KGP Blind Hex LOS

[grabowbe]

Is Y10 a blind hex from a ground level (up-slope) AA15 firer due to the crest line in Y11 (5 hex range from AA15).

Y10 Level 3
Y11 Level 4
AA15 base Level 5 (firer up-slope level 5.75).

Y11 crest line being 5 hexes from AA15 should create one blind hex.

I think that the AA15 hight 1.75 levels above the Y11 base level is not enough to lower the blind hexes to zero.

(the Z12 Orchard is Out of Season, but the firer can see over this without hinderance, so is not considered in this example)

 

[Doug Leslie]

I think you are correct.

A6.42 For every full-level elevation advantage > one level over an obstacle, decrease the number of Blind Hexes created by that obstacle by one, to a minimum of one [EXC: non-Cliff Crest Lines may have their Blind Hexes reduced to none by sufficient elevation advantage; B10.23].

P2.3 LOS: Slopes are neither obstacles nor Hindrances. Being Up-Slope affects LOS only in that an Up-Slope Location is treated as being ¾ of a level higher than normal to LOS that begins or ends in that Location and crosses an Up-Slope hexside of that Location.3 Thus, barring other obstructions to LOS, an Up-Slope unit—even if not in a hill Crest-Line hex—can trace a LOS across an Up-Slope hexside of its hex to a lower elevation (i.e., across a hill Crest Line) and/or over (B.4) obstacles and Hindrances whose topmost obstacle/Hindrance height is < the Up-Slope elevation of the viewing unit [EXC: entrenched LOS restrictions would still apply as per B9.21, as would wall/hedge TEM as per B9.3 (see also 6.2-.3)]. Otherwise, being Up-Slope or Down-Slope itself has no effect on LOS (e.g., slopes are ignored if the LOS goes through their hex or along their hexside, and also when calculating an A6.41-.43 increase or decrease in the number of Blind Hexes caused by an intervening obstacle). Being Up-Slope itself can neither grant HA nor allow an Up-Slope unit to make a HD attempt. The presence of ≥ one slope hexside does not change the elevation of that hex's Base Level.

 

[Bill Kohler]

I concur.

B10.23 says, "A lower level non-cliff Crest Line creates a Blind Hex to a higher level viewer only if that Crest Line is at least five hexes away from that viewer and the next hex along his LOS has a lower elevation than that of the Crest Line hex."

By A6.41, you have one Blind Hex, since you're exactly one multiple of 5 hexes away from the Y11-Y10 crest line: "For every multiple of five hexes (FRD) to a full level obstacle, increase by one the number of Blind Hexes created by that obstacle."

You're looking down over a second crest line that lies between hex Y11 and hex Y10. By A6.43, you're at an elevation of 1.75 above the Y11-Y10 crest line: "if the Blind Hex is created solely by a Crest Line (B10.23), only any difference > one is added since a difference of one level is necessary for a Crest Line to even exist". You are 2.75 levels above Y10, but you only count your elevation advantage as being 1.75 levels because the obstacle in this case is the Y11-Y10 crest line, which is 1 level above the level of Y10, so you have 1.75 levels of elevation advantage over the Y11-Y10 crest line.

By A6.42, you can possibly reduce all Blind Hexes to zero if you have enough elevation advantage: "non-Cliff Crest Lines may have their Blind Hexes reduced to none by sufficient elevation advantage". But by A6.42, an elevation advantage of 1.75 levels doesn't reduce the number of Blind Hexes: "For every full-level elevation advantage > one level over an obstacle, decrease the number of Blind Hexes created by that obstacle by one".

So hex Y10 is a Blind Hex, but hex Y9 would not be (if the Woods in Y10 do not block the LOS).

[I posted an earlier flawed analysis, overlooking B10.23, and so got befuddled. Apologies.]

 

[grabowbe]

Thanks to you both for your excellent analysis! I had seen the earlier posts on this topic and was starting to question myself, since the replay and the hinderance discussion did not mention Y10 as a blind hex. That clears it up for me - so to speak.

 

[Bill Kohler]

If your unit were on Level 1 of the building in AA15, then hex Y10 would not be a Blind Hex, and that would be true whether or not AA15-AA14 were an Upslope hexside. For then you would be at an elevation advantage of 2.75 [or an elevation advantage of 2.0 without the Upslope]: "For every full-level elevation advantage > one level over an obstacle, decrease the number of Blind Hexes created by that obstacle by one".

 

[grabowbe]

If your unit were on Level 1 of the building in AA15, then hex Y10 would not be a Blind Hex, and that would be true whether or not AA15-AA14 were an Upslope hexside. For then you would be at an elevation advantage of 2.75 [or an elevation advantage of 2.0 without the Upslope]: "For every full-level elevation advantage > one level over an obstacle, decrease the number of Blind Hexes created by that obstacle by one".

Yes - I agree. Thanks, B

 

[Stewart]

HoB resources give great examples such as these.