How about lasers?
They would be a logical next step thematically but also make sense in terms of design and balance. Lasers require LOS, which makes them functionally different from the existing missile weapon. However, unlike
torpedos missiles they will not (I assume) require a consumable. Perhaps, like in the real world, higher frequency waves would carry more power than lower frequency waves of the same amplitude, but attenuate more quickly. A simple set of functions that crudely approximate the real behavior of light could be enough.
Perhaps something like these:
power = frequency * amplitude
range = amplitude / frequency
beam duration = frequency * some coefficient
damage = (distance / range) * ( hit duration / beam duration ) * power
These are all linear functions, of course. One could make them logarithmic, parabolic, whatever. They could easily be tweaked to be balanced within the game with a few coeffieicents thrown in. One might, for example, have a coefficient in the calculation of dispersal that took into account the density of nebulae, which would be rather realistic. Balancing laser type weapons with the existing
torpedos missiles would be a matter of using the correct coefficients, probably focusing on energy cost and charge time. It’s also desirable to keep them simple so they’re accessible to the player.
I see the biggest issue being ensuring the appropriate level of detectability so as to not make the user of a such a weapon an invisible, unfettered merchant of death. Using the jump drive approach with waste heat makes a lot of sense given the massive capacitance a laser power supply would need. I’d also assume that the natural dispersal caused by some of the photons interacting with random gas particles or other bits of crap in space might be justification for it to leave some kind of ‘signature’ that could be drawn as a line onto the NAV.
For gameplay (and players) the interesting part would come in applying these principles to one’s tactics. Players would fine tune their laser weapon system for a given scenario. Perhaps a computer would caculate a firing solution based on user specified requirements, adjusting some attribute of the wave to satisfy another. One would no doubt have to charge the weapon first, and so there’s a lot that could be done with capacitors, either as expansions or variations in makes/models. Addtionally, one could limit the frequencies a given model was capable of emitting, or maybe the efficiency of the charging apparatus… Perhaps have effects realistic to the true EMF, such as thermal lasers to heat up a ship, or gamma lasers disrupt systems… (why not make use of the ECC in those consoles? haha)
Of course, these details/expansions of the basic concept are all just ideas I’m throwing out for fun. It’s best to keep things simple.
Now, whether to make them unrealistic enough as to be optically visible, or impossible to evade with reflective surfaces is left to your judgement.