Simple Method for interpolating combat values

[RLW]

I thought I would make a table that  captures (my latest) interpolation dr conditions  YES means that it is a applicable dr condition - means that  it is a minus only interpolation dr condition and  blank means  neither. FG = fire group and applies if any  unit in FG has condition. OP = opportunity fire, units is used  hereto  refer to combat units and not leaders, in assault "against" refers to the one receiving the AF and "by" refers to the  side  conducting the AF. These conditions have no effect on other normal shifts and are in addition to them.

Having two  or more plus conditions gives the exact same result as only having one, except that the max die roll is treated  as its presented value and not as zero. Same for negative conditions. For example if one had a FO with special abilities and and arty leader with special abilities (see table below) then that plus die roll would  treat  say a 5 rolled on a 5 sided die as 5 and not as 0 (given there were no minus die roll conditions as well).

Having both plus and minus condition  cancel  each other out. So if one has one plus condition and one minus then they cancel each other out and  one rolls both plus and negative die. But if  one has two plus and only one  negative then one would employ the plus only roll, etc. If none of the conditions exist (which will typically be the case) or that the number of plus conditions equals the number of minus conditions so as to  cancel each other out then both the plus and minus die are rolled and added together for the purpose of interpolation. 

If a situation applies to some units in a stack but not all only one interpolation dice  roll is made but the results would be applied to each unit as to what conditions apply to that unit. Thus say a stack of three one unit might be bumped up to the next column, one bumped down, and the other not affected. This is in addition to any normal shifts. BTW if this ever gets too messy one might need to write down on a note  the interpolated results for each unit. 


Interpolation results do not count against +3/-2 shift limits for DF.


Plus Conditions______________________________________DF---DF OP----BF----BF OP-----AF (attacker)---- AF (defender)
1. DF Op fire against  a target that moves greater than 1 hex..................YES                      
2. Assault against a wheeled vehicle (but not MC), 
OT, or non turreted AFV............................................................................... .......................................................YES..................... YES  
3. DF against  target that is lower and adjacent to the firing unit..............YES......YES
4. DF with a MG (in FG) that has a leader with MG special ability................YES.....YES
5. DF if FG has INF and leader has rifle special ability.................................YES.....YES
6. Spotter  has FO special skill ...........................................................................................YES.......YES
7. Arty leader has Arty special skills.....................................................................................YES.......YES 
8. AF by ENG unit on non first AF (see note 1 and 7)............................................................................................YES..................... YES
9. BF against targets in woods (to reflect air burst).............................................................YES......YES
10. AF by leader that has applicable urban or rural leader ability.......................................................................... YES......................YES
11. AF against first AF (see note 1 & 6) ............................................................................................................................................YES
12. BF against wheeled vehicle (includes MCs) or OT AFV.....................................................YES......YES

Minus Conditions _____________________________________ DF---DF OP---B---BF OP----AF (attacker)-----AF (defender)
1. DF against any target in terrain limiting hex (that has no other DF shift). YES    YES
2. AF by any OT AFV  against INF (see note 9).....................................................................................YES........................YES
3. (2x) AF by any non turreted AFV (see note 8)  ................................................................................YES........................YES
4. DF by scouts or Cav (not just horse cav)  at range greater than 1 hex..... YES
5. DF and BF against dug in targets in woods (see note 2)...........................YES....YES......YES.....YES
6. AF against withdrawing  units.............................................................................................................................YES
7. Unit firing at max range ...........................................................................YES....YES......YES.....YES
8. AF against  units all in non good order................................................................................................................YES......................YES
9. AF with INF with no AFVs/inherent AT fire against AFV in clear terrain..................................................................YES
10. DF at INF in river hex (major or minor)...................................................YES.....YES
11. First assault fire. (see note 5)............................................................................................................................YES
12 AF by no leaders or none  in good order............................................................................................................YES
13. Air attack against hex adjacent friendly units (see note 4)........................YES
14. DF fire against IG or Arty with gun shield.................................................YES

note 1. In addition to normal shifts.
note 2. only effect of having  dug in counter in woods (e.g. no +1 shift or first fire). Thus using this rule one can dig in in woods but it only helps one in regard to the  interpolation roll and provides no other benefit. It would cancel out the other rule (rule 9 in the plus conditions).  
note 3. The negative only  die role condition  1 gives terrain that offers no DF shifts such as fields (in season) at least some protection from DF fire . But if the terrain has  one or more negative  shifts this condition does not apply. 
note 4.  This condition reflect the fact attacking from the air targets close to friendlies is difficult and more caution has to be employed.
note 5.  The attacker in an  assault has to be on the move. But less so as the assault develops
note 6. In an assault The defender does not have to move where the attacker initially does so this condition reflects that.
note 7. It always pays to have guys with demo charges (regardless of the terrain), but they have to get close first and hence  this rule only applies to subsequent AF and not the first.
note 8. This conditions counts double, i.e it can cancel out two plus conditions and thus invoke the battle of the zeros rule and give any plus dir roll that boost by reading its max  value as presented and not as zero).
note 9. the idea here is that an OT vehicle  near enemy inf would be so worried about them that it would likely hamper their offensive ability a bit.

BTW, I will try to update this as I play out my test scenario

Obviously any such list as this will reflect one's own personal preferences or biases. But the idea here is not so much on making anything like an definitive list of conditions but rather to just test out the idea in general and see how its works. And most of these I just thought of off the top of my head so no real thought has gone into them, so this is more of a first cut than anything  meticulously thought out and tested. But it shows how having something less potent than a full +1 shift might open the door to  including other secondary factors such as these.

[edit] Here is an optional rule that I  like (but haven't tested yet) that one always rolls both the plus and minus die, but if the situation dictates that only the plus die or minus die is to be used then that other die roll is treated as zero no matter what it rolls. However if it in fact did roll a zero then that other die roll would treat its maximum value not as zero but as its presented value. Thus say the situation called for only a plus die roll of a 5 sided die but that minus die would have been  4 sided die had  the situation called for  both the plus and minus rolls. By this rule one would roll both die but treat the minus die as a zero regardless of what it rolls.

 Say one rolled a 5 and a 3. The 5 (being the max number) would be read as a zero and the 3 (being that the condition did not call for a negative roll) would be read as a zero as well, giving a 0-"0" = 0 result with the " "'s around the zero indicated that is how that die rollis read no matter what the actual roll was. 

But if the minus die roll was a 4 and not a 3 then that would be read as a true zero (being the max value) and that would cause one to read that 5 not as a zero but as a 5 and thus the sum would be 5-0with no " " on that zero for it was a zero that was rolled  . Thus there is a bit more mental gymnastics in this approach but one has the benefit that one always rolls two die  and the conditions  dictate merely how one reads those two die rolls rather than how many die one rolls. thus with this rule there are two ways that the max die roll can be read as that value and not a zero. 

Either form where having two (none countered) conditions  (for either  a plus only or minus only roll) or when one has only one such  (not countered) condition causes that "not rolled" die roll if it rolls a  true zero (i.e. 0) vs merely an assumed zero (i.e '0") to boost that other die roll by replacing its normally read zero with the listed value (e.g. a 5 for a 5dr would be read as a 5 and not as a 0). Also, I just added the case where some conditions count as two (denoted by a 2x in parenthesis in the above table) for this so that if that conditions is present it counts twice in regard to both canceling the other  opposing conditions are  bumping up that other die roll. That said this 2x rule just like the battle of zeros rule  I consider optional in that they  are a bit  more to warp iones brain around when playing, with the basic house rules contributing enough to that  on their own.

And BTW this rule is harder to explain than actual employ. And i like to give each rule a name that helps one remember it so I am calling this optional rule, the battle of the zeros.
  
[edit] I added a new rule 11-14 for conditions to only roll the minus die and cleaned up some of the wording of the other rules. Plus I edited a few more. I guess you can call these living rules, and they ma still be at the represent a bit lively at that, but I imagine that liveliness with fade away after a while.

[edit] BTW, I deleted the previous post in that it is now OBE.