[seasalt]

Out of many of the settings in the old 3e 'Alternate Earths' supplement, the 'Caliph' setting seemed like an especially interesting one, especially in view of the real-world international culture war today. It's interesting because it is clearly "alternate history wank" for an ideology I strongly disagree with, yet it seems to have been intentionally set up in such a way that the "apostate" faction, the Jamahiriya, can easily be treated as the heroes.

But anyway - I dunno if I'd ever run it but it got me to thinking how an interesting military tech base for this setting could be fleshed out, especially if you want to go beyond the basics of "little squads in power armor running around trying to capture the robofacs". One of the illustrations shows a dogfight between a couple of futuristic jets and that captured my imagination while slacking off at work the other day.

First off I think a basic tweak to the setting is needed, of reining in the reactionless drive "thrusters" a bit. The problem is that if every civilian car has a high-thrust reactionless drive built into it, then literally EVERY vehicle in the setting, even individual suits of power armor, suddenly becomes a planet-killing WMD. Granted, the looming threat of WMD and global extinction is a major theme in the setting, but it shouldn't be quite THAT easy! At least make the warring nations need to build some antimatter nukes or killer nanite plagues or something!

I think the simplest solution is to say that the true "reactionless drives" are tachyon engines which have very low thrust and only work in space, meaning that launching one gives any spacecraft in the solar system plenty of time to intercept it and kill it before it reaches relativistic planet-cracking velocities. Wheres all of the flying cars and battlesuits and such are just using air-breathing fusion powered turbofans. If you have backpack-sized cold fusion power plants, you can build all the flying cars, flying tanks and power armor you want, no need for planet-killing high-acceleration reactionless drives inserted into every little jalopy. Honestly, I'm tempted to just say remove the reactionless drives altogether and say that the robotic probe ships carrying "stargates" to other solar systems are using highly efficient antimatter thrusters that still require reaction mass. That would be hideously expensive but the fact that there's a glut of resources is a major part of the setting already.

Anyway. The setting emphasizes that it's all about airpower and I think this kind of high-tech air combat could be really interesting. However the details are outdated and based on 3e, as it says everything uses "X-ray lasers", which don't work in atmosphere.

So what would these late TL 9/early TL 10 fighter jets look like? GURPS is... decent as a vehicle combat game if you want it to be, it handles it better than most other RPGs (which is damning it with faint praise, granted). The "Action 2" chase combat rules seem like they'd work ok. The setting writeup mentions that everyone is using neural interfaces to have sufficient "reaction time" so presumably everybody has got Enhanced Time Sense. It also says that combat robots aren't being used because they are too vulnerable to being hacked so all the vehicles will be piloted.

I imagine that fighter jets would be mainly armed with small semi-autonomous laser turrets for point defense, and maybe one big spinal laser to be used offensively. So, how can we make this both vaguely realistic and interesting so that it isn't just a contest of who has the bigger, longer-ranged gun?

I think the key is in heat-shielding. Basically, every fighter would have super-efficient cooling all over its body, which they'd need to anyway if they have a friggin' fusion reactor in there, that is gonna produce a lot of heat, not to mention lasers themselves are putting out crazy amounts of waste heat. So the same sytems keeping the planes from melting themselvees into slag would also be a powerful defense against lasers. A powerful enough laser could vaporize surfaces into plasma fast enough to breach through it, but it'd still be a potent defense.

In game terms, I'm thinking that each aircraft would have a "shield", except instead of a full on energy shield (which seems to be mostly limited to fixed locations or large spacecraft) it has the limitation that it only functions against lasers. And, firing the craft's own laser weapons or using the afterburners causes "damage" to the shield, which regenerates a certain amount of points each turn. And the one spot not covered by this "shield" would be the heat radiators, which I envison being on the back edge of the wings, which gives an excuse for old-school dogfighting to try and get behind the other guy and lase his radiators.

Then of course, there's missiles. The TL9 "Genius Missile" from high tech is probably ubiquitous and could be launched at almost infinite ranges, since it's smart enough to perform its own target identification and try to evade point defenses. I envision that a basic tactic might involve hitting an enemy with lasers first, to overheat him and force him to turn away and flee (angling his most powerful fixed-forward weapon away) and them fire a missile or two to finish him off. Rapid-firing gyrojet "guns" would be the secondary weapons.

I think that conventional guns would probably not see much use, because even if they're electrothermal, the range will be way too short compared to lasers, and a big enough shell to do much damage will get shot out of the air before it can hit. Since calculating the penalties each and every time a projectile is incoming would be ridiculous amounts of bookkeeping I'd just look at what attack bonus a particular weapon gets with a -20 "shooting the projectile" penalty as per the basic rules, and assign it an impromptu "block" based on that to use against micro-missile swarms, with each laser turret allowing another block per turn. And as for bigger genius missiles, which would be armored and have countermeasures of their own, do attacks against them the old fashioned way. This creates a tactical decision as the pilot has to choose between shooting at the enemy aircraft while trying to dodge missiles, versus focusing on shooting the missiles down and letting the opponent rake him with lasers.

What are your thoughts on what air combat in a setting like this might look like? I think thematically, it fits the cultural aesthetic, since nimble fighters are a bit like medieval horsemen - closing in to threaten the enemy, then backing off, even using turreted lasers and mini-missiles to do a bit of a "parthian shot".