Question about homing weapon lock on

[z0boson]

Hallo!

I am a bit confused about the way homing weapons are used, in particular about the lock on action.

So Basic p. 413 says that to lock on you need to make an aim maneuver followed by a weapon skill roll. What modifiers do I need to apply to the lock on roll? For example, if the target has IR cloaking, is there a modifier to lock on with an IR seeking weapon or only on the attack roll of the projectile?

If I do not lock on (failed roll or not enough time), can I still fire the weapon? From p. 413 I get the impression that I can fire the projectile anyway, but it does not get the Acc bonus to its attack roll.

If I fail the lock on roll, can I try again next round?

Thanks in advance for your help!

[Ulzgoroth]

Originally Posted by z0boson

So Basic p. 413 says that to lock on you need to make an aim maneuver followed by a weapon skill roll. What modifiers do I need to apply to the lock on roll? For example, if the target has IR cloaking, is there a modifier to lock on with an IR seeking weapon or only on the attack roll of the projectile?

It just says a roll against Artillery (Guided Missile). It doesn't state any modifiers at all. So to my read that means only generic modifiers (like 'doing two things at once' penalties or environmental conditions) and anything specified in the skill description (BS178-179).

...Unfortunately the skill description's modifiers section includes "All relevant combat modifiers;". Whatever that's supposed to mean. I'd probably have to disregard that clause as devoid of information, but I wouldn't be happy about doing it.

I don't see anything indicating that target stealth should penalize the lock-on roll. If general modifiers for seeing the target did apply, that would pretty much cripple the entire guided weapon mechanic since those modifiers include range.

EDIT: I'd interpret it as an equipment operation roll rather than a 'do stuff to target' roll, but I can't really claim that the rules say so.

[z0boson]

Originally Posted by Ulzgoroth

EDIT: I'd interpret it as an equipment operation roll rather than a 'do stuff to target' roll, but I can't really claim that the rules say so.

Interesting, I haven't thought of it this way. Intuitively, I would have thought of it more like a sensor operation roll (It seems somehow logic that the launcher's sensors need to see the target to achieve lock on). But maybe the idea of this roll is only to make sure that you operate the weapon correctly and to give some usefulness to the Artillery (Guided Missile) skill.

[Ulzgoroth]

Originally Posted by z0boson

Interesting, I haven't thought of it this way. Intuitively, I would have thought of it more like a sensor operation roll (It seems somehow logic that the launcher's sensors need to see the target to achieve lock on). But maybe the idea of this roll is only to make sure that you operate the weapon correctly and to give some usefulness to the Artillery (Guided Missile) skill.

And prevent people from operating smart weapons at default with no trouble!

It does seem logical that there would be a sensor-based requirement for lock-on...on the other hand if there was homing weapons with imaging senses (which take regular range modifiers) would be nearly impossible to use against distant targets, which would rather defeat the purpose. Unless there were huge bonuses to that roll, which don't appear to be documented anywhere.

[z0boson]

Originally Posted by Ulzgoroth

And prevent people from operating smart weapons at default with no trouble!

Well, the warheads in UT have 13+ attack rolls, so they are going to be quite useful even without the Acc bonus of the weapon skill roll. However, the Basic rules state that the skill of a homing weapon is 10, which seems to contradict the descriptions in UT...

[Ulzgoroth]

Originally Posted by z0boson

Well, the warheads in UT have 13+ attack rolls, so they are going to be quite useful even without the Acc bonus of the weapon skill roll. However, the Basic rules state that the skill of a homing weapon is 10, which seems to contradict the descriptions in UT...

Well, sort of two things to consider there.

One is that UT is just a bit of a clunky book, so it might be doing it wrong.

The other is that specific supersedes general.


It might be intended. UT also has brilliant munitions that can probably take directions in natural language, after all. Modern smart weapons require a certain amount of understanding to use, I think (Artillery is an IQ skill, remember), but future ones might not so much.

[acrosome]

Originally Posted by Ulzgoroth

I don't see anything indicating that target stealth should penalize the lock-on roll.

That... really doesn't make any sense. If the target has stealth vs the kind of sensor that the weapon uses to track it then it's stealth definitely should penalize the lock-on roll. That's the whole point of jet exhaust cooling systems, for instance- to make it harder to lock an IR sensor onto them.

The rules even say "e.g. radar ignores darkness but can be jammed..." This implies that locking on is sensor-specific and appropriate stealth/camouflage/whatever penalties apply. I guess I'd just propose that if you're using the weapon's sensor to make the like- like with a Sidewinder or other IR homing missile- then you suffer any penalties for lock on appropriate to that sensor. And under modifiers it says "Base visibility modifiers on the projectiles homing sense...anything that jams this sense... gives a penalty to hit." So you should get a double-whammy: penalty to lock on AND penalty to hit. In practice, though, this will just mean that it take slinger to lock on since you can just try again next turn. Which seems realistic.

Note: the rules for guided weapons say to ignore range modifiers, though not size or speed modifiers.

[Ulzgoroth]

Originally Posted by acrosome

That... really doesn't make any sense. If the target has stealth vs the kind of sensor that the weapon uses to track it then it's stealth definitely should penalize the lock-on roll. That's the whole point of jet exhaust cooling systems, for instance- to make it harder to lock an IR sensor onto them.

The rules even say "e.g. radar ignores darkness but can be jammed..." This implies that locking on is sensor-specific and appropriate stealth/camouflage/whatever penalties apply.

And under modifiers it says "Base visibility modifiers on the projectiles homing sense...anything that jams this sense... gives a penalty to hit."

Note: the rules for guided weapons say to ignore range modifiers, though not size or speed modifiers.

What I bolded above is the key thing you seem to be overlooking the significance of. Various modifiers, including stealth-related ones, apply to the roll to hit. But the roll to lock on is completely different from that.

[z0boson]

Originally Posted by Ulzgoroth

What I bolded above is the key thing you seem to be overlooking the significance of. Various modifiers, including stealth-related ones, apply to the roll to hit. But the roll to lock on is completely different from that.

I guess the main problem is that the rules never state what you are actually doing with this "lock on". Are you just pointing the weapon in the right direction to give the missile a head-start (then why is it IQ-based?). Are you checking the target (then why don't you use visibility modifiers?). Are you just making sure that you are correctly using the weapon (then why don't you need to roll when changing magazines on normal weapons?).

[z0boson]

Originally Posted by Ulzgoroth

One is that UT is just a bit of a clunky book, so it might be doing it wrong.

Indeed, High-Tech homing missiles have no value for skill (so I guess they use the basics rules of 10) and large Acc, while UT missiles have high skills and low Acc (3, lower than high-tech launchers). The HT way seems more consistent, but maybe it was done by purpose to make the UT rounds more autonomous.