Missiles are fun, and even more fun when you don’t roll badly on the cluster table. That’s why Artemis IV FCS is always a good idea to install on every launcher, right? Well… maybe not. But Artemis IV isn’t the only FCS, just the most prevalent. We’re also going to talk about Streak, Apollo MRM FCS, and a secret bonus thing! So what, mechanically, is the benefit of the Artemis and Apollos systems and when is the best time to use them?

In science, there are a pair of concepts used to describe how effective you are at achieving your target: accuracy and precision. Accuracy is how effective you are at hitting the target; precision is how close your attempts are to each other. In BattleTech, accuracy is your attack roll and precision is the result on the cluster table. You still need to actually hit with the attack roll before the cluster table comes into play.

Artemis IV FCS adds +2 on the cluster table, Streak effectively adds +10, and Apollo removes a +1 to hit at the cost of -1 to the cluster table. Some of these are easier to evaluate than others, but the place to start is the cluster table itself.

FCS usage is a game of probabilities, and when debating the inclusion of an FCS really you’re looking at how you can improve your average damage per turn. With this in mind, the question becomes whether it’s cheaper to use the FCS or to add more launchers (and all the infrastructure those require).

Artemis IV is the big one, and the most prevalent option since it can apply to SRMs, LRMs, and MMLs. Adding Artemis IV to a launcher costs 1 ton, takes up 1 slot, and costs no additional heat. This, or similar, is going to be a theme when it comes to FCS systems. So what you want to know above all is how much damage an Artemis system adds for that ton. Luckily, I’ve already done the math! When looking at this table, don’t forget to multiply the average Cluster Table roll result by the missile’s damage (1 for LRMs, 2 for SRMs).

Should you add Artemis to a launcher? If it’s an SRM launcher or an LRM 5, probably not. Artemis is at its finest when it’s supporting the larger LRM launchers. Still, if you’re dedicating launchers to a ‘Mech design and you want the best results out of them, what are the options?

Streak is just really good. What’s the average difference in damage between an SRM 6 and a Streak SRM 6? An extra 50% damage, which comes at the cost of 1.5 tons and no extra slots. On top of that, Streak tech means your ammo lasts longer since missed shots won’t fire. By comparison, Artemis adds 19.5% damage to an SRM 6 and lacks any of the other benefits (plus it takes up space).

But let’s say Streak tech is off the table. If you’re only mounting 1 or 2 SRM 6s and you have the tonnage to spare, it could be worth it if there’s nothing more pressing the design requires. But here’s the thing: if you have 3x SRM 6s, it costs 3 tons and 3 slots to add Artemis IV for a 19.5% damage boost. Meanwhile, it costs 3 tons and 2 slots to add another SRM 6 launcher to do, on average, 33% more damage. If you can’t afford the extra 4 heat or can’t budget with the design’s existing ammunition, then this is a case for Artemis. But it gets harder and harder to make that case for any launcher sizes below 6.

For SRMs? Streak is best. If not Streak, then bigger launchers (6s are better than 4s are better than 2s). If not bigger, then more launchers. If more won’t fit, then Artemis. There is a slight exception to this rules because SRM 2 are just really good for their tonnage, so sometimes if you’re optimizing for tonnage, SRM 2s are better. But that’s real edge case stuff.

Launcher sizes of 7 and up are where things get good for Artemis and for FCS systems as a whole. Artemis is just a blanket good decision in this category, especially because MML 7s are where SRM ammo exceeds the break-even point for all missile types (it’s more rewarding to put Artemis IV on an MML 7 than it is to mount more MML 7s). There’s not even really much nuance for me to dig into here. Do you have LRM 10 or bigger? If yes, Artemis good. So really the question becomes is Artemis IV better or worse than going up to the next size of launcher?

Going from an LRM 10 to an LRM 15 gives you an average increase of 3.19 damage (approx. +50%) for the cost of 1 heat, 2 tons, and 1 crit slot. Artemis IV costs no heat and half the tonnage for an extra 1.36 damage (approx. +21.6%). So when correcting for tonnage (comparing the increase per ton of equipment), the LRM 15 wins here by a narrow lead (0.235 damage). But in a build where you’re tight on tonnage or need to save heat? LRM 10 + Artemis IV is a competent alternative to an LRM 15.

Going from an LRM 15 to an LRM 20 is a different matter, though. An LRM 20 does 33.6% more average damage than an LRM 15, but an LRM 15 gains 21.1% damage from mounting an Artemis IV. An LRM 20 means an increase of 1 heat, 3 tons, and 2 slots. Pay 3 tons for 33.6% damage or 1 ton for 21.1%? LRM 15 with Artemis is a clear winner here.

For MMLs? If it’s a 7 or 9, Artemis IV is at least as good as more launchers. For LRMs? As we’ve seen, it’s a little complicated. The take-away more than anything is that if an LRM 10 or 15 fits on your build with Artemis IV, it’s probably a good idea. If you need to save on weight or heat, consider replacing LRM 20s with LRM 15s with Artemis IV.

There can be only one. If I’ve ever talked to you about BattleTech, you know what’s going to be here: it’s the Archer ARC-5CS. ComStar are bastards, and they knew exactly what they were doing. I don’t bring the 5CS to friendly games unless people are okay with cheese, because that ‘Mech feels like cheating and this is why.

Why are MRMs like this. Apollo has its own separate section specifically so I can talk about how to estimate average damage as it to-hit bonuses relate to it.

I like to assume 7s as an average to-hit number for all weapons, so really I should multiply all the damage values I use by 58.33% (the probability of rolling at least 7 on 2d6). But no one wants to think about Medium Lasers as doing 2.9165 damage. It’s annoying. So instead, I assume damage values as they exist have already done this (5 = 2.9165) and do math to compare from there.

What does that mean? A weapon hits 58.33% of the time and we accept that it deals 5 damage. On average, it’s doing 58.33% of 5 but we’re ignoring that. A weapon with a -1 to-hit modifier hits 72.22% of the time (the odds of rolling 6 or better on 2d6). 72.22/58.33 is 124%. This is the math I use to estimate a -1 to-hit as being +24% damage. Below is a quick-and-dirty bit of my spreadsheeting that expands on that:

I wonder if all this math will come up later in some super secret bonus section, or if this was all just for the benefit of everyone’s least favorite missile launcher…

So, looking at this, MRMs start at a disadvantage: they start off with a -29% damage debuff. Which sucks. Apollo removes that debuff. That’s good! But it applies a -1 to the Cluster Table… how bad is that, exactly? Surprise, it’s not too rough. And certainly not so bad in exchange for the accuracy increase:

Figuring out the effect on MRM launchers means using these modified cluster table results and then comparing those numbers to the results of the less accurate unmodified MRM launchers. It was very annoying work to do, but you’re welcome to it if you’d like to verify my numbers. The end result is something you may have guessed: MRM 10s are no fun, but just like with LRMs? The bigger the launcher, the bigger the reward. Putting Apollo on any MRM launcher (except the MRM 10) provides a huge boost, well in excess of what you would get from just adding more launchers. Not only that, but the amount of damage that single ton of FCS buys you is unparalleled in the range bracket MRMs operate in. Only things that come close are the RAC/5 or the Rocket Launcher 15 (which is notably single-shot).

For an example, the Templar TLR1-OH mounts a pair of MRM 30s with Apollo FCS. Why the TLR1-OH? Because I like Templars. And… it’s… it’s fine. Little hot. The Akuma AKU-2X is probably a better ‘Mech, but I’ve not played with either of these myself yet.

That’s everything, right? We talked about accuracy and precision, about how Artemis buffs precision and Apollo buffs both… so what’s left? Probes and Actuator Enhancement Systems (AES). But those aren’t FCS! You’re right, but they do both buff average damage which means that they’re competitors for that same tonnage.

For anyone unfamiliar with AES, it’s an advanced rules level tech available starting in 3070 that grants a -1 to-hit modifier to all weapons mounted in the same arm as it. And that does mean all, including physical attacks and missiles. AES weight and size scale with the ‘Mech’s tonnage, so really it’s best when used on Light and Medium ‘Mechs. If you look back a couple tables, you’ll see I’ve included a graph that says a -1 to-hit modifier is roughly equal to a 24% damage increase. This is why I’ve made a point to describe Artemis and Apollo in terms of % damage buffs.

On Light ‘Mechs, an AES system costs the same 1 ton and 1 slot as an Artemis system but applies to all weapons in the arm instead of only to the paired weapon. So right away you should be seeing the huge boon this offers. Plus, math-wise, an AES system is better for an SRM 6 than adding Artemis even if you’re only mounting one SRM 6. Going up to Medium ‘Mechs, the system does get a little more expensive: 1.5 tons / 2 slots up to 50 tonners, 2 tons / 2 slots at 55 tonners. In Heavy ‘Mechs, the restricting factor becomes slots more than it does tonnage: 2 tons / 3 slots on 60 to 70 tonners, 2.5 tons / 3 slots at 75 tons. Still, if you can mount at least two launchers in that arm, the AES will outperform Artemis IV on all launcher sizes. And, since it gives the benefit of Apollo without the cost, it also outperforms Apollo FCS for MRM launchers (though probably at a premium since launchers that big are going on big ‘Mechs).

So what does any of this have to do with Active Probes? Probes have an optional rule that let you ignore 1pt of Target Number modifier generated by woods, jungle, or smoke if the target is within the Active Probe’s range. The Bloodhound Active Probe has a range of 8, compared to the max range on SRMs of 9, which means that if you mount a Bloodhound, and you’re good with maneuvering, you can shoot through some foliage as if it’s not there. The Bloodhound Active Probe takes up 2 tons and 3 slots, but applies to every weapon on the ‘Mech. It’s not quite the same as getting an active to-hit bonus like AES, but it is a way of preserving your SRM’s average damage while giving yourself a little extra protection.

Turns out the best FCS is actually just always hitting. Who knew! But now you know the costs and benefits of Artemis, Apollo, and AES for when you go to design your own ‘Mechs.

Bloodhound Active Probe will return in…
The Defense Onion