Wargames Rules For Mid-18th Century Battles In Central Europe (Abbreviated & Updated)

I AM updating the rules ahead of our refight this month of the Battle of Chotusitz. Alterations have been made to Movement, Characteristics and Command & Control (which is being used instead of the normal Turn Sequence). Below is an abbreviated summary of the rules with the updated bits italicised.

COMMAND & CONTROL
Bob Cordery, in his recently published The Portable Wargame, has devised a system baring similarities to Bob Jones' Piquet rules but using ordinary playing cards.

Bob Cordery's The Portable Wargame is the latest addition to my wargaming library

He uses it for solo battles but I think it could work just as well for normal games, and I intend to try it with the help of my regular wargaming opponent.
Here is the system, which I have slightly adapted to suit my circumstances.
Begin by allocating one player's army the red cards and the other the black ones.
1. Take the number of units, including the general, that the red army has, and divide by two, rounding up if not a whole number. The result is the army's median playing-card value.
2. Remove from two packs of ordinary playing cards the red median cards and the ones immediately higher and lower (you could also use one pack but designating, say, the aces, 2s and 3s as wild cards).
For example, if the red army has eight battalions of regular foot, six squadrons of horse, three guns, a light infantry unit and a general, it has 19 units, giving a median value of 10 (9.5 rounded up). Accordingly, remove the red 10s, 9s and jacks, giving 12 cards in all (remember, we are using two packs).
3. Repeat the process for the black army, giving a further 12 cards. Add two jokers, and shuffle well.
4. At the start of each turn, reveal the top card. The colour and number indicate who gets to activate how many units in that phase of the turn. For example, a red jack would mean the red player could activate 11 units.
The player must spend activation points in the following order: 1) units retreating, 2) guns firing, 3) other movement, 4) musketry. Once he has used his activation points, or runs out of useful moves, any melees are resolved.
5. Turn over the next card for the next phase, repeating until a joker is revealed. A joker ends the turn, after which all the cards are shuffled and the next turn starts.

MOVEMENT
Regular foot in firing order, ie in line in good order and so able to fire volleys: 6cm
All other foot: 8cm
Limbered guns: 6cm
Heavy horse: 10cm
Light horse and generals: 12cm
It takes a complete phase for foot to adopt firing order, and they may not fire that phase. Cavalry require half a phase to mount or dismount.
Guns take a phase to limber or unlimber. Pivoting a gun counts as movement (artillery may not move and fire in the same phase), but can be done as part of unlimbering.
Infantry can shuffle sideways at half-speed.
There is no penalty for wheeling or for an about-face of 180 degrees, but a second about-face costs half a phase (I previously penalised wheeling of more than 45 degrees but have decided this is a case of double-jeopardy as wheeling is slow enough anyway thanks to the ground that has to be covered by troops on the outside of a pivot. I have also removed the ban on wheeling during the second half a move aimed at making melee contact.),
All troops can pass through friendly light infantry without penalty providing they have enough movement to take them beyond the light infantry. Similarly, light infantry can interpenetrate any friendly troops.
Only one unit can contact each face of an enemy unit.
The Variation
Roll a die every time a unit is moving 75 percent or more of its movement distance for that phase.
6: add 25% to the distance covered
2-5: no change
1: subtract 25% from the distance covered
Terrain
Players should decide before a game how hills, woods, rivers, etc affect movement. Alternatively, the effect of, say, a river can be determined by dicing when a unit reaches the river's banks.

MUSKETRY
Troops can fire within a 45-degree arc of the front of their base.
Musket range: 8cm
Carbine range: 6cm
Roll one die for each 25 percent of a unit's effectiveness remaining and in a single line of bases,.
Minimum score needed for a hit:
Regular foot in firing order: 4
Light foot: 5
Dismounted light horse (except for lancers), and regular foot not in firing order: 6
Subtract 1 from the score if the unit moved during that phase.
I have removed the ability of horse to fire while mounted. Such an action would be fine in a skirmish game but is not appropriate for a squadron en masse in a large mid-18th century battle.

ARTILLERY
Canister range: 0-6cm. Roll one die (halve the score if the unit's effectiveness has been reduced to 50% or  lower).
Roundshot range: up to 24cm. Roll one die and halve the score (halve again if unit effectiveness is 50% or lower).
Halve the final score to get the potential number of hits. Fractions are rounded to the nearest whole number, but an exact half is diced for with a 50-50 chance of being a hit.
Dice for each potential hit, needing a 4 or more to score a hit on foot or horse, a 6 if the target is a gun.
A gun on a hill can fire roundshot over the heads of friendly troops who are at least two contours lower and are nearer the gun than the gun's target.

MELEES
A melee happens when the bases of enemy units come in contact.
There is no bonus for charging (the precise details of how units came to clash is considered a tactical detail below the control of an army's commanding general) but there are restrictions on who can charge whom.
Foot may not charge horse.
Artillery and light infantry never charge and never inflict casualties in a melee. The one exception to this rule is that light infantry in a wood or built-up area melee as regular foot.
Artillery may only be charged if it has no friendly close-order foot within 4cm. Artillery is automatically eliminated in a melee.
To resolve a melee, roll the following number of dice per 25 percent of a unit's effectiveness remaining.
                            Enemy unit
                            Hvy Cav...Lance...Other Lt Cav...Cl Ord Inf*...Cl Ord Inf#...Lt Inf
Own unit
Heavy Cav                1              2                 2                     1                    3             2
Lancers                      1              1                 1                     1.5                 4             4
Other Lt Cav             1              2                 1                     1                    2             3
Close Order Inf          1              1                 1                     1                    1             1
*in firing order and attacked frontally.
#all other close-order infantry.
Throw an extra die per 25 percent effectiveness when attacking in flank or rear (for first round of meleeing only), on higher ground, defending a river bank or defending a built-up area from troops outside the built-up area. These bonuses are cumulative. Round up or down as for artillery fire.
Each potential hit becomes an actual hit on a throw of 4 or more.
After a round of meleeing, the side suffering more hits that phase, including any inflicted by firing, retreats a full move, with the usual possible distance-variation adjustment, and ends with its back to the enemy.
If the number of hits is equal, there will be another round of meleeing at the end of the next phase.
A retreating unit is eliminated if its retreat is obstructed by another unit that is not light infantry or artillery. If the obstructing unit is of the same side, it must take a morale test unless it is a mounted unit retreated into a by a foot unit.

SAVING THROWS
A hit suffered from firing or meleeing usually reduces a unit's effectiveness by 25 percent, but some troops get a saving throw.
Roll a die for troops behind cover, cancelling a hit on 4 or more.
Cuirassiers get an extra saving throw thanks to their armour, cancelling a hit on a 6.

MORALE
Test when a unit loses 25 percent effectiveness or more from firing, or loses a melee.
Roll a die. If the following score is not made, remove a further 25 per cent effectiveness.
Elite: 3.
Regular: 4.
Poor, militia: 5.
A general may be attached to any unit. Such a unit adds 1 to a morale throw. The general may switch units but is eliminated if the unit he is with is eliminated.
A unit adds 1 to its morale throw if it has a friendly unit directly behind and able to reach it in two phases by normal movement (such a friendly unit can only give support to one unit). Exception: light infantry and artillery units cannot give support in this way.
A unit that loses 25 percent or more effectiveness from firing, and fails the resulting morale test, retreats a full move - with the usual possible distance-variation adjustment - and ends with its back to the enemy.
A retreating unit is eliminated if the first move of its retreat is obstructed by another unit that is not light infantry or artillery.
If the blocking unit is friendly, it must take a morale test, unless it is cavalry retreated into by infantry.

RETREATING UNITS
A retreating unit will be diced for at the start of that player's each subsequent phase, needing a 5 or better to return to normal action. A general present with the unit adds 1 to the die throw.
Note that elite units are treated the same as other units - if they broke in the first place, something very serious must have happened to them.

ARMY CHARACTERISTICS
For Chotusitz:
Austrian foot and Prussian horse had improved since Mollwitz.
Accordingly, Prussian foot have only a 50:50 chance of adding 1 to each musketry throw.
Prussian horse, although now much more of a match for their Austrian counterparts, are not allowed any elite units.
Frederick the Great adds 1 to Prussia's median card value (see Command & Control). But this is cancelled because many of the Prussian troops had to be force-marched to get into position and so were fatigued.