I've posited elsewhere that the CT High Guard ('80) nuclear missile is a 12-ton yield surface-impact mini-nuke. That's consistent with its effect in that game and with the penetration if it were a Striker weapon facing a ship under those rules. It's not consistent with the HG '80 black globe rules, if you adopt the convention that the EP described represents a full turn's output from whatever weapon is hitting it - and it's hard not to adopt that convention given that the energy absorbed can then be used for jump. If you go there, you end up with a 12 kiloton warhead: those can pretty well vaporize 40% of a Scout/Courier, which is not what happens in that rule set.
Then I thought: "Hey, let's vaporize the scout!" So I did up some very rough guidelines on the use of larger nukes in High Guard.
(We acknowledge that the rule set has some basic limitations that make extrapolation tricky, so one extrapolates with caution and a good degree of unreliability, but it can nonetheless be rewarding sometimes.)
If we assume a standard missile is 12 ton yield, gaining a -6 bonus to the damage roll, then:
This is based off the Striker armor table, which does this curve thing that, past a certain point, ends up very roughly increasing the armor factor by about 8 for each doubling of thickness, and MT's armor-to-bonus calculation, which is a bit easier to work and makes more sense than what Striker offers for translating to space combat armor levels. For example, whether you assume a space combat armor level of 1 is an Striker armor rating of 60 or an MT armor rating of 43, increasing armor (or penetration) by a factor of 10 increases armor rating (or penetration) by 26, which ends up being roughly a +9 to the space combat armor level (or a -9 to the damage roll if it's weapon power being increased). Since the nuke blasts in all directions rather than focusing, I figured the increased penetration as a cube root of the increase in power.
This will in some cases throw rolls off the top of the chart: most or all possible results are a critical when the larger nukes encounter more lightly armored ships. When fiddling with beam weapons, I'd adopted the rule that after all bonuses and penalties including armor are added, the net result can't be less than 0 - basically an unmodified roll - because I figured at some point it's punching through the ship and sending most of the energy out the other side into space. However, for nukes, it seems appropriate for a critical result to occur more often (or all the time) because that unfocused blast is cratering large chunks of a ship like a humongous set of jaws rather than punching through like a lance. So, the bridge disappears in a cloud of incandescent plasma, or the boat bay becomes a glowing crater, or a big bite is taken out of the engine room, and so forth.
As for where to put these warheads, the 12-ton yield warhead seems to be modeled on a real-world warhead, the W54, a nuke designed to be intentionally inefficient to reduce its blast to something an artillery piece could fire without killing the crew. That warhead actually managed 6 Kt in the Hardtack II Socorro full yield test, so I'd boost the turret-launched missile to 5 kt at no added cost if I want nuclear missiles in the game with some real bite.
-8 on the damage roll, and 40% of the scout is indeed getting vaporized - well, 30% - with a missile no bigger than the one already in the game.
Striker thinks the bay-launched missiles are 25 cm and, although MT doesn't agree, the missile bay is flexible enough that one can argue for provisions to launch larger missiles from it. Cost becomes a consideration - bigger warheads cost more - though there is no real consistency on what they actually cost. Cost might be three times as much as the turret missile. Modern era warheads as small as 117-125 kg have delivered 170-200kt (W-58, W62, W-69), so most likely a 100 kt missile would mass around three times the mass and volume of a 5kt turret missile, which makes the bay a good candidate for 100 kt missiles.
Warheads in the megaton range run to 250-300 kg (W56, W59) and would need missiles of more than a half ton or so in mass and a liter in volume if you just scaled up; a single battery-round for a factor-9 battery comes in over 2 dTons. You'd need to give room for ammo storage and keep track of how many you have and how many you'd used, but they'd be deadly, with enough of a punch to completely neutralize Factor-15 armor and give a chance at a crit against even that level of armor. They'd likely cost about ten times as much as the turret missile. At 45 MCr per factor-9 battery-round, with 5 of 6 battery-rounds being stopped by dampers and more stopped by repulsors and such, you're spending a lot to get the hit, but the target's going to really feel that hit. Destroyers will in fact be destroying each other rather than engaging in slap-fights, and SDBs would be a fierce opponent for capital ships (assuming they're no more than a tech level or two below their target).
https://en.wikipedia.org/wiki/Nuclear_weapon_yield
A bit of a hodgepodge mix-and-mash, but it seems to work.
Another interesting idea is to develop a neutron warhead. The warhead would be designed to detonate at a stand-off range to reduce the blast effect on the hull but to deliver an enhanced radiation blast: give it a -5 on the radiation table and no surface damage bonus. The idea would be to eliminate critical and interior results while killing crew and damaging the computers. The weapon would be intended to quickly disable an unarmored target without causing too much damage, giving a warship a better chance to quickly seize a freighter as prize and put a prize crew aboard to make away with it, rather than spending several turns trying to cut down the maneuver drive and weapons enough to allow an opposed boarding. Seems like the kind of thing the Vargr would appreciate.
Then I thought: "Hey, let's vaporize the scout!" So I did up some very rough guidelines on the use of larger nukes in High Guard.
(We acknowledge that the rule set has some basic limitations that make extrapolation tricky, so one extrapolates with caution and a good degree of unreliability, but it can nonetheless be rewarding sometimes.)
If we assume a standard missile is 12 ton yield, gaining a -6 bonus to the damage roll, then:
- a 0.1 kt (100 ton) yield warhead gains a -9 bonus (-3 net after the +6 penalty for batteries of Factor 9 or less).
- a 1 kt yield warhead gains a -12 bonus (-6 net after the +6 penalty for batteries of Factor 9 or less).
- a 5 kt yield warhead gains a -14 bonus (-8 net after the +6 penalty for batteries of Factor 9 or less).
- a 10 kt yield warhead gains a -15 bonus (-9 net after the +6 penalty for batteries of Factor 9 or less).
- a 100 kt yield warhead gains a -18 bonus (-12 net after the +6 penalty for batteries of Factor 9 or less).
- a 1 Mt yield warhead gains a -21 bonus (-15 net after the +6 penalty for batteries of Factor 9 or less).
This is based off the Striker armor table, which does this curve thing that, past a certain point, ends up very roughly increasing the armor factor by about 8 for each doubling of thickness, and MT's armor-to-bonus calculation, which is a bit easier to work and makes more sense than what Striker offers for translating to space combat armor levels. For example, whether you assume a space combat armor level of 1 is an Striker armor rating of 60 or an MT armor rating of 43, increasing armor (or penetration) by a factor of 10 increases armor rating (or penetration) by 26, which ends up being roughly a +9 to the space combat armor level (or a -9 to the damage roll if it's weapon power being increased). Since the nuke blasts in all directions rather than focusing, I figured the increased penetration as a cube root of the increase in power.
This will in some cases throw rolls off the top of the chart: most or all possible results are a critical when the larger nukes encounter more lightly armored ships. When fiddling with beam weapons, I'd adopted the rule that after all bonuses and penalties including armor are added, the net result can't be less than 0 - basically an unmodified roll - because I figured at some point it's punching through the ship and sending most of the energy out the other side into space. However, for nukes, it seems appropriate for a critical result to occur more often (or all the time) because that unfocused blast is cratering large chunks of a ship like a humongous set of jaws rather than punching through like a lance. So, the bridge disappears in a cloud of incandescent plasma, or the boat bay becomes a glowing crater, or a big bite is taken out of the engine room, and so forth.
As for where to put these warheads, the 12-ton yield warhead seems to be modeled on a real-world warhead, the W54, a nuke designed to be intentionally inefficient to reduce its blast to something an artillery piece could fire without killing the crew. That warhead actually managed 6 Kt in the Hardtack II Socorro full yield test, so I'd boost the turret-launched missile to 5 kt at no added cost if I want nuclear missiles in the game with some real bite.
-8 on the damage roll, and 40% of the scout is indeed getting vaporized - well, 30% - with a missile no bigger than the one already in the game.
Striker thinks the bay-launched missiles are 25 cm and, although MT doesn't agree, the missile bay is flexible enough that one can argue for provisions to launch larger missiles from it. Cost becomes a consideration - bigger warheads cost more - though there is no real consistency on what they actually cost. Cost might be three times as much as the turret missile. Modern era warheads as small as 117-125 kg have delivered 170-200kt (W-58, W62, W-69), so most likely a 100 kt missile would mass around three times the mass and volume of a 5kt turret missile, which makes the bay a good candidate for 100 kt missiles.
Warheads in the megaton range run to 250-300 kg (W56, W59) and would need missiles of more than a half ton or so in mass and a liter in volume if you just scaled up; a single battery-round for a factor-9 battery comes in over 2 dTons. You'd need to give room for ammo storage and keep track of how many you have and how many you'd used, but they'd be deadly, with enough of a punch to completely neutralize Factor-15 armor and give a chance at a crit against even that level of armor. They'd likely cost about ten times as much as the turret missile. At 45 MCr per factor-9 battery-round, with 5 of 6 battery-rounds being stopped by dampers and more stopped by repulsors and such, you're spending a lot to get the hit, but the target's going to really feel that hit. Destroyers will in fact be destroying each other rather than engaging in slap-fights, and SDBs would be a fierce opponent for capital ships (assuming they're no more than a tech level or two below their target).
https://en.wikipedia.org/wiki/Nuclear_weapon_yield
A bit of a hodgepodge mix-and-mash, but it seems to work.
Another interesting idea is to develop a neutron warhead. The warhead would be designed to detonate at a stand-off range to reduce the blast effect on the hull but to deliver an enhanced radiation blast: give it a -5 on the radiation table and no surface damage bonus. The idea would be to eliminate critical and interior results while killing crew and damaging the computers. The weapon would be intended to quickly disable an unarmored target without causing too much damage, giving a warship a better chance to quickly seize a freighter as prize and put a prize crew aboard to make away with it, rather than spending several turns trying to cut down the maneuver drive and weapons enough to allow an opposed boarding. Seems like the kind of thing the Vargr would appreciate.