Reverse Vehicle Bypass Movement-VCA

[Stewart]

This is a "What came first, the Chicken or the Egg?"
and a VCA question.

Vehicle REV BP @ M4: Focal Point is as labeled.


Vehicle Rev BP along the L4/M5 hexside.
Does the unit change CA FIRST?
Figure 2:



or does it back up first THEN change CA?
Figure 3


What CA would a shot from O5 on the CA 1MP expenditure have on Figure 2 / Figure 3 (depending on the process)?

FIGURE 4 FIGURE 5
OR

A shot coming from the FRONT Might make a difference from a FRONT or SIDE shot whichever the Rotation came first on the FIRST MP expended.

I.e. do you change CA or Back up for REV move multiplier THEN CA change?

 

[Sparafucil3]

I.e. do you change CA or Back up for REV move multiplier THEN CA change?

See D2.33. The VCA change takes place first. If you cannot complete the move, you are left where you started the move at.

The target facing is a little more problematic. Since you're still at the same CAFP, there is only one way you can legally be in that Location and I think you are hit in the Front. It is a little less clear to be fair. -- jim

 

[fanatic+1]

When you are in reverse the CAFP is based on the rear of the vehicle. Thus the instant you spend a start MP in reverse while in bypass your CAFP instantly changes allowing DFF on the start MP. Then the CA change and move to a new hex and vertex happens before DFF Allowed by that move. Not sure I understand question.

 

[Sparafucil3]

When you are in reverse the CAFP is based on the rear of the vehicle. Thus the instant you spend a start MP in reverse while in bypass your CAFP instantly changes allowing DFF on the start MP. Then the CA change and move to a new hex and vertex happens before DFF Allowed by that move. Not sure I understand question.

I do not think that is true.

D2.32 VCA & TARGET FACING: ... When using VBM, the vehicle counter is placed on the hexside being traversed so that it straddles the hexside, with the VCA corner of the counter resting on the vertex of that hexside in the direction the vehicle is facing. This vertex is called the Covered Arc Focal Point (CAFP) and is the point in the hex where all fire to and from the vehicle is traced while using VBM or Stationary Bypass in that hex.

The more I read D2.33, the more convinced I become the attack takes place at 1MP but as if it has not moved.

D2.33 VCA CHANGES: ... If Defensive First Fired upon or Immobilized before it can complete its move, it is considered to be at the same CAFP and Target Facing last occupied before the VCA change. ...

Having spent 1MP to Change CA, the DEFENDER elects to fire on the AFV. At this point, it has not completed it's move (it still has MP's to spend to get to the next hex-side). Since it hasn't completed its move, D2.33 kicks in and it is considered to be at the last CAFP it occupied.

If you think about it (and Stew's pictures above capture this), there are no legal placements for the vehicle if you don't presume this. I believe this is a nod to hex-based play. -- jim

Edit to add:

D2.11 VCA CHANGES: The Vehicular Covered Arc is the CA (C3.2) of a vehicle based on the front of that vehicle. ...

Adding this here to confirm the VCA of a vehicle does not rely on direction.

 

[Philippe Briaux]

The more I read D2.33, the more convinced I become the attack takes place at 1MP but as if it has not moved.
Having spent 1MP to Change CA, the DEFENDER elects to fire on the AFV. At this point, it has not completed it's move (it still has MP's to spend to get to the next hex-side). Since it hasn't completed its move, D2.33 kicks in and it is considered to be at the last CAFP it occupied.

I agree.

 

[Philippe Briaux]

When you are in reverse the CAFP is based on the rear of the vehicle. Thus the instant you spend a start MP in reverse while in bypass your CAFP instantly changes allowing DFF on the start MP. Then the CA change and move to a new hex and vertex happens before DFF Allowed by that move. Not sure I understand question.

D2.32 Is LOS drawn from the front CAFP in ALL cases for both fire from and to the vehicle in bypass? Even if the vehicle is in reverse motion?
A. Yes. Yes. [J1; Mw]

 

[fanatic+1]

I don’t think you get a shot on a vehicle doing a bypass turn and move along a new hexside until after it has completed the move. The VCA change and movement to the new hexside is one combined MF cost.

 

[klasmalmstrom]

I don’t think you get a shot on a vehicle doing a bypass turn and move along a new hexside until after it has completed the move. The VCA change and movement to the new hexside is one combined MF cost.

You do get a shot in this situation.....D2.33 last sentence.

 

[Sparafucil3]

I don’t think you get a shot on a vehicle doing a bypass turn and move along a new hexside until after it has completed the move. The VCA change and movement to the new hexside is one combined MF cost.

What @klasmalmstrom said. -- jim
Edit to add: See the Example with D2.33. It specifically says "It may now spend one MP to change its VCA, plus two MP to continue VBM in K2 along the K2-J2 hexside ...". The CA and hexside movement are two separate movements and you can fire on either.

 

[fanatic+1]

2021 is not starting out well for demonstrating my rules knowledge, but is starting out well for learning. Thanks everyone.

 

[Stewart]

Any answers to the timing???

 

[Stewart]

So,
Image 4
Or
Image 5

 

[Philippe Briaux]

Image 4 (wrong)

 

[Sparafucil3]

Any answers to the timing???

You spend one to turn your VCA. Your opponent fires on that MP. Since you haven't completed your move, they fire at you in the original position to were in to start the MPh. They only get one MP of shooting (i.e. a Gun that get's ROF will only get to shoot at you once but more than one Gun could shoot). The rule cite for this is D2.33, last sentence ( If Defensive First Fired upon or Immobilized before it can complete its move, it is considered to be at the same CAFP and Target Facing last occupied before the VCA change). -- jim

 

[Sparafucil3]

So,
Image 4
Or
Image 5

Image 4

Neither, your first image depicting the original situation is the correct one. At least, as I understand it, your image 4 is trying to depict the CAFP at M4/M5/L4 for the purposes of firing. That is not correct. For the purpose of firing on the 1st MP, your CAFP remains at L3/L4/M4, just as depicted in the original image. The Gun in K3 could fire on the 1st MP, the one in O5 has no LOS. Assuming it survives all fire on the 1st MP, it would complete its move to the L4/M5 hex-side (CAFP at M4/M5/L4) and now both Guns have LOS and could fire.

FWIW, after backing up the one hexside, both Guns now have side shots. -- jim

 

[fanatic+1]

Looks like 4.

 

[fanatic+1]

I must admit that learning a vehicle in reverse still uses the CAFP based upon the front of the vehicle and that changing VCA and making another bypass move is not a combined MP expenditure has blown my mind. I am still trying to wrap my head around how to determine the facing of a vehicle hit by fire after it declares a change in VCA while in bypass before it moves to the new hexside. Wonky ASL physics. Reminds me of quantum physics, of which I also don't know much.

 

[Philippe Briaux]

For the purpose of firing on the 1st MP, your CAFP remains at L3/L4/M4, just as depicted in the original image.

yes you're right / same CAFP and Target facing.

 

[Sparafucil3]

I must admit that learning a vehicle in reverse still uses the CAFP based upon the front of the vehicle and that changing VCA and making another bypass move is not a combined MP expenditure has blown my mind. I am still trying to wrap my head around how to determine the facing of a vehicle hit by fire after it declares a change in VCA while in bypass before it moves to the new hexside. Wonky ASL physics. Reminds me of quantum physics, of which I also don't know much.

Fortunately for us, the VCA/TCA is easier to figure out. The VCA/TCA for incoming fire uses a different method but it's easier to see and understand. If the vehicle in by-pass were to fire on the vehicle in question, would it be in the Front, rear, or side CA? Which ever one it is in, that's the VCA/TCA that's hit. No need to draw an LOS or anything. This is all in D2.32.

D2.32 VCA & TARGET FACING: ... The Bypass VCA also doubles as the VBM front Target Facing as per the following diagram. The Target Facing of a hit vs a vehicle in Bypass is based on the hex it originated from (not the target hexside crossed as per normal Target Facing; 3.2); to score a rear hit the shot must have originated from a hex in the target’s rear Target Facing. If a firer is itself on a CAFP that separates two adjacent Target Facings of the Bypass target, that fire is resolved as per C.5B. Any shot not originating from within a Bypass Target’s front or rear Target Facing is considered to strike it in the side Target Facing (e.g., a hull hit from a weapon in the hex.

So if you're in the frontal CA of the target, it hits the front. If you're in the rear CA. you hit the rear. If you're in neither, you hit the side. If The turret is rotated, one of the sides or rear aspects becomes the TCA Front, and everything else is worked from there. It's dangerous to turn your turret into the hex your bypassing. The rear aspect of that turret suddenly becomes VERY large. -- jim

 

[Stewart]

Given:

1. VCA changes by a vehicle using VBM are limited to the two hexsides of the VCA at the CAFP
2. A VBM vehicle making a VCA change cannot voluntarily end its MPh in that position; it must move to the next CAFP or reverse into a new hex to its rear.
3. If Defensive First Fired upon or Immobilized before it can complete its move, it is considered to be at the same CAFP and Target Facing last occupied before the VCA change.

SO, #1 supports the Figure 5 Movement (move CA FIRST, as the CAFP is at L3/M4/L4

1. Suggests that the VCA change occurs first BEFORE moving to a new hexside. (note: it does not make a distinction betweeen reverse or forward Movement)
2. States the CA is as if it were not changing facing. i.e. the CAFP diagram of the L4/M5 hexside BUT APPLIED to the M4/L4 hexside (Front CA would eminate from L3) THROUGHOUT all DFF.