Missiles: Guided or “unguided”?

[Akamia]

I’ve heard from a variety of folks that apparently missiles such as LRMs and SRMs are unguided somehow. This flies in the face of not only anything I know about missiles in general, but what I’m reading on Sarna about both missiles in BattleTech.

Typically, an “unguided missile” is just a rocket, and that exists in BattleTech already, separately from any of the extant missile systems. So how can LRMs or SRMs be unguided? I’ve heard of “semi-guided” munitions, but I suspect that, for the regular munitions, that doesn’t mean what some people think it means…

[Adrian Gideon]

We’ve got to accept there are a lot—a lot—of electronics, EW, ECM, and so on at work in BattleTech universe that is essentially background noise and taken for granted, such that it has no bearing on play and rarely mentioned in the lore. When specific equipment or rules (C³, Artemis, ECM suites, etc.) are called out, those are pieces of equipment that work above and beyond standard existing systems.

That doesn’t precisely answer your question—intentionally—but it should give you an idea on how to look at it and why these discussions come up.

[Akamia]

Yeah, I’m aware of all that “background noise”; that, if I recall, is the official explanation for all the effective ranges of weapons being so short, going back as early as Decision at Thunder Rift, possibly even earlier. To my knowledge, that hasn’t changed since.

But I’m looking at the rules and I’m not buying that there’s no guidance at all in standard LRMs or SRMs, even with all that noise. I asked this on r/TheNagelring last night, and a number of folks pointed out that most LRMs and SRMs are at least semi-guided – one clarified that they’d be more precisely described as semi-active radar homing missiles. The ones that aren’t are specifically referred to as dead-fire missiles. The missile behavior – specifically LRM behavior – is apparently most accurately portrayed in MechWarrior 5: Mercenaries, wherein the missiles home in on the locked target until the lock is broken. The lock can be acquired directly, or indirectly with a spotter; if the lock breaks at any point before the missiles land, they (probably) miss.