From: Markus Stumptner
Subject: Missisiippi Fortress/Clash of Arms ACW combat system
Some time ago we talked about Clash of Arms' area movement civil war
games and I mentioned the problems I had with the combat system. I
have now finally managed to really try the system in the Champion Hill
scenario of Mississippi Fortress, and it's quite clear it just does not
work as history. My hope back then was that the combat system from
the Vae Victis Gettysburg game would be better. Summary for those not
interested in details: the Vae Victis combat system is indeed usable
and appears to work much better than the original system.
For those interested in the VV system, I think the translated Vae
Victis Gettysburg rules are on Richard Fluck's website and they should
contain the combat rules. If there's interest, I can post a description
of the VV CRT in a few days for those who don't own the VV game.
The following is a detailed description of the possible battle outcomes
using the two systems.
MISSISSIPPI FORTRESS
The MF historical notes point out that the Confederates had 20,000 men
engaged at Champion Hill, of which 3,900 became casualties. The Union
had 30,000 men, of which 2,400 became casualties. In game terms, the
CSA had 32 infantry and 8 artillery points, the Union 35 and 8,
respectively. The apparent discrepancy between those numbers appears
to be due to the fact that Union and CSA strength points are valued
slightly differently; also, the 20,000 figure does not include
M.L.Smith's division which was kept in reserve until late in the
battle and would give the CSA 28 points instead. (As we will see,
it's not really relevant for the battle whether he is included or
not.) I did not find any mention of scale in the rules, but will use
a rough approximation of 1 strength point corresponding to 700 men in
infantry units to translate game casualties back into real world
terms. Union strength is roughly evenly divided between XVII and XIII
Corps. The CSA has a 1-2 leader (Pemberton - in this battle only the
2 will be relevant as he is defending), the Union has a 3-2 leader
(Grant), while one Corps has a 2-rated leader.
ORIGINAL COMBAT SYSTEM
To play the battle according to the original MF rules, we will make
the following assumptions: The CSA will take as many infantry losses
as possible (since in the defensible terrain of the Champion Hill
area, artillery gets a multiplier and losing artillery therefore would
reduce strength more quickly). Also, a quick look at the combat
tables will make it obvious that the CSA will gain nothing at all from
using a Counterattack order: it gets a weaker leader, worse odds, and
the terrain benefits are negated. Since the point of giving battle at
Champion Hill was to stop Grant, the defensive order that remains for
the Confederates is Stand in all combat rounds. On the Union side,
either Assault or Advance is possible. We start with Assault.
---
1. Union uses Assault orders. Setup: The CSA sets up in one wing, to
maximize strength. (All units are from the same formation, so all
benefits accrue.) In defensible terrain, we get a strength of 32 +
3*8 = 56 points. The Union could set up either in one or two wings.
One wing means a negative modifier since two corps are mixed, so we
will try a two-wing setup first. XVII corps gets 26 strength points,
XIII corps gets 25 (artillery doubled for Assault). For the sake of
brevity I will not list the individual strength modifiers and column
shifts (leader, terrain, ...) for each round.
ROUND 1. On CIC B we get intensity 3 for Assault/Stand. There are
two separate combats, one for each Union corps since it is a separate
wing. These occur at 1:3 odds due to the various column shifts,
resulting in 2/- losses in both cases. (Note that this result is not
dependent on a dieroll!)
On the FCRT, each wing gets to fire once (giving a slight advantage to
the Union since ist two corps can fire twice on the CSA wing). All
wings fire on the rightmost column. On the average, the CSA will
cause 1 loss to one of the Union corps (we choose XVII Corps here).
Each of the Union corps will cause 1.24 losses on the average to the
CSA. So, after one round of combat, we have the following total
losses over CIC B and FCRT: Union, on the average 5 (3 for XVII Corps
and 2 for XIII Corps), CSA, 2.5 on the average. Note that the FCRT
dierolls will lead to very little variation from this result - 80% of
the Union losses are from the invariant CIC B.
ROUND 2 AND END OF BATTLE. Combat outcomes are unchanged from the
first round, since odds and strength columns are the same. (However,
usually the Union would slip off the rightmost FCRT columns first
since its corps are smaller.) The battle thus ends, assuming average
dierolls, with 10 Union losses (7,000 men) versus 5 CSA (3,500 men).
This is closer to Cold Harbor than Champion Hill.
---
2. Union Advance orders. Next, I tried giving the Union Advance
orders in both rounds instead of Assault. This has the effect of
reducing some losses and the artillery modifiers. In both rounds, CSA
losses will be 2 on the average and Union losses 3. The final outcome
will be 6 losses for the Union (4,000 men) and 4 for the CSA (2,800
men). While the bloodletting is less, the outcome is still clearly in
favor of the CSA, with FCRT dierolling making no big difference.
In both cases, leaving out M.L.Smith's division will not alter the
combat outcomes at all.
---
3. Single Union wing. As a second alternative, I set up the Union in
a single wing opposing the single Confederate wing. That hurts the
Union since the two corps are mixed, so I also put M.L.Smith in
reserve on the CSA side to counteract this at least a bit. Together
with the defensive modifier for CSA artillery in defensible terrain,
this was still not quite enough to give the Union 1:1 odds (51:52),
but I tried this as a variant where I simply assumed the Confederates
were short one point.
Using the actual 1:2 odds with Union assault orders, the average
losses over two rounds of combat were: Union 6 (4200 men), CSA
slightly below 2 (1400 men). With Union advance orders: Union 4 (2800
men), CSA 4/3 (900). Assuming that original numeric odds were 1:1,
the losses with Union assault were Union 6 (4,200 men), CSA slightly
below 4 (2,500). With Union advance, Union 4 (2,800 men), CSA again
4/3 (900). These numbers again speak for themselves.
---
In summary, whichever type orders was given and even with assumptions
that clearly favored the CSA over the actual situation (and over any
decisions a player would make from the game's point of view), the
Union always suffered drastically compared to the CSA and except for
the most beneficial assumptions always suffered far more than
historically. Not only was the historical outcome improbable, it was
effectively impossible. In other words, forget it.
USING THE VAE VICTIS COMBAT SYSTEM
To adopt the Vae Victis combat system, some alterations are necessary.
In the Vae Victis game, leaders are not rated for attack and defense,
but have a strategic value and a separate tactical bonus. Units have
a morale value (e.g., 1 for the Union XI Corps and 4 for the Union I
Corps at Gettysburg). Since such a value is neither given nor
considered in the MF system, I simply ignored it. For leader ratings,
I used the difference between the attacking leader's attack rating and
the defending leader's defense rating. The morale rating is diced
against to determine if one side retreats from battle early or which
side retreats after the battle. The roll is only necessary for a side
if it lost at least 20% of its initial strength. In MF, it might make
sense to use a basic rating of 3 modified by the leader value
difference as above, but I did not examine this closely as I did not
need it for the example.
The system itself (for those who don't know it) lets each side roll on
the CRT to cause losses to the other side. The column is determined by
the strength of the firing side. As in the CoA game, each side can choose
orders before the battle (type of attack/defense). These orders determine
strength and dieroll modifiers as well as whether the battle runs for
1 or 2 rounds and a casualty modifier. (For example, an Assault against a
defense with Stand order will result in doubled losses and two rounds
of combat unless one side is forced to retreat after the first round.)
---
1. Assault orders. For the CSA, I assumed a command of Stand (Tenir), for
the Union, Assault (Assaut General). With a +1 leader mod (for
Grant's 3 vs Pemberton's 2), results in average Union losses of 11
(7,700 men) and 12 (8,400 men) for the CSA. If we use the +2 flank
modifier available in the VV game (since XIII Corps historically
outflanked the main CSA line of defense and would gain the benefit if
played according to the VV rules), losses are Union 11, CSA 16 (11,400
men). So the battle would be extremely bloody although it would
approximate the historical loss *ratio* better than the MF system.
---
2. Advance orders. Concluding that the historical battle was not an
all-out assault in Vae Victis terms, I chose Advance (Assaut limité)
for the Union. Using the flank modifier, this gives on average 5 1/3
losses for the Union (3600 men) and 6 (4,200) for the CSA. Lo and
behold, the historical outcome is actually achievable by assuming
Grant rolled well and Pemberton somewhat less well.
---
3. Stronger leader influence. I then tried a stronger leader
modifier:
- The DRM is modified for both sides by double the leader difference.
However, the difference is limited to the value of the better leader.
(Example: Grant (rated 3) gets a +2 over a 2 leader, a +3 over a 0 or
1 leader. Pemberton (2) gets 2 over a 0 or 1. A '1' leader only gets +1
when facing a 0.) In the example battle, with Grant (3) against Pemberton
(2), it means that the Union gets a +2 and the CSA a -2 (2 times the
leader value difference, and Grant has 3 so the limit is not
relevant).
Given this rule and the flank modifier, the outcome with a Union
Advance is: Union 2500, CSA 5000 on average. This seems to fit the
historical outcome pretty well. Of course, a single battle does not
make history, but assuming the Vae Victis system also works for
Gettysburg, the battle it was after all designed for (and the first
day of Gettysburg is presented as an example of the combat system in
the game rules), that is already a fairly reassuring state of things.
Comments?
Markus
From: Markus Stumptner
Subject: Vae Victis Gettysburg CRT (for Mississippi Fortress series)
Here for those who don't have the Gettysburg game is a short
description of the CRT. The full combat rules are available as part
of Richard Fluck's rules translation on his website, so I only give a
quick overview. Basically, in each round of combat each player rolls
a die to cause losses to the other side depending on his combat
strength. Before combat, each side chooses one of three orders and
the combination of the orders determines whether the combat consists
of one or two rounds and the loss multiplier:
At the end of each round a side that lost at least 20% of its strength
rolls against its morale to determine whether it retreats, thus ending
the combat (unless it has to retreat but can't in which case it is
marked encircled).
The following "tactics table" specifies combat intensity. Each entry
consists of: loss multiplier/number of rounds of combat (e.g., when
attacking with Assault against Hold, losses per round are doubled and
two rounds are fought).
Defender order Hold (Tenir) Delay Retreat
Attacker order (Recul) (Repli)
Assault x2/2 x1/2 x0.5/1
Advance x1/2 x1/1 x0.5/1
Probe x0.5/1 x0.5/1 x0.25/1
Strength modifiers
Artillery combat strength is modified according to orders and terrain
per the following table.
Assault Advance Probe Hold Delay Retreat
Clear x3 x2 x1 x3 x2 x1
defensible x2 x1 x1/2 x3 x1 x1
Cavalry strength is halved in defensible and mountains.
Artillery counts zero in mountains.
In addition, fatigued attacker units are halved and entrenched
defenders are doubled.
Column shift:
Flank attack (attacker entered from 2 areas *on that turn*): attacker 2R
encircled defender (see rules): attacker 3R
defender in mountains: attacker 1L
defender in defensible terrain: attacker 1L, defender 1R
Dieroll modifier:
leader modifier (see my previous posting on this)
attack across bridge: attacker -2
attack across stream: attacker -3
defender in clear: defender +1 (I wonder why, actually)
difference in unit's average tactical value (see my previous posting)
attacker has assault orders: attacker +2
defender has Hold: defender +1
defender has retreat: defender -1
The CRT has the following columns: 1-3, 4-6, 7-10, 11-15, 16-21,
22-29, 30-40, 41-60, 61-80, 81-100, 101-150, 151+
Dieroll range is -1 to 10 (16 plus modifiers), with -1 listed at the
top. The rightmost column (151+) is 2,2,3,3,4,4,5,5,6,6,7,8 and this
is shifted 1 row downwards per column with 2 '1'-result rows following
above the '2' results. The 30-40 column reads
-,-,1,1,2,2,3,3,4,4,5,5. For the three leftmost columns (7-10 column
leftward to 1-3), the upper '2' result is changed to '1'and the upper
'3' to '2' so that the 7-10 column reads -,-,-,-,-,-,1,1,1,2,2,2.
Markus