NEBULOUS: Fleet Command Comprehensive Craft Clobbering Compendium for Chic and Comely Captains: A guide on ACM design and usage

Interlude I: The New Missile Bodies

2 new Missile bodies were added with the carrier update: the SDM-1XX ‘Lunge’ and the SDM-2XX ‘Typhoon’. Both of these are 2-stage missiles with a very fast, higher range first stage, and a slower, more maneuverable second stage.

The SDM-1 has an S1 for its second stage, where the SDM-2’s second stage is a shorter range, slower and slightly more agile S2 with a smaller warhead.

These missiles are also locked to one specific warhead: the SDM-1 to blast-frag EL, the SDM-2 to blast frag, and thus cannot be used for anti-ship work.

The staging on SDMs works like hybrids: seekers which measure distance will give themselves an extra fuel margin to stage, seekers that do not will have the missile stage immediately on detection. Additionally, SDMs will stage when their 1st stage runs out of fuel, unlike hybrids

Getting Out There (Range, Intercept Time And NEZ)

The NEZ, or No-Escape-Zone, is the distance at which the craft cannot escape the missile, even if it immediately runs away from the missile as fast as it can the second the missile is launched.

This is obviously affected by the missile’s max range, but its speed is also a very important factor.

Say we have two missiles with a 8km max range, one going 200m/s and another going 500m/s fired at a craft that goes 100m/s.

The former missile reaches its max range in 40s, the latter in 16s, in this time the craft can move 4000m and 1600m respectively, meaning the NEZ for these respective missiles (max range - max distance the craft can travel) comes out to 4000m and 6400m respectively.

By default, Craft NEZ is respected by the PD controller, this can be turned off as the last setting in the PDMSL doctrine, and is always ignored when a craft is designated a priority pd target.

How much time it will take for your missiles to intercept the target is also a factor, if you’re trying to intercept a flight of craft heading at you to strike you, you ideally want your ACMs to hit them before they can release munitions, which a faster ACM (all else being equal) will of course be better at.

These two aren’t strictly required though, you can still hit craft even outside the NEZ, provided they don’t make enough of an effort to run out of range (which is not particularly common).

Intercepting pre-launch is also not entirely needed, it might need some time to launch its entire payload.

Additionally, CMD missiles will also lose guidance if the launching craft is killed, this is of course still worse than killing them while they’re still attached to the carrying craft, but it might still save you.

Note that incoming missiles also force craft to engage in defensive maneuvers, which may stop them from getting close to you as quickly.

ACMs mounted on craft of course have less issues with range, given they are on a rather fast craft that can get out there to intercept, though especially for air superiority, range can matter a fair bit, standoff munitions can let you punch into larger flights or ones with better guns (provided they do not have munitions with that much range) as well as forcing the enemy flight evasive first, allowing you to close in for guns or use cheaper wake missiles.

Note that ACMs will give themselves a rather generous fuel margin to hit when fired from craft.

If you are using arm launchers with off-angle on, you will also want to look at the maneuverability of your missiles, as arm launchers force hot launch on, meaning your missiles may need to turn to face the target while flying out at speed, adding cold gas to your ACM can also work wonders here (can also be useful for VLS).

Keeping Track (Seekers)

In order to hit craft, your missiles have to keep track of them with their seekers, a more complex task than with AMMs because craft get universal access to countermeasures, unlike missiles where bringing decoy support modules is a very significant choice.

These craft-launched decoys have both a radar as well as a wake signature on the same object, meaning they will seduce any combination of ACT and WAKE (even ACT/[WAKE] which ship-launched countermeasures cannot seduce).

However, this does not mean either of these seekers are bad, in fact WAKE can be surprisingly resistant to countermeasures: even if it does go for a decoy, it will often reacquire on a nearby craft after flying through the cloud of chaff and flares.

Wake also tends to go for rear-aspect hits which are favorable, as we will get into in a future chapter.

Note that WAKE does not give distance information however, something very important for some SDMs.

ACT is also no slouch, given it gives range and velocity information for optimum tracking, as well as having no aspect requirement like wake does, however SGM-2 and SDM-2 tend to have issues with the craft leaving the seeker basket and thus missing entirely, so ACT without a WAKE backup to get it back on track is a rather poor choice on these bodies.

Of course this would not be a defensive missile guide without going over CMD; a seeker that remains the premium option due to perfect target discrimination, working from any aspect as well as being able to track targets no matter which way the missile is facing.

Its high cost does however mean that you probably want to be equipping only more individually capable missiles with this seeker, Track Quality is also a much more significant consideration, as craft tend to be intercepted further out than missiles, meaning your Track Quality may well be worse.

Common seeker combos are:

S1: WAKE (only used in dogfights), ACT

SDM-1: ACT, CMD

S2: WAKE/ACT, WAKE/CMD, CMD

SDM-2: ACT/WAKE, WAKE/ACT, CMD/WAKE, CMD

Keep in mind that missiles without cmd seekers do not get midcourse guidance and are thus simply launched at a predicted intercept point assuming the craft keeps its current velocity (something that often is not the case)

Slower missiles thus need to be careful about seeker selection if you want to use them at longer ranges without missing, however this is only really an issue with ship launched S2 or S2H.

Chase And Hit (Hitting Craft)

Unlike missiles, which conveniently make an active effort to get to your ship as fast as possible, craft tend to prefer self-preservation and will actively try to evade incoming missiles.

This means that, unlike AMMs, your missiles will actually have to chase and close range on craft, instead of simply putting yourself between the incoming missile and the ship you are protecting.

This means ACMs make tradeoffs between all 3 engine stats:

Burn time to keep chasing the craft for longer and maybe even come back around for multiple tries at hitting.

Speed to close with craft in less time, thus letting what burn time you have do (at times significantly more work).

And of course agility so your missile can actually turn to hit the target.

Finding a balance of these requires tuning and testing your missiles (or simply stealing existing ones for dissection or use), and there aren’t too many hard and fast rules.

However, trending towards medium speed and high agility tends to produce the best results.

Note that sometimes, slightly lower agility can be beneficial, as it causes the missile to lag the target, resulting in more likely rear-on hits

S1s and SDM-1s tend to be the most forgiving, S2s require some more work to perfection, while SDM-2s are a nightmare with more or less 1 specific tuning that really works well.

SDMs, as two-stage missiles can also split the jobs of getting close and then turning in to hit between their two stages somewhat, you’ll need less speed to chase when your booster dumps you out relatively close to the target.

SDM-2s especially can make use of this to great effect, as increasing their warhead isn’t very expensive, unlike SDM-1 where you have to pay for EL (the S1 at the end of them also gets plenty of base speed).

Reducing the staging range on the main stage through various means including maxing out the warhead counterintuitively lets you increase the overall performance of your missile, as being dropped off very close to the target craft lets you put more resources into maneuver and make less of a tradeoff by dropping speed and main stage range.

Further information on this will be in the “Minstage SDM” Design showcase at the end of the guide.

Fighters, Skiffs and Pikes will also attempt to shoot down incoming missiles of a size larger than 1 (so anything not an S1 or SDM-1) with their nose guns, gunpods andany applicable frag missiles they have.

Getting around this is mostly a matter of volume, though the high speed boost stage on the SDM-2 also allows it to be somewhat resistant to fighter guns and AMMs if it stages only at close range, terminals and penaids can be added, but are very expensive and may decrease your chance to hit.

Here it’s mainly an exercise in avoiding use of S2s against fighters, as these will be targeted and rather reliably shot down, as well as the age-old truth of firing more missiles getting you a better chance at landing hits.

Lethal Effect (Warheads And Hit Angle)

The premier Warhead options for ACMs are frag warheads, basic frag is an option on all missiles (except the SDM-1 which is locked to EL), with EL being a premium option for S1s which lets you 1-shot instead of 2-shot fighters, albeit at a price point where you might consider just bringing an SDM-1 instead.

The hit-chance mechanics for frag warheads work like they do against missiles, with 2 significant changes.

Firstly, both frag warheads get a flat percentage point increase to their hit chance against craft at all aspects, this scales (roughly linearly, exact curve unknown at this time) with the size of craft, with the maximum of 40% applying to bombers, skiffs and the sundial at size 1.0, with lower bonuses to fighters at threat size 0.75 and the pike at size 0.6.

Secondly, Bombers will take 50% of the listed damage even when the frag missile fails the roll to hit.

(Note that All missiles are size 0.0, so not affected by this mechanic)

If you are at all familiar with AMMs, you will know that warhead size breakpoints are very important here, this too is the case with ACMs, though there is a second factor to consider with these.

Namely, all craft (except the pike which gets 0.1cm) get 0.3cm of skin thickness (remember, skin thickness got divided by 10 with this update, so this would be equivalent to 3cm pre-carriers), which means that even if you hit enough damage to 1-shot a craft, you might not actually be able to, as insufficient armor pen means you will only deal half the listed damage.

This is mainly an issue for blast frag, as it’s armor pen is notably lower than EL (this allows EL S1s to 1-shot whereas regular frag ones cannot), on the SDM-2 you’ll also want to pay attention to the armor breakpoint especially, as that’s the main decider of your lethality, while also important for S2s, these usually run max warhead as this means you can 1-shot bombers, which nets you more than enough armor pen even with base frag.

However, HP breakpoints are still important to keep in mind, craft HP are as follows

Pike: 40

Tanto: 50

Barracuda: 60

Skiff: 130

Bombers, Sundial: 135

The biggest to watch out for here is that your S1s will want to be tuned differently between the factions for anti-fighter work, as getting 60 damage to 1 or 2-shot Barracudas with an S1 needs max warhead, whereas OSP can get away with a warhead one pip smaller.

The other big consideration is Bomber HP, which you’ll need a max warhead S2 to reach, only the S2 and bigger can achieve this.

For those in mood for some excessive violence, you can also get twice a bomber’s HP in damage on containers, meaning you can guarantee a kill on any you catch in the blast radius.

HEI and HEKP warheads will damage craft on a direct hit, but direct hits with any kind of missile body, tuning and seeker are not reliably achievable, and while HEI or HEKP ACMs (which will guaranteed 1-shot of they do hit) can work, don’t expect great results from them.

Note that with the carrier update all missile seekers gain an inherent inaccuracy (aside from cmd which works off of the always imperfect track information), which is what makes direct hits unlikely for all seekers.

Interlude II: Notes On ACM Usage

Comprehensive Craft Clobbering Compendium for Chic and Comely Captains: A guide on ACM design and usage image 74

ACMs on ships will only fire automatically if PDZONE is on AREA, manual PD prio works the same as it does on missiles.

Don’t worry too much about multiple AMM/ACM types on the same ships, ships will always prefer to fire defensive missiles set to target the thing you are prioritizing manually.

Firing at craft outside of the NEZ (the maximum range where craft cannot run away from the missile so it runs out of range) is a choice to be considered, especially for ship-launched S2s (and to an extent S1s) which have a very small NEZ, and thus you may want to chose to launch further out, at the risk of being run out of range.

The NEZ is respected by default for automatic launches (can be changed in the AMM posture settings) and will always be ignored for manual PD prio.

For the purposes of pd threat size, pikes and skiffs count as size 1, fighters count as size 2 and bombers and the sundial count as size 3.

The Following Table gives an overview of how the different bodies generally perform against different craft types:

Green means they are going to be generally effective

Yellow means there are limitations (e.g. range, lack of damage)

Orange means you should only be firing these in a pinch (S2H are very expensive and do not get good pK against anything that is evading)

Red means they will flat out not work (The Skiff is extremely good at defending itself with 35mm turrets).

Note that craft will pay attention to what seeker their ACMs are using, WAKE missiles for example will only be fired if the craft have rear aspect on their target.

Non-CMD ACMs, especially those of larger sizes, tend to become significantly more effective when you space them out a bit more, else they will all tend to focus on just one target and sail off ignoring the rest of the flight, or possibly even kill each other.

Spacing them out too far against especially lone targets though tends to have the second missile hook on craft countermeasures and not acquire the target.

The spacing out of ACM launches through various means has been dubbed “Osu” by the community, owing to one having to order launches in a specific rhythm .

The ideal spacing for SDMs is pretty tight, around half a second or so, maybe even faster at the start, beyond 1s performance starts to degrade significantly.

For VLS or MLS you give manual PD prio or fire orders in the rhythm (note the 1s defensive refire time on vls-2).

For craft best results are doing things analogously with fire orders, with your formation on FOCUS, then right click to give repeat fire orders on different craft, one click = 1 missile fired.

on AUTO instead of focus, if you can’t manage the micro of turning to FOCUS and back again after, you’ll fire a couple missiles per click which is slightly worse, but can be useful in some cases for extra saturation.

Firing a couple more SDMs than incoming enemy craft is fine, they do not have 100% pK (probability of kill) after all, however having craft fire ACMs on UNLIM Salvos may be rather wasteful.

Design Showcase

This Section goes over a handful of specific ACM designs, selected for proving effective in practice or being particularly notable.

Each section also includes a little note from the creator of the missile.

Minstage SDM

The minstage SDM is set up to stage as close to the target as possible, this allows it to spend less main stage engine tuning to chase, as well as generally staging in a way that it will hit craft in the rear, allowing for better chances to get an intercept, as well as better chances to damage when an intercept occurs.

The high speed of the boost stage being active until very close also gives these pretty good resistance against craft-launched AMMs and craft guns.

The minstage SDM has a (near) max-speed boost stage (at maximum burn time for the speed), and a max agility main stage for a speed of 175-180m/s, in order to reduce the stage range enough, you need to max out the warhead size.

The tuning on these is very specific, with significant performance loss with only slight changes to the main stage, SDM-2s that do not minimize the staging range also perform rather badly, so this tuning is more or less the only good one.

These work with act/wake and cmd (optional backup or cold gas bottle) seekers.

Note these do not work well on off-angle arm launchers, as these force hot launch and the boost stage does not have the space to get extra maneuver.

This missile was designed by Mathblob with help from Natasha.

Creator’s note: “We made the missile worse as a joke”

Vren’s Breadstick

The Breadstick is a max warhead Blast Frag (not EL) S2 primarily designed to kill bombers, as these can 1-shot those. The Wake primary means the missile can chase craft and get rear on hits, making it more softkill resistant, more lethal when it gets an intercept and, coupled with a long range (as all the fuel for the S2 is in one stage) it can come around for two or more tries more often than not.

The large blast radius also lets it catch multiple craft at once on occasion.

The Breadsticks’ main downside is its vulnerability to being shot down by fighters as well as its small NEZ, meaning more often than not you’ll want to fire outside of it, making you potentially vulnerable to being baited out.

Both WAKE/ACT, WAKE/CMD and CMD with a cold gas bottle (lets the missile get out really fast) work, though use a cmd-based one on ships for midcourse guidance, craft can get closer in, so no midcourse is less of an issue for them.

The Breadstick uses a max warhead at 227m/s and 4g turning, tunings around this area are going to be generally effective.

The Breadstick was designed by Vren.

He recommends bringing at least 1 TALS or 2 SALS to fire these.

Creator’s note: “Also I wasn’t going to call it ‘the Vrenstick’ Sorry rye bread”

Max warhead BF S1s

This is just a max warhead blast frag S1 with an act seeker, nothing fancy, really short range due to anti-missile performance wanting near or max maneuver, but they work great in a pinch when stuff does get close.

You’ll usually see these as incidental emergencies on cappers.

Firing these on Salvo Size 3, MAX DOF with NEZ on lets you get the best value out of these, though you will need to set PD to AREA to automatically fire on craft in range, manual pd prio works too if you can micro it (though this does ignore NEZ).

There’s no one that really made this missile, as it’s an existing one that got repurposed, but Das is probably the most enthusiastic adopter.

Creator’s note: “Enough of these on a shuttle and you can stop God”

Anti-Bomber Containers

The CM-4 is the only missile that can guarantee 1-shots on bombers due to the 50% damage on a failed roll they take.

ACM containers were made many other times by many other people, but Wzsnipes “perfected” and used them a fair few times.

These have a 9 pip warhead with 149 m/s speed and 3.6 g turning, netting you around 4.5 km range, these boxes use CMD/ACT seekers.

Using these is rather finicky and not super reliable, you’ll absolutely need these on manual launch, with a spacing of 2-3 seconds between launches to avoid the containers killing each other.

When you use them against torpedoes (which you can also do), first target torpedoes closer to the rear of your ship for liners, as they'll hot launch towards the front of your LN, after that, fire them at further forward/further ranged torps.

Creator’s note: “its got like 20% live game success rate”

Hybrid ACMs

Against most craft, hybrids are a rather poor choice, given not only their high cost, but also their high speed making them generally hit evading craft in the side, netting you bad hit chances.

There is however an exception in the skiff, whose 35mm guns, especially when loaded with flechette, are extremely good at killing anything short of extremely high agility terminal S2s and terminal hybrids heading for it.

Given skiffs will generally have a gun on their nose (and all the ones worth killing with missiles won’t have a second), they tend to conveniently present their front aspect to any missile fired at them, partially negating the tendency of hybrids to hit the sides of craft (the needed terminals do give you some back).

S2H with a max size frag warhead can 1-shot a skiff, so these are generally preferred, give these weave or else they will not hit, and make sure the cruise stage has good maneuver (a bit over 2g turning), you’ll need it to get to the ~1km staging range a max size warhead affords you while under 35mm fire.

For the sprint stage, you’ll want a bit more maneuver over base (a bit over 17g) to avoid being shot down, though not too much else the weave path tends to make them hit the side of the skiff more.

Acknowledgements

I would like to thank:

Natasha, Vren, Xenophon and Rye Bread for proofreading the guide.

Vren, Wzsnipes, Natasha and Das for their input.

Rye Bread for help piecing together the name for this guide.

Toastymedic for help with filming the Showcase videos.

Source: https://steamcommunity.com/sharedfiles/filedetails/?id=3402874173

Comprehensive Craft Clobbering Compendium for Chic and Comely Captains: A guide on ACM design and usage