Comparison of Space Beam Weapons in GURPS Vehicles, 2 Ed.

[Rupert]

Originally Posted by Curmudgeon

Recently, I started doing some conversions of FGU’s Space Opera to GURPS, specifically Starships of War, Vol. 1. If you haven’t bought the book, there are some potential problems with using it as written. All star nations in the game (so far, volume one covers four of the star nations and there are at least nine other star nations that have been mentioned) use Nova guns (pulsars in GURPS Ultratech; antiparticle beams in GURPS Vehicles, 2nd Ed.) and MegaBolts and StarTorps (which have ratings that translate into Nova fire for damage). The only differences in armament is the calibre used (which affects damage and range) and the number of weapons mounted. The issue with that is that the author had some blatant bias towards the starnations. On any given class of ship, the Terran Union has more weapons and bigger caliber weapons than any of its opponents, followed by the Azuriarch Imperium, Merchantile League and finally, the Galactic Peoples’ Republic. Additionally, some classes of starship don’t appear in some of the star nations’ inventories.

Funnily enough I've been noddling around with this for some time, too. I have the old "Seldon's" series Fred mentions. And yes, the Terrans are simply richer and a bit more advanced than everyone else, so they make gold-plated ships, and match everyone else's ship types. I doubt they actually know shere some of their ship types actually fit into their naval doctrine.

Below that it's not quite so clear-cut - some Mechantile League ships are better than their Azuriach contemporaries in some areas. The GPR, being Space Soviets, build them cheap and cheerful (but some of their ships have some features that can surprise).

I was going to treat Nova Guns as some kind of laser and play with Gravitic Focussing options and exact type until I got the range and damage balance I wanted. StarTorps are just missiles. MegaBolts would need some special penetration rules. I was intending to use Spaceships - maybe. Or maybe VE2. Or maybe Fire, Fusion, and Steel (Traveller: The New Era's design rules).

For movement I was going to go with pseudo-velocity, with the surrounding techno-babble including the TISA drive being at least partly inertialess, thus allowing the massive accelerations without turning everything in the ship into paste.

The UV laser is surprisingly good. At 1,061,100 km, it has the longest range of any beam weapon and its FP 31 is decent enough. The rainbow laser is marginally less effective with a range of 1,000,500 km and FP 29. Where the rainbow laser kills the UV laser is in cost and weight. At $22 million rainbow laser costs less than half as much as a $48 million UV laser and weighs only 650 tons instead of 950 tons. Most starship designers are willing to make the tradeoff and mount rainbow lasers instead of UV lasers, but their ships do need heavier armor to get within range of the odd ship that mounts UV lasers.

Rainbow lasers lose range and penetration in a vacuum (UT116) - x1/10th range and no penetration modifier. EDIT - only relevant if you're converting all the stats and behaviour to 4e, I suppose (and doing that involves having to make some choices about how to convert lasers).

Have you experimented with giving the types with high damage and low range one of the extended range options?