Real Space Combat Help:

I think Railguns/ Mass drivers can be extremely effective considering 
you can tailor the ordinance you can fire. For instance:

1. Stealthy Penetrator rounds!
2. Stealthy missiles that flip on their drives just outside the 
target's defensive envelope!
3. Bomb pumped x-ray lasers!
4.Big Rocks!
5.Frozen Chickens!

In combat I think that you would lay down a "probability pattern" of 
most likely hits. The current first generation Mass drivers GE is 
testing for Main Battle tanks is performing at 5400 FPS (feet per 
second) muzzle velocity with a kinetic penetrator round. Assuming 
your Starship has a Railgun that is 10 times more efficient (not 
unreasonable, I think) in space you should be able to get fractional 
C velocities since there is no Atmosphere or Gravity to interfere. 
The thought of being hit by a 1 kilo Frozen Chicken moving at 5% of C 
is enough to give ME the willies! 
Later.....
Mike Wikan
Game Design\Conceptual Art
n-Space, Inc.
A Producer of 3D Entertainment Products