[Spaceships] Missile shield vs. ramming: two questions
 

I'm trying to figure out how to build a space combat paradigm where large warships make logical sense, as opposed to being the result of mindless aping of naval warfare. Not that we don't want to ape naval warfare, we just want to do so in a thoughtful way. Here "large" = SM+9 at a minimum, or ideally SM+10 or higher.

The basic problem here is that cost scales with volume, while damage, armor, and HP scale with length. The main thing that large warships have going for them is that (1) they can potentially have enough DR to be immune to beam attacks from smaller ships (2) they can have beam weapons powerful enough to penetrate such armor on enemy craft. Unfortunately, this logic doesn't apply so much to kinetic attacks, because kinetic attacks can do incredible amounts of damage, especially when using the tactical combat rules where you aren't arbitrarily limited to a scale-based velocity.

The missile shield design switch from Spaceships 3 seems essential here, to stop large warships from being missile bait. But what about ramming? A couple things are unclear to me. First, if your RoF is higher than the number of ramming ships, do you get one hit per ramming ship, or one hit per point of RoF, which can be divided freely among attacking ships? I can't quite tell from the wording of the rule ("Beam weapons that are assigned to point defense may therefore automatically hit a number of incoming ballistic weapons (or ramming spacecraft) up to their maximum rate of fire.")

Second, would it be reasonable to use the "missile shield" rules not just for beams but also missiles? It seems like this could be extremely helpful, because (1) dedicated suicide drones can have very heavy frontal armor, enough to bypass point-defense guns designed for unarmored missiles and (2) by the standard rules, a point-defense gunner has a minimum 5% miss chance. Point (2) means an SM+10 warship (weighing in at 10,000 tons) can easily be destroyed by a swarm of a dozen or so SM+4 drones (10 tons each).

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Range.

You need a large objective to focus a beam at great distance, which in GURPS Spaceships means a powerful weapon, which requires a large ship. So build go with TL 10 or TL11 and build SM +12 warships with 100 GJ spinal UV or X-ray lasers. Fit each one out with a tertiary battery of thirty 1GJ very-rapid-fire UV lasers for RoF 3000 missile defence.

Then stand off at 100,000 miles and plink with the Big Gun. Any warhead or fire platform will cop hell while closing.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

One issue here is that VRF beams have 1/100ths of the output of regular beams, so those won't be 1GJ VRF beams, they'll be 10 MJ VRF beams. So those guns won't be very useful against a well-armored drone. Devote most of your front hull to hardened nanocomposite, and it will be difficult to impossible to so much as scratch the drone.

As for the big gun, that can be overwhelmed by sheer numbers. The big gun might have a range of 50,000 miles. With TL10 or TL11 drives they can easily travel at speeds in excess of 25 MPS. At that speed, the big ship will have less than one hundred 20-second turns to destroy incoming drones. So 100+ drones will overwhelm the big gun. They'll add up to a mere 1% of the tonnage of the monster ship.

Look at the Nightgaunt dogfight drone in Spaceships 4 to see now this is done in detail. If you tone down the armament, you can give them a fifth front armor system for extra protection against the little guns.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

You can use Particle Beams in the tertiary battery for that (5) armor divisor. Keep the UV Laser in the main battery for the range though.

If you're really worried about those drones add a tertiary battery of missiles too. They'll kill drones easily.

Mostly I agree with Agamemos. Range kills in normal space/hard science combat.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

For an SM+12 ship, even if you use the Smaller Systems rules, the missiles will still cost $1M a pop, almost as much as a Nightgaunt drone. You're better off using a fighter screen.

More importantly, though, you still have a 5% miss chance with each shot by RAW. Hence why I asked if it would be reasonable to get rid of that minimum miss chance as a house rule.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Can you give be a page reference on that, please? Acrobat Reader text search in my copy of Spaceships 8 doesn't show up "nightgaunt", "dogfight", or "drone".

So they will. My mistake. What about using a secondary battery of rapid-fire improved lasers? Ten weapons each RoF 20, 300 MJ? Improved lasers are penetrating (2), but AKVs probably have hardened armour. 3 d-dice × 5 should penetrate dDR 51, and damage an SM +6 AKV with five frontal systems of hardened nanocomposite. Range S/L, so you're getting effective damage out to 2,500 miles. A drone with 20 mps of delta=v is going to take at least 125 seconds to cross that, which is 6 20-second turns during which the defence gets 1,200 shots?

And if the thing that launches this salvo gets within 200,000 miles it can gloomily contemplate 100 GJ of x-rays: 2 d-dice × 50 burn* sur (5), after which the ship gets to used the big gun for 500 twenty-second turns of defensive fire against KKVs with 20 mi/sec of delta-v.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

It's on page 15...of Spaceships 4, not 8.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

I suggest that you read this rule in conjunction with "Spreading Fire" on SS1 p.58.

A gunner may choose to divide his shots
among different targets, either attacking multiple
targets, or firing at different parts of a single vessel.
All targets must be specified before rolling to
hit. It imposes an extra -2 penalty per different
target engaged (applied to all attack rolls) when
firing beams or guns, or a -1 penalty per target if
firing missiles. One attack roll is made for each
target.

So your gunner divides his RoF up among targets as he sees fit, and then each shot of group of shots fired at an "incoming ballistic weapon… (or ramming spacecraft)" is an automatic hit. "Automatic hit" as in "couldn't miss at any modifier" ought to mean that every round in the burst hit, because if you would have hit at, say, -10 and have Rcl 1 then you would have hit with ten rounds, right? It'd be foolish for an ease-of-use rules option to drastically reduce effectiveness.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Spaceships 4 is the one I didn't buy :(

Re: [Spaceships] Missile shield vs. ramming: two questions
 

It's an SM +4 bot with a spinal particle beam and 6g worth of high thrust water fusion torches. If you can extrapolate how SM +4 works, you can probably fill in the gaps yourself.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

I would say one hit per ROF divided up however you want. But roll damage after assigning targets.

Unless the incoming targets have ECM or are programed/guided to evade and they are far enough away I would say yes.
But there should probably be a minimum firing distance.
They key here though is t specifies beams, not guns as usable for the option. Presumably because the beams move so fast the missiles are effectively standing still. Point Defense missiles have terminal guidance so might be able to make up for that, especially if not dealing with ECM or evasive tactics.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

For the moderate-weight 'big ship' classes, RF is more suitable than VRF for anti-strike-craft duty.

VRF beams at 10 MJ are still good against (unarmored) missiles and shells, but 100 MJ is much more the thing for punching big ugly holes in small but somewhat hardened vessels. (Even there, against SM+5 or +6 with hardened armor a laser won't cut it.)

Re: [Spaceships] Missile shield vs. ramming: two questions
 

6 armour components on the front for a AKV. I guess that SM 4 hardened nanocomposite armour has dDR of 5 per system, so six of that is dDR 30. 2ddice × 5 ought to mess them up.

2 fusion torches on the rear gives 0.5 gee times 2 for high thrust times 3 for water which is 6.0 gee.

1 control room in the midships core.

11 tanks of water giving 15 divided by 2 for high-thrust divided by 3 for water = 2.5 mi/sec each. Total 27.5 mi/sec of delta-vee. Takes each one 7272 seconds to cross the range of a range X laser. Perhaps a better design for this purpose would be to dump the high-thrust and the water for 1 gee at six times the delta-vee, and take a run-up from outside range.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

You can't have 6 armor components on the front when you're armed with a spinal (or lesser fixed) weapon, only 5. The Nightgaunt only has 4, and the control room is in the front hull (core)...as usual for the worked designs in the Spaceships series there seem to be some dubious choices made.

You also left out power generation when filling in, there.

The 6G may make sense for a dogfight drone intended for heavy tactical maneuvering, as opposed to a relatively simple attack run. Whether that role is plausible in space is questionable, to be sure.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Indeed, but a KKV designed for ramming doesn't need a spinal (or lesser fixed) weapon.

Yes, but a KKV doesn't have any powered systems.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Sure, if you're building a big hardened missile rather than an AKV or drone.

Which you can do, but seems to come a little out of left field here.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Isn't that what Michael Thayne is fretting about? Isn't ramming the whole issue of the thread?



I can't discuss the Nightgaunt because I don't have Spaceships 4. I'll leave you to it.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Wouldn't it be possible for a force shield to be deployed so that a high velocity ramming vehical struck it at a 45° angle or better? It might also be possible for better than 5° angle. Explosive missiles would have unchanged effects as would beams but kinetic effects (such as plain vanilla hard to spot space junk when travelling at speed) would be defused more efficiently. To further tie it in to the OP a larger mass ship would have benefits in soaking up the kinetic energy.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

It is always good to remember that game rules are only an approximation and that people in the setting make decisions based on their reality not the rules. The 'machine gun vs. HMS Victory' problem is a classic example.

There is a post from David Pulver around 2008 talking about how he might scale HP to better represent the properties of large vehicles in WW II and the Falklands. I think that your thoughts about force screens are on the right track: settings with many big ships, such as Star Trek or the Schlockverse, usually have some kind of 'force field' technology, and that can allow big ships with big power plants to shrug off attacks.

(Similarly, I don't know whether Spaceships assumes the kinds of armour arrangements which specialists talk about- many thin spaced plates and things like that- or the intuitive 'great solid hard masses' which 90% of gamers will envision).

Re: [Spaceships] Missile shield vs. ramming: two questions
 

The OP didn't actually express a thought about force screens: the "Missile Shield" setting switch to which he referred is an optional rule regarding defensive fire by beam weapons against ballistic warheads and ramming ships. It's in GURPS Spaceships 3 on page 35.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Ok. I do not have money to buy any of the later volumes in Spaceships, and in my view for questions like this, it is always better to start with the real world ("on the back of an envelope, how would large spaceships work?") and worry about how to model it later.

Two common phenomena in naval architecture are big for the sake of big ("mine is bigger than yours!") and ships which have to serve multiple functions (the galleons of the Indes were treasure transports and armed to fight off filthy heretical pirates; an American aircraft carrier is a base for land operations and a weapon of naval warfare). Both can be reasons why there are ships bigger than a rational in-game analysis would justify, let alone our amateur analysis through the foggy mirror of the rules on a lazy Sunday.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

You asked two questions. I'm sorry that I was not more clear about which one I was answering where.

"Why build big ships?" you asked, and listed some points about armour ratings and beam weapon damage. You didn't mention range, but it can be significant. Big ships carry big objective mirrors and can therefore focus a weapon at ranges where a smaller ship cannot effectively return fire. In GURPS Spaceships that effect makes a tactical difference up to a 100 GJ UV laser or X-ray laser, for which you need an SM +12 ship with a spinal mount or SM +15 with a major battery. That's another reason to build ships larger than SM +9.

You also asked about defending such large ships against missiles and ramming. Though holding the launching ships beyond X range with the Big Gun is a start on that, you're right that the Big Gun can be swarmed. So I suggest a point defence with high rate of fire, and the use of the "Missile Shield" setting switch. Details remain to be worked out: perhaps a weapon system split into three SM +11 systems: one SM+11 tertiary battery of thirty VRF improved lasers (improved UV lasers at TL 11) for dealing 3D damage to each of 6,000 unarmoured warheads/turn out to S/L range, one SM +11 secondary battery of 10 RF UV lasers (improved at TL 11) dealing 2D×5 (2) to each of 100 (200 at TL 11) SM +4 or smaller fighters or KKVs per turn, out to L range, and a medium battery of three RF UV or x-ray lasers doing 6D×5 (2 or 5) to each of three cheeky pests per turn that have armour on them, out to range L, and useful fire against light targets trying to close from beyond-X to L. It's not immune to everything, but any swarm of warheads or KKVs launched from beyond the range of its Big Gun is going to have to run a hell of gauntlet, especially if you keep down to limited superscience in drive performance.

If attackers build KKV with massive plugs of hardened armour on their front sections, deploy large ships in pairs, or with escorts, that can pour rapid fire at the sides of closing KKVs.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Spaceships 8 (page 21) offers optical Phased Array lasers at TL11 and UV lasers at TL12. Only major batteries are available, and at TL11 they are only available as fixed mounts, but they can switch to rapid-fire or very-rapid-fire at will. They even function as LIDAR.

If you have TL12 (or TL 11 and play games with smaller-systems) you can equip an SM +12 ship with a phased array turret (or an SM +11 phased array in each hull section) that is a very versatile defensive weapon.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Also fits the "thoughtful aping of naval combat" mentioned in the OP. A chief advantage of 20th century big battleship guns wasn't just penetration versus armor or explosive power, but also greater range.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

First: Gurps HP rules are broken for large structures/vehicles. They are much harder to destroy than the cube root gives.

And related: In spaceships the beam weapon damage scales with cube root too to keep the damage scaling same as HP, but missiles and ramming do not.

The simple solution to that is: Use square root for both damage and object hitpoints. Square root is closer to real effect. This will both make beam weapons more effective against smaller targets and make larger targets tougher.

The damage square root is proposed in "The Square Root of Destruction" pyramid 3-34 page 9.

Second: Kinetic weapons are more effective due to the ability to get high speeds at higher TLs. This one is realistic but can be unsatisfying if you want large ships to survive.

The easiest solution to that is to use super science in the form of Force Screens that are silly good against kinetic threats. As example Vorsigan saga gives their Force Screens half normal dDR vs beams but fifty times normal dDR vs kinetics(so 100 times better than vs beams).

Alternative solutions include allowing smaller batteries on larger ships and not use rapid fire rules for massed batteries. Combining this with tactical combat where you have time to attack the incoming missile multiple times.

As example at TL 10, you cannot have more than DR 30 hardened as front armor and with The Square Root of Destruction a 30mj laser with 2d*10 will penetrate it easily. The battery weights 15 tons and needs 7.5 tons fusion power plant, so by using 2.25 times the drone mass(and remember that the attacker will likely use 1 2/3 times the mass to include the vehicle bays) you will get quite many shots at the drones(20+), with likely 2-3 hits needed to neutralize. So having say 1/4 the number of expected drones in defensive weapons should be enough. Under this system the automatic misses do not matter as you get so many attacks.

Alternative to beam weapon based defense is to use massed small missiles. Even a small missile will do devastating damage. Use massed Striker Missiles (UT 168) as a last ditch defense. No small target cannot have the armor to stop a 100mm High Explosive Multi-Purpose round with an effective dDR penetration of 126 against a hardened armor target(252 normal) and the missile weights only 17 lb and is a smart weapon so is independently targeting and make separate attack rolls. So launching 2 000(17 tons) to counter a 100 drone attack(1000 tons) is definitely feasible close defense. That gives 20 tries for each incoming drone by using a minimal part of the drone mass(1.7%).

Re: [Spaceships] Missile shield vs. ramming: two questions
 

We don't really have "the real world", though, so coming up with a plausible model and seeing what consequences it has can be helpful. And tabletop RPGs are arguably the best model we have–computer games have advantages for modeling space combat, but can suffer from AIs that use very, very stupid tactics.

"Big for the sake of big" only gets you so far, I think. If the rationally optimized warship size is SM+8, the biggest one or two superpowers might build some SM+10 ships, but even then the backbone of their fleet will still probably be SM+8.

Less sure about the multi-role thing. It would be interesting to stat out a multi-role ship under the Spaceships rules, where each role would only justify say a SM+8 ship. How big could such a ship get? Not sure it would get more than 10x larger than the "single role" ship.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

I think the issue is how range scales. A 30,000x increase in mass (and more importantly, cost!) only yields a 10x increase in range. So I'm not super-excited about this strategy. It's maybe compelling when you're designing something to assault space stations, which can't close range.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Your theories about this do not match up with my experience of Spaceships battles. My experience is that superior range wins hands down and quickly too.

The only time I have seen drone saturation work was against a space station that could not get out of the way v. a massive number of targets that had a closing velocity of 70 miles per second. This speed also allowed the vessels carrying the drones to stay out of range.

Hardening the drones played no role. If you're going to saturate the target's defenses adding missile launchers instead of armor is a much better deal.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

I'll think about this. One wrinkle: right now, kinetic damage for missiles and shells is weirdly based on cube root of mass, so if you did this really consistently you'd want to redo the "Conventional Warhead Damage Table" from Spaceships p. 68. Which isn't an argument against it, it might just take some extra work.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

If you use "HP and Weight: An Alternative Approach" from the same Pyramid issue as "The Square Root of Destruction", and round up generously in in canon Spaceships style, you might get an HP progression like this:

SM+4: 30 dHP
SM+5: 50 dHP
SM+6: 100 dHP
SM+7: 150 dHP
SM+8: 300 dHP

Still not sure about the warhead damage progression.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Somewhat, but didn't seem to consider that the attack drones could be entirely unarmed. You're right though that that's totally appropriate for the "dedicated suicide drones" mentioned in the OP.
Even if you have only moderately more range (never mind 10x more range) that's just fine if either your target cannot close that range fast (realistic rockets outside of a high-speed pass) or you don't need very many shots to resolve things (any moderate number of targets that aren't of similar size and massively armored).

But, to be fair, I do agree that the Big Gun strategy is likely to falter if you enable the Big Missile Swarm strategy, which leaves large ships facing off against thousands of KKVs and zero targets worth hitting with a 5000+ ton cannon.
Can you say what rules you used?

Because you probably remember all the analysis of point defense vs. massed missile fire back when Spaceships was new.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

The opposite of what the Op wanted but this is an interesting idea.
Build suicide drones that have their own missile launchers that they use once they get close enough.
The drones would be more vulnerable to getting hit at longer range by big guns but once they close they unleash a swarm to overwhelm point defense.

Overall though with the Missile Shield option turned on I think big ships are much more likely to survive but also escort ships that focus on point defense systems would be added.
With Super science drives a fighter screen also might be an option, though they would be wiped out quickly if used offensively.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Continuing the "square root-based damage thread", my proposed HP progression above gives an SM+10 ship 1000 dHP. That means 100 dHP of penetrating damage disables a system, 500 dHP of penetrating damage destroys a system, and 6000 dHP of penetrating damage auto-kills the ship.

One option is to leave kinetic damage as-is. On this approach, a 16cm missile traveling at 10 mps will average 840 points of damage—usually destroying a system, but not instantly vaporizing the ship the way it does under RAW. OTOH if you want damage from kinetic weapons to be more-or-less consistent with ramming damage, there's a case for significantly nerfing small warheads. Under the second approach, a 16cm missile might have a base damage of, say, 11d. at 10 mps, that's an average damage of 385. Now you're just disabling a system, not destroying it. Either way, this is probably an improvement.

I don't know what to do here partly because I think RAW missile damage is slightly too high to make logical sense–especially not for proximity burst, which should probably halve effective caliber. It does look like there's a germ of a solution to the "large ships are underpowered" problem here, though.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

In my scifi-setting spacehips and other large things are tough. Basically all large things use standard hitpoints, but have a raising injury tolerance(damage reduction).

To get he IT value look up the SM and use the corresponding speed as IT. So that a SM +7/300 ton scoutship is at IT (30) and SM +11/30 000 tons ship is IT(150).

(The scifi part is not the only one where I use that, I also apply it to large fantasy monsters in my current superheroic fantasy game)

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Personally I think IT:DR should be an optional system, though 1 level of it is already a freebie option for ships.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

This is fairly convergent with the occasionally-discussed option of adjusting wounding factors by the size of the target. Except that that would also factor in very big weapons, like nearly all Spaceships weapons, starting from a more favorable position than small arms.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

What ought range to go with, realistically? Naively (i.e. ignoring the engineering of pointing the things) the diameter of the objectives ought to go with [strikethrough]the square of[/strikethrough] ship length. And spot size can go with objective diameter where the weapon is constrained by beam intensity on the objective mirror. Which means that range ought to go with the 2/3 power of ship mass, divided by wavelength.

A factor of 30,000 in ship mass ought to deliver a factor of about 900 in range.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Er, do you mean objective area where you say diameter? Because it certainly doesn't seem logical that objective diameter should scale as the square of ship length, which would eventually lead to objectives bigger than the ship.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Yes. Sorry, I got tangled up while composing on a mobile device and without a pencil and paper. Objective diameter scales with ship length, not the square therefore. Effective damage range scales with the square of objective diameter, therefore with the 2/3 power of ship volume and mass.

But you get trouble with slew time, and lightspeed delay eventually reaches a point where targets' random evasion can take then entirely outside the beam path (depends on their diameter, unused acceleration, and ability to orient at random). That makes effective aiming distance an issue against an evading target.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Well, I used all of the Spaceship rules at different times.

I first went into missile salvos v. point defense during the playtest for Spaceships 1. This obviously became very important when the one shot kill quality of kinetic weapons at very high velocities became evident.

A general principle that one tertiary battery given over to point defense tended to cancel out one missile battery.

A bit of fluff text in the write-up for an "Ares" battlecruiser (I think it's in the Designer's Notes) about a possible weakness v. missile boats caught my eye. So I took the Ares and swapped out the main beam weapons for missile batteries and called the new ship type the Hydra..

The first thing I discovered was that the Ares had many light guns and was unable to penetrate its' own frontal armor and this made it an almost automatic loser against it's mirror image. So I made an Ares II that swapped a secondary battery for a larger one. That one showed little special vulnerability to missile barrages mostly because it could limit engagement length by damaging/killing its' opponent..

From this we develop the principle that a big gun is better than an equivalent mass of little guns except for missile defense. This fuelled my preference for main battery/spinal mount and tertiary battery with nothing in between.

You also see support for this in the damage rules where you want weapons heavy enough to actually disable the target hit location and not just damage it.

Then Spaceships 3 and 4 were tested together and it was with the mapped rules I did the space station attack. I used a Gibraltar station in defense and a Nova carrier with a bay full of TL8 ASATs.

The Novas stated out at Mars which is how they built up that 70 mile per second velocity. What I remember was that this came to 100 ASATs. There may have been multiple Novas to get that number.

Each ASAT could fire 3 missiles so the total number of incoming targets was 400 and this was too many to counter. Just one of the missiles gave you a _hard_ kill on the SM+14 asteroid station too.

A general result from multiple test battles is that they tend to be short in terms of number of turns. I attribute this to Spaceships realistic rules bias that mimics modern naval combat with its' "one shipkiller missile to one ship" tendencies.

Even older battles that appear longer and more epic only seem that way because we tend to count shots fired rather than those that hit and almost all shells fired miss. One shell from Bismarck sank the Hood. One shell from the Rodney effectively killed Bismarck.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

When I ask what rules you used, I mean how did you actually resolve this? Because there are definitely some differences in opinion on what the Spaceships rules are, and even more so how you should employ them. Are you rolling the entire missile battery as one attack, or rolling one attack per missile? You can do either by the book, if you've got enough gunners. What about the point defense battery?
Having read about WWI naval battles...no, those often involved legitimately substantial numbers of hits (and didn't necessarily kill the recipient ship either).

Abysmally low hit rates, sure. Sub-percentile at least some of the time. But many ships took solidly 2-digit hit counts in battles.

I'm pretty sure age of sail ships really could and did get hammered by a lot of hits, but I don't have statistics on that.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

On the other hand,three days earlier three shells hits from the Prince of Wales did not kill Bismarck. Neither did a torpedo hit from one of HMS Victorious' torpedo-bombers on the 25th.

In the final battle on the 27th, four British ships fired 2,800 shells at Bismarck and scored 400 hits. Then they sank it with two torpedo hits.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Attacks were rolled as a volley both for the attacking missiles and the defending PD. I believe this to be the norm for 4th ed and the author of Spaceships and the co-author of 4e did not correct my procedure(though he did catch other problems in my detailed reports). It appeared to be what was used by everyone else as well.

I just don't see this "roll every missile" imperative. It's more simulationist but 4e has gone against simulationism in ranged combat in general and Spaceships in particular is a fast and simple combat system.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

This is a good story. It's pretty much why I fret so much about missile defense.

Back on the possibility of using square-root based damage and HP to encourage large ships, after thinking about it more, I think the big challenge is armor. If you don't boost armor, you strip big ships of one of their original advantages. Not quite sure how to do it, though.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Apparently, King George V's 14 inch shells were largely ineffective against Bismarck's armor, so a lot of those hits were effectively meaningless. I've heard it claimed that the RN so wanted to be sure they killed it, they closed to point blank range. While that gave them a lot of hits, most of them were high, disabling things like gun direction and turrets (and most likely killing the bulk of the senior officers early on) but not having as great an effect on the seaworthiness as would ordinarily be expected.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

I'm not sure I'd call it an imperative, exactly...but it is permitted by the rules as written, if the attacker has the right features. And it increases performance immensely. (It's also actually an imperative per the text if your battery is turrets - the option to fire an entire battery as one attack is strictly for fixed batteries.)

While I don't know if I could respect it because I have little patience with the Rapid Fire rules being used in places where they're very non-simulationist, I do believe Spaceships might work better if it actually was written to enforce the spirit that you brought to the rules. But it's not written that way, and the way it is written either side of that missile/PD exchange gains a tremendous advantage by choosing to use their weapons otherwise.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

The first thing I can think of to offset the increase in beam weapon power under "the square root of destruction" is give an SM-based multiplier to DR. Something like this progression:

SM+4: x1.5
SM+5: x2
SM+6: x2.5
SM+7: x3
SM+8: x3.5
SM+9: x4
SM+10: x5
SM+11: x6
SM+12: x7
SM+13: x9
SM+14: x11
SM+15: x13

This is more or less consistent with how the Square Root of Destruction rules increase the damage output of major batteries. I'm a little worried that for some paradigms it might make ships too tough, but not sure what that paradigm is.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Proposed square-root based damage progression for conventional warheads:

2cm: 1d+2
2.5cm: 2d
3cm: 2d+2
3.5cm: 3d
4cm: 3d+2
5cm: 5d
6cm: 6d
7cm: 7d
8cm: 8d
10cm: 11d
12cm: 3dx5
14cm: 6dx3
16cm: 6dx4
20cm: 6dx6
24cm: 6dx8
28cm: 6dx11
32cm: 6dx16
40cm: 6dx22
48cm: 6dx28
56cm: 6dx32
64cm: 6dx44
80cm: 6dx60
96cm: 6dx80
112cm: 6dx100

Re: [Spaceships] Missile shield vs. ramming: two questions
 

I know there's a reason that Bismarck survived three shell hits from Rodney on the 24th, a torpedo hit and at least one shell hit on the 25th, and four hunred shell hits on the 27th, before being sunk by two torpedos, or whatever the hellish battering it took was. I'm just trying to give context to the statement that it was "effectively killed by one shell".

Re: [Spaceships] Missile shield vs. ramming: two questions
 

It probably worse better with general GURPS mechanics to use expanded wound size modifiers. I came up with mine here and several other people have had nearly identical schemes.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Note that Kromm said in pyramid #3-70 page 15 about Damage Reduction:
"Simple, and perhaps the one thing I most regret not imple-
menting in the Basic Set. It contains the seeds of solutions to
many problems (e.g., making it harder to destroy huge vehicles
and buildings using small arms)."

So using Damage Reduction to mane large things tough would seem to fit well with GURPS mechanics too.. :)

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Your point was clear and on-point to me. It also IMO is a godd example of how real ships don't largely get destroyed or not based on one "hit point" number that gets reduced predictably by every hit.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

By itself, it makes large objects too difficult to destroy.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

No, on the contrary, by itself it makes large objects still too easy to destroy. Firing a small arm at a planet should not even do that single point of damage.

Overall it is a question of how much Damage reduction should be gained at what breakpoints AND a basic change of the mechanics so that damage being below a certain % if the IT value being ignored.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

It means inadequate damage by large weapons.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

This is a slight tangent, but what about setting minimum sizes for various reactors or having size effect efficiency. That way smaller ships have to keep careful count of How much power they use while larger ships have power to spare.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Not really, even cruisers do not get destroyed by single hits(unless hit in a critical location) though the armor and in GURPS standard rules they would be destroyed so scaling it so that they do not would seem more correct.

Basically if you read any World War 2 combat account against things like cruisers and destroyers that are hit by larger ships main weapons, the hits clearly penetrate the armor and yet do not destroy the ship instantly in most cases.

As a random example because I happen to have watched a youtube video on the battle and then looked into it further: Battle of the River Plate in 1939. The heavy cruiser Exeter was hit seven times by Admiral Graf Spee and damaged severely but survived and was capable of returning to Port Stanley for emergency repairs.

In standard Gurps rules the 28cm shot would have easily penetrated the armor and thus a few hits would have caused enough hit point damage to destroy it at only 1024 HP or at least to make it dead in water.

There are plenty of other situations where the armor was clearly not enough to severely limit the damage and yet the ships took many hits by large guns and survived.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Anthony isn't suggesting standard GURPS rules as the alternative.

A 28 cm shell hitting the 575-ft Exeter is proportionate to a ~3mm round hitting a SM+0 target. Which would imply that an appropriate handling of scale would give at best a 1/5 wounding modifier for the hit (Exeter being unliving), potentially less.

Giving those shells the same effective wounding modifier as 20mm shells (which should be nearly harmless to such a vessel even ignoring armor) on the other hand is a bit harsh.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

I would not know, as the link he posted just goes to "script hell", the page in question wants to run 22 scripts at start and does not show any content without them, so it is unusable as a website.

But, yes giving a damage divisor of about 1/5th would likely be in the right ballpark for realistic figures. (I use a LOT higher numbers on my games but that is for cinematic effect of large spaceships/structures requiring massive damage over time to reduce to rubble)

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Heh. It's actually relatively modest by the standards of script hell, though I might move it to something more vanilla. However, commenting on something you didn't read seems... odd. The basic idea is that weapons have a SM and wound modifiers are based on relative SM, so a pi+7 weapon on a SM+5 target acts as pi++, on a SM +7 it acts as pi, on a SM+9 target it acts as pi-, larger targets get larger divisors.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

I did not comment on the contents, only offered an alternative way to do it as proposed by Kromm.

You are the one who started to comment on that proposal.. :)

Re: [Spaceships] Missile shield vs. ramming: two questions
 

It loads without difficulty on my browser, as it turns out, though I'm finding it incredibly unclearly written. I believe that it would rate the 28 cm shell as pi+7, then subtract off 12 for the SM of Exeter and 2 more for Unliving to 'pi-7' for 1/15 wounding factor. (Not clear to me what effect the shells' follow-up explosion would have.)

I hadn't clicked the link until now. Anthony's in-post description was more than sufficient to inform what I had posted previously.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Checking if I understand your proposal right: if a ship fires a major battery at a ship 1 SM smaller than it, the attack has a x1.5 wounding multiplier. 2 SM smaller, a x2 multiplier. 1 SM larger, a x2/3 multiplier. Etc.? Is that just for beam weapons, or does it cover kinetics? I *think* you mean kinetics to have a wounding multiplier based on caliber, but I'm not quite sure I follow how to calculate it. Also not sure I follow how ramming would be affected.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

A worked example could really help clarify the expanded wounding modifiers proposal. Writing up how it could affect the bajillion ASATs vs. Gibraltar scenario could be helpful (with the ASATs both firing missiles and trying to ram).

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Interfacing it with Spaceships takes a little more work than just using it - you need to decide what the final caliber of the kinetic weapons is (you could just use the face values, but in theory probably shouldn't), and how beam spot size varies with weapon size.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

The way it's written seems to imply you don't need beam spot sizes, that you can simply go by SM of an equivalent Major Battery. Not sure I 100% understand the details, though.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

The problem with missiles is mostly that they don't scale the same way as beams, for reasons that are not entirely obvious. In general 7-10mm should be considered SM+0 for projectiles.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Is there a good reason not to use the face values? I know the Spaceships bullets/missiles are complicated, multi-stage affairs, but is there any reason in a vacuum to have them start out wider than the payload? The only one I can think of would be if you want to make them not as long, but I'm not certain a wider-but-shorter missile is any easier to store/load, and the fact this makes the missile an easier target while it's en route seems like it would negate any potential benefit.

Of course, the projectiles from proximity detonation should have smaller WM... but then they should presumably also do less damage*. Anyhow, +4 corresponds to roughly RoF 20, and 1/20th the mass is typically going to mean a bit over 1/3rd the diameter (assuming the fragments are around the same shape as the original warhead), so between -3 and -2 to SM (and thus WM) would be appropriate.

*As GURPS typically has collision damage scale as the cube root of mass, assuming something between 4 and 5 fragments per "hit," and between 80 and 100 actual fragments, you actually get the equal damage and +4 to hit you see in Spaceships. Of course, at that point the armor divisor should be something like 0.5 (if the fragments maintain the AP quality of the original warhead) or 0.25 (if the fragments don't maintain the AP quality, or if up against Hardened armor)...

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Oh okay, yeah. That's rolling in some kind of assumption about what those sizes are, at least implicitly, but is easy to implement.

It means that an SM+4 drone shooting a spinal beam at a SM+10 frigate would have a wounding scale of +5-10 = -5, resulting in 1/7 wounding modifier to make any damage they manage to drill through armor that much more disappointing. Meanwhile a major battery on the frigate would hit the drone with a scale of +6 for x6 (suggested) or x10 (pure log scaling) wounding, which is largely gratuitous considering it's got 30 dice of base damage. But a tertiary RF weapon on the frigate, being 10MJ, would only rate as SM+5, giving it a +1 factor against the drone for a WM of 1.5x.

From the bit about the sizes of holes made by projectiles, we can conclude that if one of the SM+4 drones rams it should have a wounding scale of its SM+4 + 13 = +17. That hitting the SM +10 frigate would do x7 or x15 wounding, which is...again largely gratuitous considering how much base damage it'll be bringing.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Because the warhead may not be the part of the rocket that's setting the lower bound on cross section. Long and narrow isn't a bad profile for a kinetic-kill warhead, but small diameter isn't great for rockets and fuel tanks.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Is 11-15mm then SM+1? And <does some extrapolating> the 16cm missiles from Spaceships are SM+7? Does that mean the wounding multiplier is x1/3?

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Well, that's for piercing damage. I don't recall what damage type missiles in Spaceships are.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Strangely, kinetic attacks in Spaceships don't seem to have any damage type listed. I guess I would treat it as crushing, since crushing is the type that normally has no special effects.

ETA: In this thread it was previously noted that this is unclear, but also that pi++ and cr both have a x1 wounding multiplier vs. unliving.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Well, pi++ is 15-20mm in that scheme, so 16 cm winds up as a 1/7.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

It's probably worth looking into the physics of damage, because at collison speeds above a mile per second most warheads are going to act like explosives or shaped charges, not like penetrators. They'll punch a small, slightly over-calibre hole in the face of the armour (or in the first layer of standoff armour (Whipple plating) and then spread out as they go in.

As for beams, producing widers spots for more damage is not a strategy that I've heard discussed. Rather, talk always seems to be of producing the minimum possible spot size to get the highest beam intensity and most violent interactions possible (drilling, explsive spalling) withou having beam intensities on the objective mirror that cause damamge there. I guess that once you reach a spot intensity high enough to achieve the most desireable effects you could increase spot size in line with objective size. I'm just not sure that that's fruitful if the mechanism of damage is to induce explosive evaporation of the target.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

It's not really a strategy, it's a somewhat unwanted side effect (there tends to be a limit on practical aspect ratio for drilled holes). Also, the way Spaceships scales beam damage (cube root of beam energy) means it must be generating wider holes at higher beam energies.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Ahah, I forgot to factor in Unliving, which is a flat -2 to piercing type, right? 16cm = pi+8, so that's -2 from relative size with an additional -2 from Unliving, so effectively pi-4? I think I understand the system now.

Would an SM+4 ramming ship–if you treated it as a piercing attack–have a relative size of pi+6 vs. an SM+10 ship? Reasoning: size of a projectile is WM-12, so reversing that, WM is SM plus 12. So the absolute WM of an SM+4 drone is pi+16, and the relative size is pi+6?

EDIT: For the ramming drone, I guess that would be pi+4 once you factored in Unliving.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Just so. Beam spreading is an unwanted side effect, not a fast route to increased damage.

Right, so be careful about applying a "hole width" multiplier to a base damage that already reflects hole width.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Damage types other than piercing do not have hole width modifiers, and should. At the same penetration, a wider hole is certainly more destructive.

Re: [Spaceships] Missile shield vs. ramming: two questions
 

Testing my understanding of this system by applying it to the ASATs vs. Gibraltar scenario:

At a relative velocity of 80 mps, the 16cm missiles inflict 6dx320 damage, largely trivializing the Gibraltar's 45 dDR. But, the Gibraltar gets a x1/30 wounding multiplier, so the missiles only inflict an average of 224 points of damage. That's enough to disable a system, but not destroy the Gibraltar in one hit. Rolling damage for each hit individually, you'd need 12-13 hits on average. And with the "Multiple Hits" rule from Anthony's article, you'd need 30+ hits from one salvo.

Did I do that right?