So, sometime, there comes a point in a young mans life where he sees something that someone says in the internet that is WRONG. And, by golly gee, he simply cannot rest until he has corrected this grievous error. That time, ladies and gentlemen, is now.
So I've seen some posts other places on this forum where occasionally people address 'realism' in the game world in an off-handed sort of manner, and it seems to be the general consensus that only 'beam' type weapons would have a practical use in space, because recoil would prevent any other weapons being used practically.
Well ladies and gentlemen, I am sufficicently bored and pathetic to take issue with this! It is true that every action ahs an equal and opposite reaction, and that this makes ballistics in space problematic. However, there is a relatively simple work around to this basic concern.
The most common proposed ballistic space-weapon is that of the mass-driver, or railgun. Given the preciousness of oxygen, nobody wants to use conventional ballistic weaponry in space, as most of it requires the oxidation of some sort of propellent. So instead we use magnetic fields. Now it is true that launching an object of significant mass at absurdly high speeds away from a spacecraft would typcially cause your craft to move in the opposite direction. But, never fear! Engineering is here!
By enclosing your railgun launching system in a two-layer system, you can have a magnetic counter-acceleration system to dampen and effectively neutralize the recoil. This two layer system would conists of some sort of ferrous outer coating, and beneath that, a faraday cage, to prevent your magnetic fields from interfering with one-another. The outer counter acceleration would simply move the entire firing operatus forward with precisely the same force that was being applied to the projectile being launched. This neutralizes any effect the firing would have on the ships momentum, and allows you to maintain course and heading with little disturbance while firing away to your hearts content.
But wait you say, this system sucks up twice the amount of energy, and beam-weapons are already more efficient! Well, it really depends on what sort of protective countermeasures your enemy might be using. By employing an ablative coating, ship may use a lsers own destructive power against it by using a cloud of vaporized material to reflect the energy from incoming laser fire. Also, shield technology, in whatever form it takes, might be more effective at disabling or dampening beam weaponry. However, slamming heavy objects into other heavy objects more or less always causes a dependable amount of destruction.
In summation, railguns in space are totally do-able, and super-cool.