Appropriate skills for DEWs

[Varyon]

By GURPS default, Directed Energy Weapons (DEWs) use Beam Weapons, with required specialization into Pistol (for one-handed), Rifle (for two-handed), and Projector (for those that spread as a cone or similar). The last honestly seems like it should be something like a Familiarity or Technique of the others (much as the Pyramid #3/65 gun article replaced Guns (GL) with a Payload Technique), but we'll come back to that.

My purpose here is to explore the differences between the Beam Weapons and Guns skill, and see if there are some weapons that traditionally fall into the former that would be more appropriate for the latter. From what I understand (influenced heavily by some of lwcamp's posts and articles), for a weaponized laser to be effective at range it needs to be set such that the beam is focused exactly at (or at least very close to) the range at which the target is located. This means the weapon must "focus" on a target - actively by using a rangefinder, passively by using technology comparable to a modern camera's autofocus (or even with the user manually adjusting the focus) - to be effective, as otherwise it's just briefly shining bright-but-unfocused light on the target. This is different from the way a firearm is used, hence being a different skill.

That's for realistic lasers, but the way they are typically depicted in fiction has them as just a single focused beam coming from the weapon. This seems doable, and avoids the need to focus above, but is going to greatly reduce effective range for the weapon. Electrolasers are likely to use this methodology, as you don't need - or want, really - a focused point on the target, but rather a nice, ionized channel to conduct the current. Microwave Area Denial (MAD) weapons are likely to use this scheme, as are any other cone weapons - although they could get better range (in exchange for being an AoE effect on the target rather than a cone leading up to it) by using variable focusing. Sonic stunners probably use variable focusing, but don't necessarily have to. Particle beams are likely to use variable focusing, although the way they are depicted in fiction is, again, a single focused beam coming from the weapon.

For superscience weapons, in many cases either scheme could be used. As cones, neural weapons seem by default to use the single-focus scheme, but could be converted to longer-range AoE weapons by using variable focusing instead. Sonic screamers are in a similar boat. For plasma weapons, these are clearly single-focus, both for flamers and plasma guns, and it's difficult to imagine a variable-focus variant with the weapons being so similar in nature to flamethrowers and firearms, respectively. Gravity weapons seem most appropriate as variable-focus weapons, as do disintegrators and conversion beams, although one can imagine shorter-ranged single-focus variants. Field-jacketed beams are almost certainly single-focus. For weapons outside of UT, Star Wars blasters (which seem comparable to most soft scifi DEWs) are clearly single-focus, while the "Little Doctor" from Ender's Game and its sequels uses variable-focus.

I would strongly suggest that the Beam Weapons skill is appropriate for weapons using variable-focus, while those using single-focus handle more like Guns. A Beam Weapon DEW with an area of effect, such as a dazzler laser or similar, seems somewhat-comparable to the Payload Technique for guns. With that in mind, I would suggest a new Technique for both Beam Weapons and Guns:

Projector						Hard
Default:  Prerequisite-2
Prerequisite:  Beam Weapons or Guns; cannot exceed prerequisite

This Technique allows you to buy off the -2 when using a DEW that
produces an area of effect (for Beam Weapons) or projects a cone
(for Guns).

Note this effectively gets rid of the Beam Weapons (Projector) skill.

The Burst-Fire Technique probably isn't necessary for most DEWs, due to lack of recoil, but I'd be tempted to leave it in (particularly because many superscience DEW's do produce recoil).

The Gunner skill would follow the above scheme - Gunner (Beams) for variable focus DEWs, Gunner (Cannon) for single-shot, single-focus DEWs, and Gunner (Machine Gun) for multi-shot, single-focus DEWs. Actually, looking at Gunner, it seems like it should probably just be Beams, Catapult, and Guns (rolling together Cannon, Machine Gun, and Rocket), with appropriate Familiarities and Techniques, but I digress.

What does the hive mind think? Additionally, what sort of mechanical difference should there be between single-focus DEWs (DEW Guns) and variable-focus DEWS (DEW Beams)? The latter seem like they should be at least a bit more expensive (and perhaps marginally heavier, due to having a large aperture) and possibly require an Aim maneuver before being able to fire, but would have greatly improved range. The question is, how much more expensive (if at all) and how much of a range boost? Playing around with lwcamp's Burninators, and assuming the UT lasers use red light, I'm getting aperture diameters around 1000x the minimum (which I take to be appropriate for single-focus) to get comparable 1/2D ranges (Luke's system handles Max quite a bit differently). As range appears to scale linearly with aperture diameter, this implies single-focus DEWs would have roughly 1/1000th the range of variable-focus ones (and conversely, variable-focus DEWS have 1000x the range of single-focus ones). That seems a bit excessive... but perhaps it isn't? Even so, it seems like the effect wouldn't be quite as pronounced when comparing a cone DEW to an AoE DEW, but I may be mistaken. What sayeth the hivemind?