Nerhesi said:
Matt - in game terms, it should be as per nuclear torpedo. Otherwise we're just asking for inconsistencies. Bigger nukes: larger area affected, not more dice of damage. I hope the giant trap is obvious if we start having icbms or nukes doing more game-term damage dice than a nuclear torpedo
As it is a 6dd (6d space scale) is also pretty much "why you even rolling?"
I see where you're coming from, but there are some issues with this approach.
The first is we need to factor in what a 'hit' means in space combat. I imagine it means that the warhead got close enough that, when detonated, it could inflict damage on the ship. It doesn't necessarily mean it physically made contact with the ship then exploded. The latter would be equivalent to a maximum roll on the damage dice.
In ground combat you're more likely to be in a situation in which several units (vehicles, people, anything you care about that could take damage) are close enough to the detonation to take damage, which given the ranges in space combat isn't something you normally need to consider.
Regarding damage effect though, a nuclear explosion in an atmosphere, and especially near the surface, can for many reasons be considerably more damaging than an explosion in space. In a vacuum the detonation creates a heat flash that bakes you on one side, then you get hit by super-heated material from the bomb itself which very rapidly disperses. On a planetary surface with an atmosphere the first effect is that the radiated heat flash from the explosion hits you directly, but also reflects off the ground and surrounding objects back at you from all directions. Next, the thermal energy from the explosion heats up the atmosphere and objects around you which then cook you for an extended period of time, again from all directions. The atmospheric pressure around the fireball also acts like a bottle containing most the energy from the explosion in the immediate area. The atmosphere also acts as a medium through which the shock wave of the explosion is conducted. It's like the difference between being briefly hit by a very fast high pressure water jet from a hose and being hit by a tsunami. Finally just when you thought it couldn't get any worse, convection then causes the fireball to rise up into the atmosphere, which creates a vacuum at ground zero, and surrounding debris is sucked into it at enormous speeds. If you're light enough and not nailed down, there's a reasonable chance you won't have to deal with that though because you'll get sucked up along with the fireball instead.
This is all one of the reasons why many physicists are skeptical of plans to use nuclear warheads to deflect asteroids. Nuclear weapons are certainly dangerous, but are an awful lot less effective in space than most people would expect. You can mitigate this a bit by carrying ablative material on the warhead, but every kg of that material you take reduces the performance of the missile in other ways.
Simon Hibbs
