[Spaceships] Weird Numbers

[Mailanka]

So, unable to sleep and still tinkering with how combat should work in my space opera, I dig out a spreadsheet, GURPS Spaceships, and start working out some math. It bugged me that while there was an article for the square root of destruction (making beam weapons more powerful) there was no comparable one for tuning down the damage of guns (the cube root of destruction).

Some things that popped out at me: The base beam damage is the cube root of the battery size x1. It's pretty much straight across the board.

The HP of every ship is inflated. Not by much, but Pulver has generously rounded up in each case.

Finally, ballistic damage has nothing to do with the square root of anything. It's the bore size (in cm) x 5. Look for yourself: 2cm guns deal 3d damage. That's an average of 10 damage, or 5x2. 10cm guns deal 3dx5. That's an average of 50 damage, or 5x10. 112cm guns deal 6dx28, that's 560, or 112x5 (note that this is using the GURPS formula or "2d = 7, 3d=10" rather than 1d = 3.5)

I imagine this is because these guns are HIGHLY abstracted, moreso than beam weapons. We have tonnage translating into bore size, which makes no real sense. There's no particular reason that a 1.5 ton gun HAS to be 10cm in bore size. In fact, that actually doesn't work with EM guns, which tend to have much smaller bore sizes with similar weights. Furthermore, boresize only has so much impact on damage: A 10mm rifle does more damage than a 10mm pistol, because it has a longer barrel and likely more charge behind the bullet. Thus, rather than letting us fuss with barrel lengths, the type of bullet and the bore size, we just get "Look, a 1.5 ton gun is 10cm and does 50 damage on a d-scale, approximately.

This has an interesting side-effect. If you find guns are doing far too much damage, you might be playing with small ships. Even before we get into relative velocities, a 1.5 ton gun fits on a 30 ton ship (SM +5). It deals about 50 damage, and the ship only has 20 HP. Even with three layers of exotic laminate, some of that damage is going to get through (especially with an armor divisor of 2).

But a 150,000 ton gun with a 56cm barrel on a SM +15 ship deals 280 damage while the ship has 1,000 hit points. A single layer of nanocomposite will stop this dead without an armor divisor, and two will stop it with even with an armor divisor of 2, never mind exotic laminate.

Even when you account for relative velocities, as you scale ships up, ballistics becomes less and less important.

Beam weapons don't have this problem. They scale with the ship, and deal just slightly under 1x HP per shot. Thus, an SM+15 beam cannon, or an SM+20, or SM+100 beam cannon does the same proportional damage to a ship of the same size, always.