napoleon's battles at divisional and one-half scales

I am trying to find a Napoleonic rule-set to play minor, i.e divisional, engagements occurring at the Campaign of Leipzig or in any other Napoleonic Campaign. I could use a commercial tactical rule-set (Shako, General de Brigade, Le Feu Sacré ...), a free downloadable set such as Eagles and Glory or the Spanish Serrez les Rangs or one of the myriad of free sets available at the Freewargamesrules site. However, I don't want to waste my quickly diminishing neurons so I pretend to use Napoleon's Battles (henceforth NB) at divisional scale (NBd) whereas making the minimum possible number of modifications.

1. Generalities
Yes, NB is a grand tactical rule set so (1) all the scales (men, terrain and time) must be modified and (2) some things abstracted in the original NB (skirmishers, artillery fire...) as well as other new arising problems (battalion/regiment/brigade commanders and their command radii, casualty assignment...) must be resolved.
I am very grateful to the members of Yahoo napbattles group, Paul McAndrew and Luke Willen, for their suggestions.

2. Scales
2.1. Divisional or Batallion Napoleon's Battles (NBd)

- Men
1/30
- Terrain
1/900 (1 in. to 25 yds.)
- Time
10 min per turn or 6 turns per hour
- Artillery
1 model/4 guns
The general picture of a NB battle is almost maintained in NBd although the combat units are now
infantry battalions, cavalry regiments and batteries. The global effect is a MAGNIFICATION of both battlefield (4:1) and time (3:1) resulting in:
1) A NB infantry 4-figures stand becomes a company (120 men) so a typical infantry battalion will have 4-7 stands.
2) A NB cavalry 4-figures stand becomes a squadron.
3) An artillery battery is composed from 2 or 3 gun models (according to the actual strength of its historical original).
4) All fire distances and command radii must be multiplied by 4.
5) The movement distances remain un-changed since the modifications in terrain (space) and time scales approximately cancel one to another.
For example: a movement of 10 in. in NB implies a speed of 1000yds/30min. In NBd an unit at that speed will march in a turn of 10 min. a distance of 1000*10/30=333.3 yds  or a tabletop distance of 333.3/25=13.3 in.

2.2. One-half or Regimental scale (NB0.5)
- Men 1/60
- Terrain
1/1,800 (1 in. to 50 yds.)
- Time
15 min per turn or 4 turns per hour
- Artillery
1 model/6-8 guns
This is an intermediate solution. All the ranges will be twice the ones given en NB. All the above points and considerations must be adapted to the change of scale. However, the point addressing the Brigade commanders may be not necessary.
1) A NB infantry 4-figures stand becomes a
division (two-companies) (240 men) so a typical infantry regiment will have 4-7 stands.
2) A
half NB cavalry 2-figures stand becomes a squadron.
3) An artillery battery is composed from
1 or 2 gun models (according to the actual strength of its historical original).
4) All fire distances and command radii must be multiplied by
2.
5) The movement distances remain un-changed since the modifications in terrain (space) and time scales
exactly cancel one to another.
For example: a movement of 10 in. in NB implies a speed of 1000yds/30min. In NB0.5 an unit at that speed will march in a turn of 15 min. a distance of 1000*15/30=500 yds  or a tabletop distance of 500/50=10 in.
Onwards, all considerations will be of application to both modificatations, but the actual distances will be given in blue for NBd  and in red for NB0.5.

3. The fire problem
In NB, the so-called infantry fire of the Fire Phase is a combination of the fire of both skirmishing infantry and light divisional guns. That combination is abstracted in NB and neither skirmish infantry nor divisional artillery are represented in the tabletop. However, the use of a bigger terrain scale in
NBd and NB0.5 implies the use of 'real' divisional gun models and skirmish figures.

3.1 Divisional guns
These guns can be represented and treated in a similar way to NB heavy and horse 'normal' batteries: they will fire during the Fire Phase and, like normal combat units, will need to be in command in order to move or change formation. Divisional guns can be commanded by their divisional (or brigade) commander applying the habitual NB command rules. No modification is needed beyond their inclusion in the OOB's. (See below 'Assignment of artillery casualties')

3.2. The skirmish screen
According to NB the skirmish screen extends from the main firing line, until a distance of 200 or 500 yards, depending on the skirmish ability of the troops and their fire arm (musket or rifle). Discounting the optimum firing range of the musket or rifle, around 100 yds., we can conclude that the skirmish screen actually extended from 100 to 400 yds. from the front rank of the formed troops.
In
NBd (NB0.5), skirmishing figures will be placed on the tabletop scattered into the fire area of the brigade, i.e. from the base frontline of their accompanying formed infantry until a distance of 4-16 inches (2-8 inches) or 10-40 cm (5-20 cm). The maximum distance of the front of the skirmish screen to the front of its parent formed unit, is found from the NB firing distance, as given in the game roster:
 

NB fire range (in) Actual distance (yds.) Maximum NBd distance
 (in)
Maximum NB0.5 distance (in)
2 0-100 0-4 0-2
3 0-200 0-8 0-4
4 0-300 0-12 0-6
5 0-400 0-16 0-8


No skirmish figure can stand at a distance lesser than 100 yds.,
4” (2”) or 10 cm (5 cm) from an enemy unit, including other skirmish screens. If an enemy infantry unit moves into combat contact with the skirmishing unit, this must "evade" by making an automatic "evasion move" as soon as the enemy unit makes combat contact. This automatic evasion move must end the combat contact, and also disorders the skirmish screen. This move may not be used to move the evading unit into another combat contact. The enemy unit whose contact causes an evasion may continue moving as if the combat contact never occurred. It is possible to again contact a unit that evaded earliers.

3.3. Skirmish fire
The real effect of the skirmish fire is (and was at that time) an arguable matter. The number of resulting casualties was small and the main achievement of skirmishers was to disorder enemy formed units whereas simultaneously protecting the own from the enemy. To model the effects of skirmishing at divisional scale, I'll try one of the solutions pointed in my Modifications of Napoleon's Battles page. These skirmish house-rules (discussed in the Yahoo napbattles group) were used in my NB Scenarios for the Peninsular War (see the link for Scenarios at right menu) and arisen from the need to discount the effect of divisional guns. The possibilities are:
1) Use an additional negative modifier  to Infantry Fire Factors, OR
2) Modify the ‘Resolving Fire’ Rule so a ‘two losses’ result is converted to ‘one loss’ and a ‘one loss’ is a miss, OR
3) Carry out the infantry fire as usual without any modifier. The resulting losses are not marked on the target unit, but are only used to cause disorder
The last option can be discouraging: too many die-rolling for nothing! and the first one will need further research to find the optimum factor so I'll use the second:
A ‘two losses’ result is converted to ‘one loss’ and a ‘one loss’ is a miss and the disorder in the target unit is assigned as usual.
The change of scale also affects the interaction skirmishers-cavalry. The Fire Modifier for "being not protected vs. attacking cavalry" must be used always than an enemy cavalry unit (attacking or not) could reach the skirmish zone.
All above considerations also apply to cavalry skirmishers.

3.4 Modifications to fire factors
3.4.1 Firing by Skirmishers
Since the fire infantry fire is now only due to skirmishers, some modifications must be made to the fire factors listed in the rules. The following modifiers replace the factors related to the force of the firing unit:
- the unit does not deploy any open order base (only marksmen firing):
'-3'
- the unit deploys 1 base :
'-2'
- the unit deploys 2-3 bases: '-1'
- the unit deploys 4-5 bases or is fully in open order: '+1'
3.4.2 Firing at artillery units
All firing (skirmish and artillery) at deployed artillery units is made with a '-3' modifier
3.4.3 Firing by formed battalions
The '-3' modifier to infantry units not deploying skirmishers becomes is a too strong penalization at small distances.
- the enemy unit is at a distance of
3" (1.5"), 75 yards or greater: "-3"
- the enemy unit is at a distance of
2"-3" (1"-1.5"), 50-75 yards: "-2"
- the enemy unit is at a distance of
1"-2" (0.5"-1"), 25-50 yards: "-1"
- the enemy unit is at a distance
of 0"-1" (0"-0.5"), 0-25 yards: "0" and a close combats will follow.

4. Brigade commanders and other Generals
Because of the modification of scale,
the fighting units in NBd and NB0.5 are batallions or regiments instead of brigades. In NBd at least, the inclusion of Generals de Brigade for the combat units as a last step in the command chain it is necessary. These NBd Brigade commanders will have a command radius extending only to his own brigade and to the divisional battery (?) and their remaining abilities will be assigned according those from the actual brigade generals when known. NBd Division Generals are equivalent to NB Corps Commanders, and NBd Corps Commanders equivalent to NB Army Generals, but usually they will be no present at tabletop. To calculate the value in points for Generals, maintain the above equivalences but without command drops.
If the chosen battle is a divisional affair, the
NBd situation would be similar to a NB battle fought between two non-napoleonic armies, in which divisional commanders are directly commanded by the C-i-C (See, for example, the Salamanca O.O.B).
In the case of NB0.5, the inclusion of Brigade commanders it is not so decisive, and therefore these Generals may be not shown in the table.
 
5. Assignment of artillery casualties
Because of the change of scales,
NBd uses many more guns than NB: Each normal (Reserve and Horse) battery is now represented by two gun models, to which those from divisional batteries (also two models by battery) must be added. This excessive number of guns introduces a distorting effect on casualties so the hitting power for artillery must be decreased. The solution lies on the adoption of the same system than the used for infantry skirmish fire: A ‘two losses’ result is converted to ‘one loss’ and a ‘one loss’ is a miss
In the case of NB0.5, each battery is represented by one gun model but these rule is still necessary to avoid distortions by the presence of divisional guns. 

6. Changes of formation
A NBd turn expands only 10
minutes (15 minutes for NB0.5), a time-length similar to the duration of near almost all  formation changes carried out by battalions or cavalry regiments but a brigade spent many more time to finish its deployment (see the Jeffrey's book cited in the Bibliography). In NB, these battalion and brigade movements are abstracted by subtracting the time of formation changes from their lesser Line movement allowance. The net result is that only very well drilled brigades, will have additional movement allowance left after changing formation.
The simpler way to model that in NBd
and NB0.5 is to consider that all formations changes of individual combat units spend, at least, one turn to complete, i.e. 10 (15) minutes on good terrain. Brigade evolutions will be after made by individual units using their new movement allowances.
This basic duration will be increased if the formation changes were made by units with half-move allowances (two turns instead), or by units moving in rough terrain, which must use their 'Rough Terrain Modifier' of the unit.
Units spending more than one turn to change formation or with no movement allowance left in the turn after changing formation (i.e. units whose Line Movement allowance equals their 'Change Formation Modification Factor') will be considered as "disordered" for fire and combat during that turn ('-3' modifier')

7. Fire and movement
For the same reason than above, a unit moving during a
NBd (NB0.5) turn, 10 or 15 minutes, must be penalized in some way if firing during this same turn. Therefore units moving during a turn (formation changes included) will be considered as "disordered" for fire during that turn ('-3' modifier').

8. Flank and rear attacks
In NB there are not any modifier to be applied to units attacked in flank or rear. The NB designers always have maintained that such things were managed by the Brigade commander and were out of the game scale. Thus, the units attacked in flank or rear were only penalized by not firing the attacking enemies. In
NBd and NB0.5 these attacks can not be abstracted: units attacked in such a way will suffer a '-3' modifier in fire and combat .

Evidently, all these thoughts and wonderings must be carefully play-tested and the next step will be the design or adaptation of divisional Scenarios. See the 'Divisional Scenarios' at the right menu .


Bibliography

Jeffrey G., Tactics and Grand Tactics of the Napoleonic Wars, Ed. by Ned Zuparko, The Courier Publishing Co., 1988

pdf document
 

WHAT'S NAPOLEON'S BATTLES