Making EM Guns Viable in Space Combat (3e)

[Polydamas]

Originally Posted by David L Pulver

SPACESHIPS is a simple system, and so is GURPS when it comes to edge cases.

SPACESHIPS doesn't treat Whipple Shields very much because I didn't come up with a good model for them. (The logical approach is high volume ablative DR, but how effectively they are against non-hypervelocity attacks has to be considered as well). Also, because they effectively trade volume for protection, they don't work very well in SPACESHIPS. The system keeps some degree of simplicity by by abstracting out volume in favor of mass, as that worked best with my desire to present a simple but fairly realistic rocket equation integrated into the rules for fuels and drives. (If you want a system that does the other thing, and abstracts out mass, see most versions of TRAVELLER). However, the tradeoff is that SPACESHIPS has trouble with things that are volume-centric -- and Whipple Shielding armor is most fundamentally about trading volume for protection. Trying to solve this on top of adding a new model for hypervelocity impact damage was just a bridge too far. But yes, I do regret not covering this element in more depth, and if I find a simple way to do it and revisit the SPACESHIP rules, I would consider changing the rules to adapt something like this.

There are, however, dangers with messing too much with the basic damage mechanics of GURPS, since no one (for example) would want their high DR superheroes to have all the DR ignored when a meteoroid or equivalent weapon system hit them...



As a result, integrating and balancing the tradeoffs for it in a mass-centered system somewhat more complicated, and with space limited, I chose not to cover it. The other reason is that whipple armor is largely only tested and graded against micro-meteoroid type impacts, and there is limited available data on how well the armor will stand up to, say, energy beams, nuclear detonations, or larger caliber impacts, how compatible it would be with streamlining, etc. Finally, GURPS has rarely bothered to treat hypervelocity penetrations as anything other than high armor divisor impacts, so creating a whole new system in a book with limited space seemed ill-advised! I did consider a subsystem for this, but not in time to develop and playtest it.

Thanks for taking time to comment. Regarding the fact that post-1950 armour technologies such as Chobham or Whipple Bumpers take up more space than traditional hard dense homogeneous armour, it seems like that is a good in rules centered around mass instead of volume. It avoids the gotcha about "what if a spaceship has a high percentage of its mass as armour, shouldn't it be smaller, didjaeverthinkaboutthathuh?"

Regarding what has or has not been tested or modeled, I have a folder of studies which I will go through and summarize on my site sometime this year. While the US, Russian, and Chinese militaries probably keep their studies of modern armour technologies vs. weapons secret, I want to see what the actual studies say and what scenarios they have covered rather than trust some forumites.

I think Agemegos has a point that if GURPS were ever redesigned, it would be a good idea to eliminate Armour Divisor and Hardened, let damage be armour penetration, and just allow a wider range of damage multipliers eg. 1/10 for attacks which currently have AD (10) WM 1.0