LOS along a Hexside Hill Crest Line

Rob MacDonald

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Gentlemen,

I recently played J157 Rage Against the Machine, and encountered for the first time Hill Crest Lines that run right along a Hex Spine.
In light of the rule Precedence Rule (last line in the ASLRB Introduction) I am not sure at all whether the LOS (from D1) to a lower
level (to N1) can be traced along the Hexside Crest Line.

B9.61 … A Hillside wall/hedge (including both its depiction and its associated Hexside; 9.1) is ignored (…) when determining whether
or not LOS exists …

The C1/C2 Hexside will be Level 0 in C1 and Level 1 in C2. B9.61 states that the Hexside is ignored, basically moving the C2 Crest
Line off of the Hexside.

B10.2 … a unit may trace LOS to a lower level only if the higher unit traces it LOS through a Crest Line as it leaves its hex …

The high numbered rule B10.2 stipulates that LOS must cross a Crest Line before leaving its hex, but the C1/C2/D1 vertex
is at Level 1 from the perspective of D1, so there would be no LOS to the lower locations.

At least that is how I would assess the situation. I’d appreciate comments that will clarify this situation for me.

Rob
 

klasmalmstrom

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Remember that the Crest Line is considered to be where the Level 1 terrain meets the wall depiction, which might not be on the actual hexside.

B9.61 (last sentence):
"...If a hill Crest Line ends at a Hillside wall/hedge, the line along which the hill depiction meets the wall/hedge depiction is considered to be the actual Crest Line."
 

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As Klas says, the crest line is where the upper-level-colored terrain meets the wall. You real problem is the orchard. Inherent terrain like orchard is considered to rise from the level of the ground, and in a crest line hex, there are two levels of terrain. In the center part of the hex, the orchard rises from level one to level two, but on the lower parts of the hex beyond the crest line, the orchard rises from level zero to level one. If orchards are in season, the LOS is "plateau-ed" along that hexside. If orchards are not in season there will be a +1 hindrance to the LOS.

I believe the rules for this is in B10.2, but NRBH to double-check.

JR
 

Rob MacDonald

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Thanks guys,

I am still not clear on how B9.61 works.

The example for this rule says that the 436 has LOS from its hex 25W5 to 25Y5, and this LOS
is along the Hillside Wall Hexside, the wall not being considered the crest line. This seems
to me counter to what Klas is saying. If the wall depiction is considered the actual crest
line, then there should be no LOS from 25W5 to 25Y5.

JR point about the Orchards now originating from two different level in C2 is very interesting.
I never considered this. But if the Orchards were transformed to Open Ground would there be
LOS along the C1/C2 hex side? If the Wall does not exist, as stipulated by the first two sentences
in B9.61, does the Hillside Crest Line along the C1/C2 block 'plateaued' the LOS from D1? This LOS
has not crossed a Crest Line before it exits the D1 hex. If the Wall continues to exist, then the
LOS from D1 is definitely blocked 'plateaued' because the Wall depiction is considered an extention
of the Level 1 Crest Line, according to the last sentence in D9.61.

Using Board 25, does LOS exits from 25V6 to 25X3? Yes if the Wall is ignored. But what about the
reciprocal LOS from 25X3 to 25V6? This LOS would be blocked by the Wall because the LOS 'ends' at
the Wall.

Rob
 

jrv

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Thanks guys,

I am still not clear on how B9.61 works.

The example for this rule says that the 436 has LOS from its hex 25W5 to 25Y5, and this LOS
is along the Hillside Wall Hexside, the wall not being considered the crest line. This seems
to me counter to what Klas is saying. If the wall depiction is considered the actual crest
line, then there should be no LOS from 25W5 to 25Y5.
Both Klas and B9.61 are saying the crest line is where the wall depiction meets the higher-level terrain depiction. The wall depiction itself, except that line at the edge, is at the lower level. The higher level terrain is level one, and where that darker brown color meets the wall is the crest line. The crest line on the X4/X5 hexside is inside the hex by a millimeter or so, and is just above the "X5" label.

JR point about the Orchards now originating from two different level in C2 is very interesting.
I never considered this. But if the Orchards were transformed to Open Ground would there be
LOS along the C1/C2 hex side?
If there are no orchards (or if the orchards are out of season, or if the target is at level one or higher), there is a LOS along the C1/C2 hexside.

If the Wall does not exist, as stipulated by the first two sentences
in B9.61, does the Hillside Crest Line along the C1/C2 block 'plateaued' the LOS from D1? This LOS
has not crossed a Crest Line before it exits the D1 hex. If the Wall continues to exist, then the
LOS from D1 is definitely blocked 'plateaued' because the Wall depiction is considered an extention
of the Level 1 Crest Line, according to the last sentence in D9.61.

Using Board 25, does LOS exits from 25V6 to 25X3? Yes if the Wall is ignored. But what about the
reciprocal LOS from 25X3 to 25V6? This LOS would be blocked by the Wall because the LOS 'ends' at
the Wall.
There is also a LOS 25X3 to 26V6. Again, the wall depiction is at the lower level and the crest line is where the upper-level terrain depiction meets the wall depiction.

JR
 

Rob MacDonald

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I now see the source of my confusion. I was considering the crest line was to be on the edge of the
Wall depiction closest to the lower level. You are saying "where that darker brown color meets the
wall is the crest line". I was considering the Wall to be at higher Level as stated in 9.62, and
ignoring the wall resulted in the higher level (the darker) terrain to exist where the ignored Wall
use to meet the lower terrain. If the Crest Line is accually where the higher terrain meets the wall,
then the Wall seems to be hanging in space - an ASL terrain oddity.

Rob
 

Tuomo

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Revisiting this, sorry.

Part of Board 4a is shown below. I believe the L11-M12 Wall is a Hillside Wall. B9.61 says the crest line in L11 is where the wall begins. But then B9.62 says "A Hill‑side wall/hedge is always at the higher of the two Base Levels it lies between, and is treated as a normal wall/hedge when calculating the TEM of targets at ≥ the wall/hedge's base elevation...." Which seems to say the L11-M12 Wall is sitting on Base Level 1. What am I missing? Should B9.62 be read as "When considering LOS/TEM between units that are both on the higher Base Level of the hillside wall/hedge, the hillside wall/hedge is considered to rise from the higher Base Level"?

30705
 
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Bill Kohler

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Here is the note I made for myself after my last deep dive into the Hillside Wall rules.

Use paragraph B9.61 when answering LOS questions (only!); use paragraph B9.62 when answering TEM questions (only!).
 
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klasmalmstrom

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Part of Board 4a is shown below. I believe the L11-M12 Wall is a Hillside Wall. B9.61 says the crest line in L11 is where the wall begins.
I think using where the wall depiction begins is just a convenient way of defining/describing where the Crest Line is considered to be.

Separate from wall itself which is, as you note, considered to be at the higher level. ASL terrain abstraction and all that.
 

PresterJohn

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In reading about the hexside walls, they appear to be hanging in space above the hexside. This allows for a line of sight underneath them too.
 

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In reading about the hexside walls, they appear to be hanging in space above the hexside. This allows for a line of sight underneath them too.
They aren't hanging in space, but the above is explicitly stated in the EX, yes.

30706
 

PresterJohn

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They aren't hanging in space, but the above is explicitly stated in the EX, yes.

View attachment 30706
The example does make in fact it clear that the wall as illustrated is hanging in space above the hexside, at least in so far as writing notional code for the drawing of LOS is concerned.
You may have another "analogue" interpretation of the lay of the terrain unconstrained by centre dots and hex lines, but the "digital" interpretation is that the wall as drawn is hanging in space.
 

zgrose

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Just working with the tools the rulebook has. You're "seeing" the wall hanging over the hexline. The game doesn't even have the wall anywhere near the line. :)

30707
 

Bill Kohler

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Revisiting this, sorry.

Part of Board 4a is shown below. I believe the L11-M12 Wall is a Hillside Wall. B9.61 says the crest line in L11 is where the wall begins. But then B9.62 says "A Hill‑side wall/hedge is always at the higher of the two Base Levels it lies between, and is treated as a normal wall/hedge when calculating the TEM of targets at ≥ the wall/hedge's base elevation...." Which seems to say the L11-M12 Wall is sitting on Base Level 1. What am I missing? Should B9.62 be read as "When considering LOS/TEM between units that are both on the higher Base Level of the hillside wall/hedge, the hillside wall/hedge is considered to rise from the higher Base Level"?

View attachment 30705
Use the text of B9.61 when answering LOS questions, and B9.62 when answering TEM questions. Do not try to reconcile the two rule paragraphs with each other: they address two different questions.

B9.61 says when checking whether an LOS exists, the crest line is along the line between the Wall depiction and the rest of the hex (and the Wall is ignored if elevation between observer and target is >=1 l level).

B9.62 says when figuring TEM, the Wall only affects units at the Wall's base elevation, which for TEM purposes is at the higher base level.

E.g.: when figuring LOS, the Wall is at the lower elevation; when figuring TEM, the Wall is at the higher elevation. Don't mix the two because the two rule paragraphs conflict as to where the Wall is. Notice especially the Titles of the two rules: "LOS" and "Elevation, TEM, & Wall Advantage". This is a place where you shouldn't overthink it.
 
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Bill Kohler

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They aren't hanging in space, but the above is explicitly stated in the EX, yes.

View attachment 30706
This is the full note I wrote myself after wrestling with this very case:
B9.61 EX: Consider the 4-3-6 LOS to Y5: By the first sentence of B9.62, this wall is a level 1.5 obstacle, although the first sentence of B9.2 allows the LOS, as--seemingly--does the last sentence of B9.61 and the last paragraph of the B9.62 EX. Would the wall TEM apply to a shot against Y5? A: The 2nd sentence of B9.62 says no, and the last sentence of B9.62 EX verifies that: so no TEM. Why? Simple: use paragraph B9.61 when answering LOS questions (only!); use paragraph B9.62 when answering TEM questions (only!).
 
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zgrose

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Personally, I think hillside bocage is far more problematic than whatever is tripping people up on hillside hedges/walls. But that's an issue for another thread...
 

Tuomo

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This is a place where you shouldn't overthink it.
Unfortunately, we do need to be clear so that VASL gets it right. Not only in the normal base case, but also when trying to implement overlays for "All walls/hedges are Bocage".

Anyway. Your advice is good, thanks.
 

Bill Kohler

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I observe that . . .
--The last sentence of B9.61 says [implies] the Wall is at the lower elevation.
--The first sentence of B9.62 says the Wall is at the higher elevation.
--The second sentence of B9.62 treats the Wall as not existing for fire from 25W5 to Y5.

It feels contradictory, but if we apply the rule paragraphs according to their titles, e.g., "LOS" and "TEM", then at least the application is clear.
 
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zgrose

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--The last sentence of B9.61 says the Wall is at the lower elevation.
"If a hill Crest Line ends at a Hillside wall/hedge, the line along which the hill depiction meets the wall/ hedge depiction is considered to be the actual Crest Line."

It doesn't say anything about the wall's base level. It tells you where the Crest Line is.

Anywho, exiting this thread.
 
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