LOS for a walker

[gwensdad]

This has recently come up and our group was in a debate as to what counted as line of sight for a walker (dread in particular). One person has it that a walker can only see within the 45degrees of it's weapons while most of the rest of us believe it has the regular infantryman's 360. Is there anyplace where this is spelled out (stupid question, I know but rules lawyers are rules lawyers)

[DarkLink]

The walker itself can SEE 360 degrees. This was resolved with regards to Chaos Dreadnoughts (some people thought that they could only see units within the weapon fire arc, meaning the Dread wouldn't turn around and shoot the closest unit). I belive GW FAQ'd this.

Now, the walker can only FIRE within the 45 degree arc. This is done due to armor facing issues. So a dreadnought can't shoot a unit, then pivot to prevent another unit from hitting it in the rear armor.

[zed]

I thought it was 180 degrees to the front. Pretty sure we've been playing that for a while

[SeattleDV8]

The 180 was a 4th (or was it 3rd) Ed rule.
Walkers have a 45 degree LOS, but in the shooting phase it is allowed to pivot on the spot so( as long as it is not immobilised) it has a 360 degree LOS.

[Aldramelech]

The 180 was a 4th (or was it 3rd) Ed rule.
Walkers have a 45 degree LOS, but in the shooting phase it is allowed to pivot on the spot so( as long as it is not immobilised) it has a 360 degree LOS.

Agreed.

[gwensdad]

The walker itself can SEE 360 degrees. This was resolved with regards to Chaos Dreadnoughts (some people thought that they could only see units within the weapon fire arc, meaning the Dread wouldn't turn around and shoot the closest unit). I belive GW FAQ'd this.

Now, the walker can only FIRE within the 45 degree arc. This is done due to armor facing issues. So a dreadnought can't shoot a unit, then pivot to prevent another unit from hitting it in the rear armor.

any chance I can get the source of this, since (without saying too much) it does involve a chaos dreadnought?

[Exitus Acta Probat]

I am quoting myself from a different forum here, but it's easier than re-writing/hashing everything..so if it seems out of place (12" ref or what have you) that is due to a specific question response.

"actually, 12" refers directly to LOS, and LOS is VERY specifically handled by vehicle rules differently than it is by infantry units.
LOS from a vehicle is drawn from weapon mounts(BRB pg 58/59), at a 45 degree arc from each mount. You COULD very easily argue that an infiltrating unit could ignore the north bound end of a south bound Leman Russ if the turret was facing same. We don't think in those terms, because it is very rare for vehicles to be in a situation without ground support/other units nearby...(not and live for long anyway).

Walkers provide a conundrum, in that they operate like a mix of infantry and vehicles. The key here is this, and that is the fire frenzy rule actually overrides the steps found on pg 72 BRB. The basic walker rules state that you pivot during the movement phase, pick your target, then shoot (paraphrase).
The rules in the chaos codex state "at the beginning of the shooting phase it must pivot on the spot towards the closest VISIBLE(emph mine) unit..." (pg 40 CSM),
not "pivot the walker on the spot so that its guns are aimed at the target (assume that all weapons mounted on a walker can swivel 45 deg like hull mounted weapons) and then measure the range from the wepaon itself and line of sight (emph mine) from the mounting point of the weapon and along it's barrel as normal for vehicles." (pg 72 BRB)

note that on page 16 BRB (1st paragraph second column) "Line of sight represents your warriors' view of the enemy- they must be able to see their foe though." Now we assume, falsely, that all units have visibility independent of LOS, but here we see that is not the case. It is just a comfortable place because we've grown accustomed to using infantry as a primary locus. Not anymore, with MECH prevalence, we really need to re-evaluate how we 'SEE' things on the battlefield.

Fire Frenzy specifically overrides the basic shooting steps, and forces you to choose a visible target PRIOR to pivoting on the spot and nuking the shasta outta it. Visibility for a vehicle, as we have now determined, is a result of LOS determined from it's weapon mounts. It really is going BS crazy, and this could easily have a detrimental effect as well. Jump a death co behind one to run up in your grill, and watch what happens when it fire frenzies against that 5 man combat squad in front of it just barely in range...that''ll be one PISSED OFF chaos player."

[DarkLink]

If it is regarding Chaos Dreadnoughts, then I think these links will help.

http://www.belloflostsouls.net/2009/03/goatboys-40k-thoughts-how-i-plan-my.html

http://www.belloflostsouls.net/2009/03/goatboys-40k-thoughts-dont-get-ruled.html

The first raises the issue that you're probably encountering, the second resolves it.

[gwensdad]

Those 2 articles were exactly what happened. I only wish Goatboy had a link to GW that "proved" dreadnoughts could see 360. The person we're having the problem with was arguing against even seeing 180 degrees in front.

[DarkLink]

Heck, it'd be kinda nice to get more common FAQ updates. I mean, GW doesn't really deserve most of the bad rep a lot of players give it with regards to rules development and supplementary support, but I can't imagine it take that much time to throw a FAQ together.

[SeattleDV8]

I The key here is this, and that is the fire frenzy rule actually overrides the steps found on pg 72 BRB. The basic walker rules state that you pivot during the movement phase, pick your target, then shoot (paraphrase).


That is incorrect. Although the walker can pivot in it's movement phase it is also allowed to pivot in the shooting phase to pick a target. It is not stuck with the facing it had at the end of movement.

[Nabterayl]

I think the conceptual trouble here is that some players get it into their head that you can only shoot at what you can see, which isn't true. You can only fire a weapon at things you can see. Strictly speaking, you shoot first, then check LOS, and then fire. You're allowed to check LOS at other times, of course, but you are absolutely allowed to declare a shooting attack against units you can't see. It will, of course, miss - but if you didn't check to see whether your unit had LOS before you declare the attack, too bad.

I find that thinking about it this way helps to clarify issues like this. The vehicle has 360-degree LOS, just like all other models in 40K, because there is no rule specifying what a model's arc of sight is.* However, vehicles are different from most models in that the LOS check as part of the shooting sequence is from individual weapons. So it may be, for instance, that a Land Raider can see a unit, and yet not be able to shoot it because none of its weapons can. This is why Fire Frenzy permits the Chaos dread to pivot toward the nearest target it can see, and then attack. Otherwise, either there would be no need to pivot (because anything the walker could see it could also shoot without pivoting).

[Exitus Acta Probat]

The rules with regards to vehicles is pretty clear, and it is that LOS determines what can be seen, and LOS is drawn from the Vehicle weapon mounts.
We handle (reflexively) walkers as infantry, because we are trained (by prior editions/the BRB to a certain extent/convention) to do so, when in reality we need to be a little more careful how we handle them.
The Chaos Codex presents a 'paradox' in that it specifically tells us to follow a sequence that sounds NEARLY identical to the BRB, and yet in one bit of order change (that we have no choice about) it conflicts with the basic rules.
It may have been poorly thought out. But, reading the vehicle rules again and again, and the Chaos Dread rules again and again, you cannot escape that visible, to a vehicle, is defined by it's weapon mounts...and that subtle change in the wording on the CSM Dread makes so much more sense than it did when it first came out. TLOS was in the works when the CSM dex was printed. This may be a simple case of pre-planning, as was a number of other things we didn't understand the importance of until after the 5th ed rules came out.

[Nabterayl]

The rules with regards to vehicles is pretty clear, and it is that LOS determines what can be seen, and LOS is drawn from the Vehicle weapon mounts.
We handle (reflexively) walkers as infantry, because we are trained (by prior editions/the BRB to a certain extent/convention) to do so, when in reality we need to be a little more careful how we handle them.
The Chaos Codex presents a 'paradox' in that it specifically tells us to follow a sequence that sounds NEARLY identical to the BRB, and yet in one bit of order change (that we have no choice about) it conflicts with the basic rules.

The trouble I have with this argument is that it makes part of the CSM codex invalid, not only at the time of writing (under 4th edition) but at present, as well.

Let's assume that you're right, and a vehicle can only see what its weapons can see. As all of a Chaos dread's weapons are hull-mounted, they have a 45-degree arc of fire. Assuming you're right, that means the Chaos dread has a 45-degree arc of sight.

The CSM codex tells us, if we roll a Fire Frenzy, to pivot the walker toward the closest visible unit. Because the dread's arc of sight is exactly the same as its arc of fire (assuming you're right), there will never be a situation where the walker has to pivot. If a vehicle's arc of sight is co-extensive with its arc of fire, the closest visible target will always be in the arc of fire, with no pivoting necessary. This is true both if the walker's weapons have a 45-degree arc of fire (5th edition) or if they have a 180-degree arc of fire (4th edition).

However, I don't think that you are right. Let me try to rephrase my argument, which is just a repeat of the conclusions reached in the articles linked to earlier:

Page 72 of the rulebook tells us, "When firing a walker's weapons, pivot the walker on the spot so that its guns are aimed at the target ... and then measure the range from the weapon itself and line of sight from the mounting point of the weapon and along its barrel."

However, page 16 tells us, "If no models have line of sight then a different target must be chosen."

From the above, it follows that a walker must be able to choose a target even if its weapons have no line of sight to the target. From this fact, one of the two must follow:
Page 72's pivoting rules override the page 16 general rules about choosing a target.
Walkers have a 360-degree line of sight, even if their weapons do not.
Nothing on page 72 says that 1 is true. The wording implies that it is not - we are told to choose a target, "and then" check LOS from the weapon mounts. Since 1 does not follow, 2 must.

[Exitus Acta Probat]

Simple breakdown, I'm not going to quote all pages and such as we all know where they are at this stage.

Step 1, determine LOS. As infantry has it's own caveat specifically stating 'don't worry about it' we don't need to reference this except as part of the step.
We then go to the vehicle section, which states that vehicles (excepting turrets) only draw LOS from the weapon mounts at a 45 degree angle. Upon determining LOS, you then determine range from the weapons that actually CAN engage.
With Walkers, we get the same caveat in their own sectionl, as we do for infantry...you choose a target, then pivot...determine LOS and then range, and then shoot.

The CSM codex actually spells a VERY specific sequence of events that differ dramatically...though at first glance it does not seem to.
it says, upon rolling fire frenzy, to determine LOS first...THEN pivot...then shoot.
As this is an uncontrolled response by the vehicle, and not the player, we don't have a choice to pivot first...we have to determine LOS first, then pivot toward the target, then engage. the 'dex gives us no choice here, and actually spells out those steps.
Following LOS for vehicles, and the steps mapped out to us under fire frenzy in the CSM dex, we are stuck with this procedure.

I am not arguing this from my own original thought processes either, I had to be convinced by someone else from a different source, and be shown quite specifically WHY it worked the way it did.
I really understand the recalcitrance, and the innate reaction of 'he77s to the no!', but it really works...
:)

[Nabterayl]

Simple breakdown, I'm not going to quote all pages and such as we all know where they are at this stage.

Step 1, determine LOS. As infantry has it's own caveat specifically stating 'don't worry about it' we don't need to reference this except as part of the step.
EDIT: Are you referring to page 11? I don't think I buy that as an infantry-specific caveat. Treating it as a LOS caveat implies that, e.g., jump infantry do have a facing.

[Exitus Acta Probat]

N:
sorry, yeah. I'm talking about page 11. :)
I got about an hour or so sleep last night, so tracking is off.
My comment about quoting isn't snide, it's exhaustion/laziness on my part. :o

Page 11, second column third 'bullet' point paragraph BRB....
"...Infantry models can also be turned to face their targets in the shooting phase, so don't worry about which way they are pointing at the end of their movement phase...."
It really is a caveat, as you TECNICALLY are supposed to be facing your models (by all the LOS descriptors on page 16 etc...) your target. They throw this in so that people aren't being Ana# retentive about your infantry movement like you absolutely HAD to be in 2nd edition TLOS, or you'd create your own fire shadows.

It's important because pivoting in last edition WAS allowed for vehicles, and they specifically take that away for 5th. The CSM dex was written at the end of 4th, but before they had 5th 100% down...so the Chaos Dread falls into a crack in the sidewalk (so to speak) with regard to rules.

(oh, and they weren't as clean in 4e about defining arcs for walkers, so it could matter...I don't have my 4e book handy, so I can't reference HOW specific they were to it) :(

[Nabterayl]

(oh, and they weren't as clean in 4e about defining arcs for walkers, so it could matter...I don't have my 4e book handy, so I can't reference HOW specific they were to it) :(
But they were. Page 64 of the 4th edition rulebook said that "weapons mounted on walkers can fire in a 180-degree forward arc" and had an accompanying diagram. So even in 4th, if you're right, there would never be any need (or indeed, any ability) to pivot.

[Exitus Acta Probat]

N:
Thx...I seem to have lost my 4e book!
Didn't remember it as clear, glsd to know!
Doesn't preclude the step clarifcation though...just calls into question validity or bad wording...and it can't be the latter, GW NEVER does that! (Rofl)

It really isn't a huge deal, just makes a sucky unit a little less sucky, but I really do believe it works that way! :)

[Nabterayl]

Doesn't preclude the step clarifcation though...just calls into question validity or bad wording...and it can't be the latter, GW NEVER does that! (Rofl)
Well, there's a difference between ambiguous wording and an operative provision that is literally never used. At least in 5th edition there's a very small degree of parallax where you might want to rotate a walker a couple of degrees to bring both weapons to bear on a target that is only visible to one. In 4th edition the pivoting in Fire Frenzy would literally never be used if a vehicle was only allowed to target units that its weapons can see. GW writes rules that admit of more than one construction, and it writes rules that very few players will ever want to use, but I'm not convinced that it writes rules that are literally meaningless surplusage.

Of course, you're quite right that in 4th edition vehicles could pivot before they declared their target, so I see the argument that Fire Frenzy is written the way it is to prevent that. However, that means that the "very specific sequence" you hypothesize amounts to not pivoting on the spot, which is a bizarre way to phrase things even for GW. "Pivot on the spot" is sufficiently different from "do not pivot on the spot" that it seems more true to the rules to me to invent a distinction between vehicle LOS and weapon LOS.


I really do believe it works that way! :)
That's totally fair. I think we've probably worked this thread as much as it's going to be worked, so I'll thank you for the debate and move on unless anybody has something new. Been a pleasure.

[Exitus Acta Probat]

That's totally fair. I think we've probably worked this thread as much as it's going to be worked, so I'll thank you for the debate and move on unless anybody has something new. Been a pleasure.

Ditto...
every time I have a rules discussion/debate, if nothing else I learn more about how I actually see the rules interact...and how others' viewpoints coincide or conflict. Almost never fails to be at least a little illuminating.
Thanks