Friday, July 26, 2019

Portable Napoleonic Wargames: Combat Mechanics

A small play test of mechanics.  Both sides rolling '6's'
wasn't much help!
My recent Portable Quatre Bras game, along with the earlier Army (Corps) games (Wavre and Grand Rosiere) have led me to think about ways to obviate combats that (a) guaranteed immunity from harm, and (b) guaranteed susceptibility to harm.  During the course of the Quatre Bras action, the British Guards Division, in column, ran into Foy's Division. 

Foy had the deeper column (3 stands against 2); both could claim a general officer present.  As the combat mechanics stand, there was no way the French could sustain a hit.  As it transpired, the Guards rolled '2' to determined what happened to them; and the French rolled a '1'.

Incident in Quatre Bras action.  French roll of '1' was
still not low enough to register a hit on them.
This seemed to me not an especially desirable outcome.  Why shouldn't the French at least have had some chance of taking a hit?  In the write-ups of those battles, I made certain proposals, but have since decided that they aren't quite satisfactory.  I want to stick as close to the 'spirit' of the original rule set as may be, and felt that my suggestions did that.  But they also seemed rather hard to remember.  So I have had a considerable rethink.

First of all, a reminder of the Portable Napoleonic Wargame Combat Rules.  I'll rearrange the text slightly, but otherwise the meaning is the same.  Close combat is between opposing stands (figure bases) in adjacent grid areas.  Whose turn it is 'initiates the combat' (I infer even if it is an ongoing one).   IThe original rules are in italics, and I have added amendments to these in roman.

Both sides roll a D6 die for their (own) figure base involved in combat and add or subtract any relevant modifiers.

Add 1 to the D6 die roll score for:

  • Each friendly supporting stand in the same grid area as the stand initiating the combat;
  • Each friendly supporting stand in the same grid area as the stand being attacked;
  • If the stand initiating the combat is cavalry attacking infantry or artillery;
  • If a friendly commander or subordinate commander is present in the same grid area as the stand for which the D6 is being rolled;
  • If the stand being rolled for is in contact with the flank or rear of the enemy stand or formation of stands.
Add 2 to the D6 die roll score for:
  • For friendly flanking support stand in the same grid area as the stand initiating combat OR being attack or in contact.
Reduce by 1 the D6 die roll for:
  • Unit is being attacked (or has been contacted) in flank or rear by enemy;
  • Enemy unit or stand is uphill(1) or in cover;
  • For each enemy supporting stand in the same grid area as enemy initiating combat;
  • For each enemy supporting stand in same grid area as enemy being attacked (contacted).
Reduce by 2 the the D6 roll for:
  • Enemy unit is in fortifications (or strongpoints);
  • For enemy flanking supporting stand in same grid area as the stand initiating combat OR being attacked or in contact.
BLUE column vs RED line.  The dark numbers represent
'unsafe' unmodified D6 rolls; the lighter numbers, the 'safe'.
Note 1:  I am disinclined to offer a bonus for being uphill or a penalty for being downhill, whether shooting or in combat.  My own reading seems to indicate that, owing to a tendency, especially among unpractised troops, to firing high, being downhill might actually have been the favourable position, even though at the time it might not have been perceived as such.   That the perception and reality might have been at odds sounds plausible to me, and for that reason am inclined to leave the matter open.

But now we come to the substance of my proposed amendment.  It is this.  When rolling their respective D6s, the players also determine their bonuses (pluses) and penalties (minuses).  The side with the higher 'plus' count adds 1 to his D6 roll, and the player with the higher 'minus' count reduces his D6 roll by 1.  The effect of this is that in no combat is the risk of a hit less than 16%, nor greater than 50% (2).

Note 2: I did consider that the higher minus count reduce his D6 roll by the difference, but for now, prefer the 'gradualist' approach.


1. A single French (BLUE)  stand (figure base) advances 
into contact with a British (RED) stand accompanied by its Division commander (denoted by the flag).  The numbers indicate the D6 scores that will result in a hit being received.

BLUE: D6 score: 2 + 0 (no modifiers) = 2 Hit
RED: D6 score: 1 +1 (GoC Div) = 2 Hit
RED: D6 score: 2 +1 (GoC Div) = 3 Not hit.

 2.  A BLUE column of 2 stands, led by a Division commander, advances into contact with a RED brigade stand also accompanied by its divisional commander.

BLUE: D6 score: 1
Pluses: Goc Div + supporting stand = 2
Minuses: none

RED: D6 score 3
Pluses: GoC Div = 1
Minuses: Enemy supporting stand

BLUE has more 'pluses' so adds 1 to his D6 roll.
RED has more 'minuses' so reduces his D6 roll by 1.

BLUE final score = 1+1=2 Takes a hit (A D6 roll of 2 would have been safe)
RED final score = 3-1=2 Takes a hit (A D6 roll of 4 would have been safe)

3.  A BLUE column of 2 stands, led by a Division commander, advances into contact with a RED Division column also accompanied by a general. 

BLUE: D6 score: 3
RED: D6 score: 1

BLUE pluses: GoC Div + 1 support stand = 2
RED pluses: GoC Div + 2 support stands = 3
RED adds 1 to his D6 score.

BLUE minuses: 3 enemy support stands = 3
RED minuses: 2 enemy support stands = 2
BLUE reduces his D6 score by 1

BLUE final score = 3 - 1 = 2 Takes a hit (A D6 score of 4 would have been safe)
RED final score = 1 + 1 = 2 Takes a hit (A D6 score of 2 would have been safe) 

4.  A BLUE column of 3 stands, led by a Division Commander, advances into contact with a RED line of 2 brigade stands.

BLUE: D6 score: 1
RED: D6 score: 2

BLUE pluses: GoC Div + 2 support stands = 3
RED pluses: 1 flank support stand in hex = 2
BLUE adds 1 to D6 score.

BLUE minuses: 1 enemy flank support = 2
RED minuses: 2 enemy rear support = 2
NO modification to either D6 roll.

BLUE final score: 2 Takes a hit (A D6 roll of 2 would have been safe)
RED final score: 2 Takes a hit (A D6 roll of 3 would have been safe).

Here I'll pause, and add more examples next time.
To be continued...


  1. A quick scan of the additions and subtractions indicates to me that by applying the same modifier to both attacker and defender, you give a double bonus. So for example, giving a flank attacker +1 and the defender -1, you give the attacker what is in effect +2.
    On a D6 based system this is probably too extreme (a 33% bonus). It would only get worse with supporting stands and officers.
    I'd suggest rather than applying modifiers to both, it only applies to one. So flank attacks give +1 to the attacker. If these were cavalry attacking infantry, with support and a General you would be up to +4 or +5. The odds would be in the attackers favour but still allow for lucky dice throws having an influence.
    Support is probably the one that needs to apply to both, but here it could be as simple as whichever side has more stands gets +1.
    Untested I confess.
    It may be worth looking at other D6 based systems (such as DBA) to compare how they handle it.

    1. Hi Neil -
      What I have in mind doesn't quite work the way you mention - at least not 100% - being somewhat ameliorated by the absence or presence of general officers. I think what Bob had in mind that pluses and minuses cancel each other out in some way. But, unless he had it in mind that in some circumstances units might be immune from taking hits, it seemed to me that something had to change to ensure that all combats contained a degree of uncertainty and risk. My proposals reduce the pluses and minuses (which were already there) to 1 only maximum either way, and leaves no unit immune from taking hits. My guiding principle has been to adhere as closely as possible to the intent (as I infer it) of the original combat mechanics.

      There was another issue I wanted to address as well: not so easy this one. It had to do with the 'column vs line' thing. My giving +2/-2 for flank support in the same grid area, the result was that a 2-element line balanced a 3-element column - at least for a while (given that if all the elements have the same SP, the column would STILL be at a long-term advantage).

      We'll see how it goes.

    2. By the way, in the 2-element line vs 3-element column, the net effect for both formations is zero, the pluses and minuses cancelling each other out, at the same time leaving the risks unchanged. I daresay in this particular example that had only pluses been counted then differenced (say) the result would be the same.

      But check out example 4 above. The minuses cancel out; the pluses don't.

  2. These types of addative combat system often demonstrate problems at the extreme end of the scale as the cumulative effect of the dice modifiers is logarithmic, not linear. So +1 on a 4+ is a 33% increase, whereas +1 on a 6+ is a 100% increase!

    You can only really fix this by limiting the total number of modifiers (a maximum of plus or minus three seems to work), use a CRT or just accept that a basic D6 to hit isn't very granular and ignore all but the most important mods.

    1. Hi Martin -
      I hoped that conflating pluses and minuses in the manner I have suggested would mitigate the effects you mention. The end result is that having the advantage in the combat might halve the risk from 2/6 to 1/6 of taking a hit; a disadvantage might raise the risk from 2/6 to 3/6. The counting and comparing is no more onerous (in my view) than the plusing and minusing in many another rule set I have seen.

      I have by no means exhausted the examples, and in fact still have several to work on. This MIGHT mean that the proposals in this posting taking further amendments, we'll have to see.

      Whose move it is might also have an impact, especially in what I see as 'column vs line' situations. The legendary Kookaburra's Khyber has to be examined minutely to determine its nature...

  3. Archduke Piccolo,

    Yet another very interesting and thought provoking post. I want to sit down and go through your ideas in detail, but won't be able to for a few days.

    All the best,


    1. But wait: there's more. I'm not yet sure just how 'needful' these suggestions are. If discussed more of my thinking in my next posting. I've done a little bit of play testing, but they'll require a nice, hefty blowout to see whether I've really added something substantive to the Army Corps level game system.