[Spaceships] Using different sized spaceships

[raniE]

I'm planning on running a TL10^ campaign where the PCs will be piloting a number of different spaceships in combat. These would be capital ships not fighters, so they would not necessarily appear all at the same time but probably at different points during the campaign. A snag I ran into however was the combat system in Spaceships, specifically the damage and damage reduction numbers and how these scale.

I'll start from the basis of a SM+14 ship, giving it hardened nanocomposite armor and a hardened light force field that gives the ship 900 points of hardened dDR. A 100 GJ particle cannon or x-ray laser (a SM+14 medium battery) will do 2d*50 dDam with a armor divisor of (5), typically dishing out 50 points of decade-scale penetrating damage per shot that hits, assuming an undamaged force field. That is 7.1% of the ships total hit points.

A SM+13 ship built in the same way has 650 points of dDR. A 30 GJ x-ray laser or particle cannon (at short range or less) will typically deal out 0 points of damage per hit, assuming an undamaged force field. That is 0% of the ships hit points. The percentage of ships hit points destroyed by the same weapon against the same armor, adjusted only for size, fluctuates by SM, going up and down and back up again like a rollercoaster as one moves from size to size. With this setup it goes from 0%, at SM+7 and +13, to 11.6% at sm+15 (assuming the dice roll 11 and not 10.5).

So, how do I keep rough parity between ships at different size modifiers fighting each other? Or is the difference not noticeable in play (since some of the ships end up ealing no penetrating damage at all I doubt this is the case though)?

[Ulzgoroth]

Huh. That's really strange. For some reason, the energy weapons scale 10-15-20-30-40-60-100 rather than 10-15-20-30-50-70-100.

That seems like a glitch to me. They both seem like they're supposed to be a 10^(1/6) geometric series, but the armor sequence is the better approximation.

[raniE]

Originally Posted by Ulzgoroth

Huh. That's really strange. For some reason, the energy weapons scale 10-15-20-30-40-60-100 rather than 10-15-20-30-50-70-100.

That seems like a glitch to me. They both seem like they're supposed to be a 10^(1/6) geometric series, but the armor sequence is the better approximation.

So, what damage rolls would you substitute for the broken ones to fix this? And which are the broken ones? The ones doing 0-4% damage, or the ones hovering around 9%?

[Ulzgoroth]

Originally Posted by raniE

So, what damage rolls would you substitute for the broken ones to fix this? And which are the broken ones? The ones doing 0-4% damage, or the ones hovering around 9%?

Well, if you want to assume it's a mistake, you'd change the 10 and 30 MJ, GJ, and TJ guns. I don't know if it makes any difference for the 10 and 30 KJ guns when working on the decade scale, fractional dice give me trouble.

Each of those guns starts with a 4d or 6d. Up that to 5d and 7d, and the armor-guns relation ought to become a bit more constant.

[Langy]

The problems are at 10MJ, 30MJ, 10GJ, 30GJ, and 10TJ and 30TJ.

Instead of their dDamage being 4d, 6d, 4dx10, 6dx10, 4dx100 and 6dx100, they should be 5d, 7d, 5dx10, 7dx10, 5dx100 and 7dx100 respectively.

The 3kJ through 30kJ figures should all be one higher than listed as well.

Their dDam2 figures should be twice that.

[raniE]

Originally Posted by Langy

The problems are at 10MJ, 30MJ, 10GJ, 30GJ, and 10TJ and 30TJ.

Wait, so 1 GJ and 3 GJ are fine? Then why does a 1GJ x-ray laser against an SM+10 ship with the above mentioned armor do, on average, 2% of the total hit points of the ship in damage, while the 3 GJ x-ray laser does 7.5/10% (depending on if you want 10.5 or 11 to be standard) of a SM+11 ships hit points in damage on an average hit?

Originally Posted by Langy

Instead of their dDamage being 4d, 6d, 4dx10, 6dx10, 4dx100 and 6dx100, they should be 5d, 7d, 5dx10, 7dx10, 5dx100 and 7dx100 respectively.

The 3kJ through 30kJ figures should all be one higher than listed as well.

Their dDam2 figures should be twice that.

I'll have to look at these numbers tomorrow, I have to sleep now.

edit: Ok, so I checked it before sleep, I believe you missed 1 MJ, 1 GJ, 1 TJ etc. Thse should also have their damage dice adjusted. Actually, any damage that is 1, 10 or 30 KJ, MJ, GJ, TJ or PJ probably needs to be adjusted upward.

[Ulzgoroth]

No, we didn't miss them. Those have much smaller rounding errors. The 'perfect' sequence is:
1
1.47
2.15
3.16
4.64
6.81
10

Here's the math involved, using 'perfect' numbers above, and the rounded ones below.

armor	shield	total/3		dice	average		net average	HP	fraction
46.4	147	64.47		21.5	75.25		10.78		147	7.34%
68.1	215	94.37		31.6	110.6		16.23		215	7.55%
									
50	150	66.67		20	70		3.33		150	2.22%
70	200	90		30	105		15		200	7.50%

The difference is that in the SM+11 case, the rounding pretty much cancels out, whereas in the SM+10 case it favors the defense in every way that it can. You're going to have to tweak finely and put up with some ugly numbers if you want to get around it, and I don't know how much it really matters.

And the way it breaks is an artifact of your scenario. If you change the armor divisor, you change the whole picture. And it's a pretty odd scenario. I'd transfer a warship architect who built ships with the protection you describe to salvaging destroyed fission reactors. The armor's a criminal waste of mass. If you had another shield generator instead, you'd laugh at anyone trying to use a medium battery on you.

[Langy]

The 1MJ,GJ,TJ,PJ weapons follow the 10 15 20 30 50 70 100 progression that armor follows. The ones I mentioned do not.

[SuedodeuS]

Originally Posted by Ulzgoroth

And the way it breaks is an artifact of your scenario. If you change the armor divisor, you change the whole picture. And it's a pretty odd scenario. I'd transfer a warship architect who built ships with the protection you describe to salvaging destroyed fission reactors. The armor's a criminal waste of mass. If you had another shield generator instead, you'd laugh at anyone trying to use a medium battery on you.

Actually, Spaceships mentions that you may only have one shield generator in use. Of course, replacing the light generator with a heavy would certainly be a very good idea.

To the OP, keep in mind that X-ray lasers aren't normally available until TL 11, meaning they would probably be out of reach for your setting. Particle beams can still be problematic, but ships thus armed have to generally get a step closer to be able to attack than those using visible lasers (and a good deal closer than those using UV lasers), and they also suffer a bit of an Acc penalty. Could be interesting to see how useful it is to make that trade-off. If you have X-rays available, however, they're going to be the dominant weapon. As in, everything but dedicated point-defense (which would probably use VRF Improved Visible-Light lasers) is going to use them.

[raniE]

Originally Posted by Langy

The 1MJ,GJ,TJ,PJ weapons follow the 10 15 20 30 50 70 100 progression that armor follows. The ones I mentioned do not.

and yet they still produce wonky results.

As for the design of the ship, any ship using a warpdrive has a drivefield functioning as a light force screen around it. There is no possibility to add more screens, so armor's the best there is at increasing dDR.

The numbers do remain wonky if the situation is changed though. Let's say a damage reduction of (5) instead of (3), same damage (nothing was hardened I guess). That leaves the 1 GJ weapon doing 20% damage against the size 10 ship, and the 3 GJ doing 25.5% damage against the size 11 ship. The discrepancy also remains if the scenario is UV-lasers against one layer of hardened armor only, being 13.3% vs 17.5% (5.7 vs 7.5 hits to bring the ship to 0 hp).

These other examples are perhaps not as bad as the original one, but the problem remains nonetheless. Adding a +2 to the dice (so the dDamage would be 4D+2*5) sems to take care of things smoothly for 1 GJ for the most part, leaving smaller gaps compared to 3 GJ in the scenarios I checked compared to leaving it alone.