that can scale up.
I know that some people just hand wave this part away as plot but I really want to work out this level of combat so I can have huge spacecraft fighting each other and hitting a planet. Some planets would have planetary shields and some would have only city shields. If the planet was hit with enough force from a mass driver/meteor then it would destroy the planet from underneath them. I actually have a way to generate wound levels/hp for planets so this is doable.
I would like to have some sort of formula that could help me with this if anyone knows of the correct ones.
Any help would be appreciated!
Thanks!

 

[Bluenose]

Earth Impact Effects Calculator. That should handle planetary impacts from mass drivers. There's a lot of nuclear bomb effects calculators around.

 

[garrowolf]

nice! Thank you!

 

[Dustin DePenning]

Not sure how complex damage is in your system, but games get a little silly when your dealing millions of d6 damage, etc.

Games like Rifts had MEGA DAMAGE. This existed on a completely different scale than other types of damage. Maybe this could help you sidestep the ridiculousness of linearly scaling weapons.

Maybe nuke damage is like "ATOMIC" damage. This automatically destroys anything that doesn't have ATOMIC HP, which is gained by using special armor or forcefields. As soon as you're out of ATOMIC HP, a single point of ATOMIC DAMGE destroys/kills you. Maybe nukes only deal a few points of atomic damage, so that way shields only need a few points, etc.

This pretty much exactly like MEGA DAMAGE, actually.

Anyway, you could then add a radius to damage effects, which would tell you exactly how much is completely wiped out when hit by a nuke.

 

[garrowolf]

Umm mega damage is one of the worst game mechanics in rpg history and is a bad example of scaling.

My system has scaling which reduces the numbers to reasonable levels for each scale. There are character, vehicle, ship, capitol, station, and planetary scale. Modern nukes are in the station scale (this also covers cities).
I am working on it at this high end because some scifi settings have weapons that do planetary scale damage. They also have defenses that can take that kind of pounding so I need to be able to scale up to deal with those ships.
I would never have a system that required rolling millions of d6. Actually in my system you don't roll for damage at all. Weapons have a base damage and your margin of success augments it.

 

[Dustin DePenning]

Sounds like you have it pretty worked out. You were just looking for hard science to inform the relationships?

 

[garrowolf]

Basically yes

 

[Umbran]

Makign a biosphere uninhabitable and killing all the current people within it is within the realm of nuclear weapons.

Outright planet-busting gets a little hinkey with hard science. As in, "this takes so much energy that you can't easily do it".

 

[tomBitonti]

This is a rather nice supplement if you want to get more data about weapons:

http://www.amazon.com/3G3-Guns-Weapon-design-Edition/dp/0943891191

You will want to know some math and physics to get the best value.

If you can get into orbit and can redirect asteroids or meteors (even small ones) then you can start getting rather high energies. Redirecting an asteroid seems possible for low energy requirements. Although, getting to target could take many years.

At large scales, e.g., megatons and higher, there are interesting considerations. For example, for an unshielded city, you want multiple warheads (MIRV) for an area bombardment, rather than one big nuke.

One of the lessons from 3G is that lasers and kinetic energy weapons generate a lot of the same effects, with lasers causing a flash explosion (on a person) which is about the same as a bullet impact in terms of damaging effects, both causing damage through hydrostatic shock.

Another lesson (generally) is that nuclear weapons in space have different effects because of the lack of the atmosphere. Radiation travels a lot further, making the radiation effects on an unshielded person much worse at greater distances than in a planetary atmosphere.

A question will be whether you want the results to "feel" correct from a pulp/genre standpoint, or if you want more physically realistic results. Realistic results very possibly won't make for much of a game.

Thx!

TomB

 

[garrowolf]

I finally found a table that covers what I was looking for!
http://www.projectrho.com/public_html/rocket/usefultables.php#id--The_Boom_Table