GURPS put the power of their lasers in the description (the smallest being 43Mj). There has to be some mechanism that relates to the "pew-pew" idea, or else you'd never be able to keep the beam on the same place to do any damage. Why? Because you can have ships that are tens of thousands of kilometers apart, each doing their own evasive dance to avoid the fire of the other. Keeping the beam on a specific spot for any length of time is going to be quite difficult. The beam and pulse lasers have different firing modes, but essentially they are both trying to just hit the target downrange.
However you want to assign the tech is fine with me. But they are still going to be quite close to light speed weapons because they are, in fact, weapons made up of energy, energy traveling at, or very close, to the speed of light until they begin to lose their focus and spread their energy out to a point where they are no longer dangerous.
Reynard said:
That would also explain laser detectors and prismatics vs. laser weapons in Striker and The Vehicle Handbook too. Laser hits and begins to burn. Poof, a cloud of aerosol or smoke to disperse the beam. I believe this is why a pulse laser isn't affected by sand while other high energy weapons burn through sand on the way to a target.
This is a reasonable explanation. The one problem is that if the target simply moved the beam would no longer be on the same point to burn through. It then becomes a question of just how agile a starship might be while performing both offensive and defensive fire. Too much jumping around and your own shots will miss their mark.
It makes you wonder if starship combat would be akin to what WW2 tanks engaged in - most tanks stopped to stabilize and fire at targets any distance away. Naval ships, though, did not and would fire on the move while the enemy was on the move too. Though long-range gunfire was sometimes not the most accurate. But I don't think the battlewagons would be doing much maneuvering when they fired because threw off their own gunners. Anybody more knowledgeable on naval gunfire for the golden age of sea battles??