BACW Design Notes

Fun Interactive Military History

Battles of the American Civil War is my attempt to model Civil War grand tactical combat at a constant scale.  When I read about a battle, I like to have a map and counters to push around to help me understand timing and maneuver issues.  This is the outcome of many years of reading and counter pushing.


This particular ground scale (1 hex = 400 m) was chosen because a unit's fire doesn't historically cover a range farther than the adjacent hex, so fire and shock action can be subsumed as one single combat result (there weren't a lot of pure bayonet charges in the ACW).  Most battles fit on a single 22x34" map or less, which is a convenient size.

Troop scale varies between games. In the smaller and earlier battles, Regiments of 400-1000 men, and sometimes "battalions" (company groups smaller than a regiment) were used as independent maneuver units, while later on, as the generals got better and regiments smaller, entire brigades became the basic maneuver unit.  Belmont uses "battalions" (essentially half-regiments) for the Union, because that's how Grant maneuvered them, while at Shiloh and Gettysburg commanders maneuver brigades, because, again, that's how they were maneuvered historically. Fort Donelson, and all three battles in Across the Wide Missouri use regiments. Honey Springs uses battalions for the Federals, Regiments for the Five Indian Nations & CSA.

Troop strength varies a bit from unit to unit.  In brigade games a Combat Value (CV) point is @250-300 Confederate Present troops or @350-500 Union Present for Duty, Equipped, depending on how accurate I thought available troop counts were.  The base formula is 1 CV point for a "unit" plus CV points for strength (two 250 man units perform better than one 500 man unit). Then minus 1 for lack of arms or green troops or both, plus 1 for troops armed with breechloaders or repeaters or veterans.  (Trained, lightly blooded troops are "normal").  The end result is adjusted somewhat at the top end, as beyond a certain point, size conferred little advantage. No unit is allowed to go above a CV of 7 based on "hard" data when using the formula. On the other hand, I tried not to have 1 strength point infantry, so the range is 2 to 7 CV points. This range of strengths keeps the CRT working properly.

There ARE, however, a few 8 CV units in the games.  A unit like the Iron Brigade or the Stonewall Brigade, or Hood's Texas Brigade, acknowledged by both sides to be an elite unit, can be artificially promoted to CV 8, even when their numbers don't warrant it.  This is to encourage players to use famous and well led units as shock troops, as their historical counterparts did.

The Battles of the American Civil War Combat Results system makes large units less powerful than they look, because Losses are taken from the biggest units present in the combat. This works against elites, or large green regiments, which are formidible, but fragile. It is also a reminder that the Army reward for doing a dangerous job well is a more dangerous job.


Stacking represents coordination and control as much as physically packing the men tighter.  The average Union Army Corps could fit in a hex 400 yards across if anyone were idiotic enough to want to.  A "stack" is the rough maximum number of men who can be usefully vectored through an area during an hour's fighting.  In Battle of Gettysburg stacking is any 3 units or a Division's infantry, plus an artillery unit.  In Pea Ridge, a regimental game, stacking is 4 units or a Brigade and a battery.  In small battles, units spread out to protect or threaten flanks or take advantage of terrain. The time it takes a commander to receive and digest intelligence and respond means that a short front can be too easily flanked. Leaders of any sized army must extend their troops to give adequate warning of enemy threats and to slow him down while they respond. Since command reaction time is a function of line of sight, staff competence and officer skills more than numbers, the system seems to model battles of all sizes well.

Zones of Control (ZOC's)

ZOC's have become somewhat controversial.  I retain them, because at this scale either side's troops may not be exactly where the counter on the map indicates.  For one thing, nobody had maps of most of these fields until after the battle.  For another, there's always a gap between reality and "latest information". Also, real life doesn't have discrete phases, but a battle game that can be played in four hours practically has to.  So ZOC's mean the "other guys" have a counter-maneuver capability, too, and will probably be able to cover that gap before you can punch through. Micromanaging attack maneuver wasn't a realistic option in the Civil War.   Most ACW tactical attacks ended up being frontal assaults against a line.  ZOC's help keep it that way on the cardboard battlefield.  That brigade-sized stack is probably spread all over the 1200 yards it covers, but you don't know exactly where - you just have to trust your brigadiers, and the dice.


BACW Leaders come in two flavors: Army Commanders and Formation Leaders. Leaders are rated for "availability".  Almost half of what real commanders do during a battle is irrelevant to game leadership, so I account for that time commitment by making the Leaders "unavailable" to give attention to the fight during some turns (determined by die roll).  Unlike some games, this doesn't prevent units whose leaders are attending to another function from moving or fighting.  Some leaders (especially those who developed useful staff) keep their eye on the ball better than others, but even Gideon Pillow is better than no leader at all.

Formation Leaders (Brigadiers, Division Commanders, Corps Commanders, depending on the game) do lots of things, when they're available. They can:
• Coordinate maneuver, allowing good order troops to move at full speed.
• Rally Disordered infantry, returning them to full effeciveness.
• Direct construction of Hasty Works.
• Lead combat. Leaders shift the Combat Results Table 0, 1 or 2 columns, depending on the leader.  Gideon Pillow THINKS he's helping, but gives a negative shift. But there's only one Pillow. 

Formation Leaders may temporarily attach units from other formations, especially artillery, for particular combats. They're also the only ones who can properly maneuver Conscripts or Militia. Some leaders can coordinate massed Artillery into a Grand Battery for a powerful battlefield fire shock effect.

Officers may be lost in combat, and their replacements are invariably less effective, and take a while to come up to speed.  (Even a future excellent leader will perform below par when he takes command in the middle of a fight.) As the battle goes on, both armies will see their combat efficiency deteriorate.

Officers are the player's best chance to influence the battle.  A single Officer can influence Maneuver or Combat, but probably not both on the same Turn.  Deciding when to hold up your attack for an hour to organize the troops is a key choice you must often make. When Officers aren't available, a formation moves and fights somewhat more slowly and less effectively.

Army Commanders do pretty much whatever Formation Leaders can. They can also improve the chance that an individual Formation Leader will be available. However, Army Commanders aren't replaced during a battle, so before you let Lee's excellent Efficiency rating go to your head, think that through: finishing a battle with no Army Commander will significantly degrade your combat effectiveness. Put your Army Commander at his HQ and watch how much perkier the whole army acts. But sometimes, the place to be is right at the front. You decide.

Higher Formations

Higher "Formations" (Brigades, Divisions or Corps, depending on the game) become worn out due to losses or combat stress ("Fatigue"). Lose enough men and the whole Army will become Demoralized; although that doesn't happen in each game.  In multi-day battles you can do a limited amount of "reorganizing" formations which returns eliminated units to play. 

By end of a battle, a fresh combat formation in good order can turn the game around or clinch the victory, if you don't miscalculate and let your Army demoralize before that happens.  In the latter case a fresh formation may cover the retreat, inhibit pursuit and reduce the magnitude of your loss.  An army which expects to win must manage its formations so the right one (with the right leader) opens the battle, whole formations are available as reserve to complete the main attack, fend off an enemy initiative, or complete the victory, and secondary missions are assigned to forces appropriate to their missions. I'm pretty proud of the way the game generates realistic battle "narratives".  I hope you'll think so too. 

Combat Results

The Combat Results Table is superficially Odds based, from 1:3 or less through 5:1 or more. Odds can be shifted columns for Hasty Works, Cavalry vs. Disordered, Officer Efficiency and so forth, and the Table is slightly different if the battle is in "covered terrain".  Results are familiar: A Elim, A Retreat, Exchange, D Retreat, D Elim.  But the "Outcomes" of those are much less familiar. 

Outcomes can be Losses (affected side(s) lose the largest Unit involved), or Retreats.  If a retreat can't be accomplished it becomes a Loss, too.  Various individual situations change Outcomes: Artillery firing at Long Range is immune to loss unless the Defender can counterbattery; Units holding works ignore Retreat unless accompanied by Loss, Cavalry ignore most EX Losses (and so do their opponents).  So what KIND of combat it is affects what will happen.

The CRT is fairly bloody.  At either end of the CRT there are negative outcomes for the favored side.  Attackers never have less than 1/3 chance of loss and never have less than 1/6 chance of inflicting one. 

At the end of the day, Combat will depend on the troop mix, leadership and tactical considerations more than the size of forces. Piling on masses of units will possibly give a good outcome. However, what CERTAINLY will happen is a large chunk of your battle line will become disordered and vulnerable to counterattack, and what you MAY get from all that might be an exchange or an enemy retreat.


Infantry is the basic workhorse of Civil War battles. Unit for unit, infantry has more punch than cavalry, and retains more strength when disordered. Because much more infantry is available than anything else, infantry exchanges and losses don't degrade the army as much as losses of cavalry or artillery. Infantry formations can concentrate formidable amounts of combat strength in a single coordinated attack. In multi-day battles, infantry can reorganize and rebuild themselves to a limited extent. Discovering how to use infantry correctly is the basic game skill.


Cavalry is more, and less, than fast infantry. For one thing, cavalry strength varies by its state of Order.  Good Order cavalry is rated similarly to infantry, though slightly weaker due to the need for horseholders when dismounted and lower fire effectiveness when mounted. Disordered cavalry is about 1/3 weaker in strength than good order, but faster.  In a cavalry vs cavalry fight, holding out a good order reserve is very important.  And you may wish to voluntarily Disorder your horse to get them somewhere faster, accepting the reduction in combat value and cohesion.

Cavalry (and artillery) self-Rally. This makes maneuver while Disordered more attractive, and gives cavalry an obvious role in screening and probing missions where leaders aren't readily available. Mounted units are also less prone to engage in heavy combat - they're not as vulnerable, but they also won't push an attack to extremes. So their casualties will be lighter than infantry, but they probably won't inflict as many enemy losses.

Attacking Cavalry gains combat advantages against disordered troops of any sort, so it is possible to use massed horsemen as a battlefield maneuver force. Normally, however, infantry more than hold their own.


Artillery has two ratings, Close Combat (cannister, ball, short fuze shell) and Long Range Fire (mostly shell).  Smoothbores and Rifles have different ratios of Close Combat to LRF strengths.  A single gun in the regimental games typically has about 1 CV point, while in the brigade games a 4 gun battery is about 1 CV point.  Again varying by ammo weight.  Artillery quality is uniformly excellent for both sides, so doesn't vary the CV ratings. 

Artillery have a range of 3 when maneuvering, and can increase that range to 6 (or up to 9 for Rifles) by Surveying their position in. This isn't often useful in heavily wooded terrain, but at Gettysburg (and Antietam, when I get around to doing it) long ranged fire was critical, and commanders ought to at least consider planning to get the most out of the capability.

Artillery units are useful, in game terms, for several missions.

1) Artillery can disorder enemy attacks, and provide substantial close in defense if the attack does go in.

2) Artillery can isolate an engagement by engaging and disordering units to either side of the main combat. Since artillery firing at long range won't normally take losses, this is a useful economy of force measure.

3) Artillery firing in support of an attack can usefully increase combat odds to an individual attack. This works well for attacks by subordinate groups, since attached artillery may be able to upgrade CV significantly without requiring an officer to command the whole attack.

4) If a side has artillery superiority, whole enemy units may be lost to large scale bombardments. In conjunction with threat of a Grand battery a weaker enemy may be forced entirely out of a defensive position.

Good Order

The concept of Order is critical to the BACW system. Disorder occurs principally as a result of combat, though forced marching and moving through some terrain can also create Disorder. Infantry remain disordered until Rallied by a leader. Cavalry and Artillery are "self-Rallying" due to better group cohesion and leadership below the game's visible level, but do so instead of movement. Disordered forces forfeit ability to closely coordinate attacks. Disordered Cavalry lose strength but gain speed. Artillery may only fire at long range when in Good Order. Holding out fresh troops in Good Order and paying attention to Rallying disordered troops are key battle skills.

Army Trains

There is one Wagon counter per @100 wagons in the Brigade games or @20 in the Regimental games.  Their destruction is the same as losing a Combat unit, while capture is worth even more (nobody EVER had enough wagons).  Mainly they're a nuisance on the battlefield, but necessary to the Army. Keeping them safe is something each Army had to take the time to do.

A specialized Train is the Artillery Ammunition Reserve. When it is present, firing a heavy preparation with all your artillery is much more attractive. Not all armies and units had that kind of ammunition, or organization.


Each Army has a HQ unit, representing the command center of the Army. HQ's function in two ways:

1) they determine where an "unavailable" Army Commander can be placed when he becomes "available" again. Before HQ's were added to the game, Army Commanders were a little too able to dash all over the battlefield and personally direct things. Now they're still useful, but have to reconnect with the HQ every so often.

2) HQ's increase the Army Commander's "availability" slightly, and allow him to influence Formation Leader availability at a distance. That doesn't sound like much, but you'll come to appreciate a functioning HQ.

Cavalry HQ's are a variant that appear in Honey Springs and the forthcoming Battle Before Westport. Besides being significantly more mobile, they offer an interesting trade-off in that their escort troops are combat units in their own right. Bedford Forrest got a considerable amount of use out of his escort squadron, and you can, too, if you don't think you need the increased control HQ's can bring even more.


Early war armies made relatively little use of field fortifications, although permanent defenses feature all types. Still, units can construct "Hasty Works" whenever their Officers think it would be useful. Hasty Works change the tactical situation tremendously, largely because defenders can't easily be forced out of a position.

As Battles of the American Civil War get into 1864 and 1865 campaigns, troops will be able to construct Hasty Works on their own, and Officers can direct them to improve Works into Rifle Pits, and Rifle Pits into Entrenchments, to the joy of everyone.

PD Instance

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