Need advice designing a fair ultra tech gun.

Varyon · 02-08-2016, 09:30 AM

First off, the space suit DR. Is this split DR meant to represent different DR in different locations (as seen with rigid armor) or different DR against different attacks (as seen with flexible armor)? If the former, spikes might have less issue getting past armor away from the Torso and Skull, and shooting those locations might be able to carve away some of the armor with the follow up explosions (basically, pump the chest full of spikes, blow them up, then your next round of spikes have a better chance of reaching the juicy center). If the latter, you'll want to consider which applies to the Imp spikes you're throwing at the targets.

Secondly, the users probably don't need to worry much about the explosions. A 15mm HEC (why would a mining tool be designed to fragment?) warhead is doing* 2d cr ex. That's an average of 7 damage at ground zero, which is less than half the lowest protection of their armor. Maximum damage is 12, which is still less than their armor's protection At 1 yard away, damage is divided by 3, dropping those to 2 and 4, respectively. 2 yards out those become 1 and 2, and at 5 yards away (only -2 to hit) they aren't feeling more than a light push from the explosion, even without armor. The explosive's real effect, in this case, is that if it gets past armor it does triple damage, ripping up the target pretty well (and, as noted above, you can use it as justification to ablate away at armor it fails to penetrate, provided it gets stuck; note this is precisely what it would be designed to do as a mining tool).
*I should note here the actual damage depends on what TL the ammunition is. If it's TL 9, the above damage is appropriate. At TL 10 it changes to 2d+2, and at TL 11 it becomes 2d+4 or 3d. It's still not getting past armor on its own, however.

For stats, personally I'd go with the Gyroc Carbine, dropping the shots to 6(3i), the RoF to 1, and maybe making it Bulk -4. Damage would become 6d imp. Price would stay the same - the drop for a more simplistic design is countered by the need to handle finicky ammunition and the ability to broadcast the detonation signal. The spikes are probably heavier and would cost more than a micromissile; I'd eyeball them at WPS 0.2 and CPS $75 or so. The increased weight should drop their range; going to 1,000 is likely (not that that's likely to matter in a horror campaign). They still need space to get up to speed, as usual, so keep that in mind when the target is within 10 yards (which is likely to matter in a horror campaign).

If you want better precision, you may be interested in picking up GURPS Vehicles, which has a nice chapter on designing weapons. It's a 3e product, so some of the stats will need converting, but damage, weight, and range are consistent between editions. You'll want to figure out MinST, Bulk, and Rcl based on similar weapons, and for 3e Acc is typically double 4e Acc.

02-08-2016, 09:30 AM	#7
Varyon Join Date: Jun 2013	Re: Need advice designing a fair ultra tech gun. First off, the space suit DR. Is this split DR meant to represent different DR in different locations (as seen with rigid armor) or different DR against different attacks (as seen with flexible armor)? If the former, spikes might have less issue getting past armor away from the Torso and Skull, and shooting those locations might be able to carve away some of the armor with the follow up explosions (basically, pump the chest full of spikes, blow them up, then your next round of spikes have a better chance of reaching the juicy center). If the latter, you'll want to consider which applies to the Imp spikes you're throwing at the targets. Secondly, the users probably don't need to worry much about the explosions. A 15mm HEC (why would a mining tool be designed to fragment?) warhead is doing* 2d cr ex. That's an average of 7 damage at ground zero, which is less than half the lowest protection of their armor. Maximum damage is 12, which is still less than their armor's protection At 1 yard away, damage is divided by 3, dropping those to 2 and 4, respectively. 2 yards out those become 1 and 2, and at 5 yards away (only -2 to hit) they aren't feeling more than a light push from the explosion, even without armor. The explosive's real effect, in this case, is that if it gets past armor it does triple damage, ripping up the target pretty well (and, as noted above, you can use it as justification to ablate away at armor it fails to penetrate, provided it gets stuck; note this is precisely what it would be designed to do as a mining tool). I should note here the actual damage depends on what TL the ammunition* is. If it's TL 9, the above damage is appropriate. At TL 10 it changes to 2d+2, and at TL 11 it becomes 2d+4 or 3d. It's still not getting past armor on its own, however. For stats, personally I'd go with the Gyroc Carbine, dropping the shots to 6(3i), the RoF to 1, and maybe making it Bulk -4. Damage would become 6d imp. Price would stay the same - the drop for a more simplistic design is countered by the need to handle finicky ammunition and the ability to broadcast the detonation signal. The spikes are probably heavier and would cost more than a micromissile; I'd eyeball them at WPS 0.2 and CPS $75 or so. The increased weight should drop their range; going to 1,000 is likely (not that that's likely to matter in a horror campaign). They still need space to get up to speed, as usual, so keep that in mind when the target is within 10 yards (which is likely to matter in a horror campaign). If you want better precision, you may be interested in picking up GURPS Vehicles, which has a nice chapter on designing weapons. It's a 3e product, so some of the stats will need converting, but damage, weight, and range are consistent between editions. You'll want to figure out MinST, Bulk, and Rcl based on similar weapons, and for 3e Acc is typically double 4e Acc.