Designer Notes for HPS’ Campaign Antietam

Hat tip to Rich Hamilton at his Gamesquad HPS Simulations blog for posting the Designer Notes for Campaign Antietam and another hat tip to Eddy Sterckx for pointing me in that direction. For those wondering what these games are all about, I have also posted the notes here. For those of you who do not know, the Designer Notes cover all aspects of creating the game, from the history of the campaign to orders of battle to maps. One of the first thing I’ll do when I open a new HPS game is to check these out. They never fail to please. The designer of Campaign Antietam is Rich Walker. Rich also designed Campaign Shiloh, Campaign Franklin, Campaign Atlanta, and Campaign Chickamauga. I just received the game in the mail this afternoon. Check back at TOCWOC over the next week or so for some screenshots.

Designer Notes for Campaign Antietam:

By: Richard Walker

Campaign Antietam follows my previous titles of Franklin, Shiloh, Atlanta, and Chickamauga. As such, it has been my first project (but not my last), to explore the Eastern Theater of Operations. It is certainly an honor to bring this most sacred battle, and those that preceded it, to the HPS ACW campaign series. Several years ago, I visited these battlefields. The impression I received cannot be put into words. These are indeed fields of honor that certainly deserve our attention.

Though not a part of the campaign feature for this simulation, the Battle of 1st Bull Run (Manassas) has been included to serve as a backdrop to the comflict yet to come. During this crucial first battle, the realization that this civil war would be bloody and long, began to sink in. It was also here that the nickname Stonewall was given to Confederate General Thomas Jackson.

Campaign Antietam seeks to recreate the crucial battles that concluded with America’s bloodiest day. The first battle to be represented in this campaign is Cedar Mountain. A relatively small battle, but certainly a telling prelude of what was to come. Following are the increasingly intensive battles of Groveton (Brawner’s Farm), 2nd Bull Run (Manassas), Chantilly (Ox Hill), South Mountain, and finally Antietam (Sharpsburg). Several variants are included that further expand the historical possibilities. These variants include a large battle near Hagerstown, and an entirely separate campaign file that incorporates one of the new features included with this release, the random reinforcements, time and location upgrade. This feature will make it so every new game will be different. No need for endless variants. One game will provide the needed variation. Neither side will have full knowledge of the time and location of new troops entering the battlefield.

As always, my objective in designing these games is to provide historical accuracy, tactical experience, and most of all, FUN!

Project Research

Like all my previous titles Campaign Antietam has been heavily researched to ensure that the extraordinarily high standards introduced in other John Tiller games are continued. By far, the greatest resource available to any Civil War enthusiasts, whether he be an historian, museum curator, or game designer, is The War of Rebellion: Official Records of the Union and Confederate Armies.* This set of research books is more commonly referred to as simply, the O.R. Fortunately for myself, the O.R. has been reproduced onto a CD. By typing in a few key words, much information can be obtained in a relatively short period of time.

But as any good historian knows, relying on a single source for information is a grave mistake. So I utilized a great many other sources, both primary and secondary. Probably the most valuable primary source are the battlefields themselves. A visit to the battlefields can give great insight. Walking upon the same field that was fiercely contested over 140 years ago is certainly an enlightening experience . For example, Antietam and Bull Run are very well preserved battlefields that gave me much to think about as I stood near the the site known as the Sunken Road, or the Cornfield. I encourage you to visit these historic parks.

Much has been written about the various battles covered in Campaign Antietam. Here are just a few of the many sources used to research this project.

The Official Military Atlas of the Civil War, Major G.B. Davis*

A Compendium of the War of the Rebellion by Frederick H. Dyer

Battles and Leaders of the Civil War, Vols one and two. Printed by Castle*

Landscape turned Read: The Battle of Antietam, by Stephen W. Sears

Return to Bull Run: The Campaign and Battle of Second Manassas, by John J. Hennessy

Antietam: The Soldiers Battle, John Michael Priest

Lee takes Command, The Civil War Time Life Series Books

First Blood, The Civil War Time Life Series Books

The Bloodiest Day, The Civil War Time Life Series Books

The Gleam of Bayonets, by James V. Murfin

We Shall Meet Again, by JoAnna M. McDonald

Second Manassas to Pocotaligio, by Shelby Foot

The Official Atlas of the Civil War, New York 1958

Lincoln and his Generals, Harry T. Williams

U.S.G.S. Topographic Quadrangle Sheets

And many more…

*-primary sources

The Order of Battle(s)

One of the most important aspects of any endeavor of this kind is creating an historical Order of Battle, or OOB. If you are the grognard type and print off these OOBs, you may be a bit confused. Every effort has been taken to ensure that each OOB is as historically correct as possible. However, I will explain where you might see some differences. First, in order to create the many variants that exist with Campaign Antietam, the historical OOBs were altered in order to include units that did not historically take part in the battle.

In terms of research, great effort has been made to ensure an OOB that is historically accurate. But caution must be used, along with even a little guess work. It is very important not to trust any single source when compiling an OOB. Rarely will two completely agree with each other. Often times, several sources must be combined to achieve a desired result.

The most complicated part of creating an OOB is distributing troop strengths. The Official Records give actual abstracts, sometimes on a weekly basis, that inform on these strengths. The tricky part can be multi-folded. It often happens that a regimental commander’s O.R. report will differ from the brigade commander’s report in terms of troops present. In such cases I almost always will choose the regimental commanders report as the most accurate. Unfortunately, it too often occurs that NO report is given. In these cases, it may happen that you take the nearest available report and divide as needed. For example: let’s say that a brigade commander does mention the number of troops participating in a given battle, but only two of the five regimental commanders have submitted their reports for publication. In this case, I would take the brigade commanders total number and subtract out the given regimental reports. So if three regiments’ strengths were left unreported, I would simply distribute the remaining trop s to the other regiments as an average with a five percent variance.

In Campaign Antietam, I have created several OOBs and variants. Artillery and cavalry have been designed in such a way that each unit can be deployed as a single unit, or subdivided. For artillery, two gun sections are possible. For cavalry, squads are available for deployment. So instead of having one 500 man unit, five 100 man units will be available.


I have had the great privilege to work with and have on my playtesting team many talented individuals that love these games and want them to be the very best they can be. As a result of their efforts, nearly every scenario has been thoroughly tested and tweaked to ensure a reasonable balance. It is always the case that both sides MUST have the possibility for victory. If one side has zero chance to win, then the game is flawed. However, some scenarios will certainly require a very skilled player for victory. But I am certain that enough variants exist for any given situation. And don’t forget the game editor and optional rules provided by John’s programming skills. If you find that a game needs a few more tweaks to meet your needs, the tools are there for you, go for it!

In short, I am extremely proud of my team and it has been an honor to work with them. They are as follows:

Aleksander Krolikowski

Rich Hamilton

John Ferry

Lee Hook

Doug Strickler

Rich White

Ernie Sands

Scenario Design

For Campaign Antietam, I have designed many scenarios that give players a high degree of choice. I have scenarios that use a straight forward design method (no weather, or special units). In addition, most scenarios have been designed to use the new weather feature introduced with Campaign Atlanta. This feature has been tweaked with lessons learned. There are many scenarios that have been specifically designed for solo play against the A/I. Others have been altered to use sectional artillery, instead of whole batteries. Also, there are many scenarios that are considered meeting engagements. And much more. When deciding on which scenario to play, be sure to read the provided descriptions in the main program.

Artificial Intelligence (A/I)

Nearly all war games give the player an option to play against the AI. And nearly all fall far short of being considered real competition. Unlike chess, which has a limited and well defined playing field with limited and well defined units, in complex war games such as this one it is difficult to achieve an artificial intelligence that will be both challenging and unpredictable. John Tiller has programmed into this game a system that allows the AI to be either scripted or use a self-move dynamic A/I. A scripted AI refers to a system that allows a human designer to map out each units movements up to the point that enemy contact is made. You can script a unit to go from point A to point B at a certain time and on a certain date. If enemy contact is made, the AI will still try to make point B, but will engage the enemy until a pathway is clear for continued movement.

The designer can tell units to be in attack mode or defense mode. These different modes will affect how the units approach their destinations. You can read about how scripting is accomplished by reading the scenario editor help notes. Another form of AI is the dynamic method. Using this system, the designer does not need to script any units. Rather a simple number system tells the AI what kind of strategy it will need to adopt. Will it be offensive or defensive, extreme or normal? Of the two mentioned AI systems, the scripted system will in most cases provide the most challenging scenario to the human opponent. The trick is anticipating future enemy movements. In most cases, this is more difficult than it sounds. However, it must be stated that some scenarios will have one side or the other that is easier to script and therefore should be more challenging if played against that side. Put simply, it is easier to script a strong attack then trying to anticipate an attack and make the proper scripting for a strong defense. Some scenarios will state this fact in their descriptions. AI has come along way, but in the end, the best game will be played against a competent human opponent.

Strategy Tips

Campaign Antietam is unique in a number of ways. As I previously mentioned, this new game introduces new features that will change the way you may have previously played. No longer will you be able to move, fire, melee, then move, fire and melee again. Now, with the use of the new “Optional Melee Resolution” rule, you will be held to a more closely held historical method of attack. Move, fire and melee. That’s it! Our former blitzkrieg tactics will finally have to wait until 1939.

As with all HPS Civil War titles, one important fact that must always be remembered is the notion that this is a campaign, and not a series of stand alone battles (however, each battle may be fought as a stand alone battle without attempting the campaign). After each battle, your loses will carry over to the next phase of the campaign. So, a well fought campaign can find General Lee or McClellan in a much weaker state then was the historical reality. Imagine a brilliant Confederate victory early in the campaign with much higher Union loses and lower Confederate loses. In such a situation, a Confederate victory at Antietam may yet become a southern dream come true.

So as a Confederate commander, conserve your strength and especially your cavalry. Your cavalry can make or break you. Don’t send them head long into a copy cat of Marshal Ney’s unsupported cavalry charge. Use them as hit and run flankers. Never, if possible, dismount them. They’re not intended to fight as infantry after all! If you can time your attack carefully and get in the enemies rear or flank, a melee will almost always result in massive casualties for your foes. But be mindful of the fact that there may be enemy cavalry lurking not far away. What you can do to them can be done to you. Before making an attack, calculate the possibility of the enemy making an effective counter-attack. If your cavalry fails to last the entire length of the campaign, your campaign will fail.

Artillery can also be an important weapon, if used correctly. But be careful. You only have a limited number of cannon, and once gone, they’re gone forever. Artillery will only rarely make successful long range shots. So be mindful of your artillery placements and victory points lost if destroyed or captured. But for those that enjoy artillery duels, Campaign Antietam offers numerous battlefield situations that give ample opportunity for lots of artillery fire.

Playing the game

Though this game comes with a two player hot seat, LAN play, and an artificial intelligence, with the ability to play as either side in solitaire mode, I have found that the most enjoyable way to experience a challenging game is to play by email, known simply as PBEM. This form of play is both fun and simple. PBEM allows for many advantages. First, play as your schedule permits. No need to rush. If you’re playing a complicated scenario where much time and thought is needed, but dinner, work, or family is about to require your attention, just save and continue at a later time. Also, encryption allows both players to play knowing that their forces cannot be spied upon by “accident.” It’s even possible to play with more than 2 players.

Worried about finding opponents? No need to be concerned. There are many sites that can be visited that will gladly provide players willing to cross swords with you. Two of my favorites are the ACWGC (American Civil War Game Club) and the Gamesquad sites.



Just copy and paste the above sites to your URL address line, and your PBEM adventure will just be moments away.

Using this method of play will provide you with many hours of enjoyment. Game with players all around the world. One of my playtesters (Aleksander Krolikowski), whom I’ve found to be an excellent source for historical accuracy, lives in Poland and has never visited an American Civil War battlefield. So if you live in Virginia or Maryland, and know these battles like the back of your hand, don’t be surprised when someone halfway around the world smacks you down with impunity.

In addition, these sites have very active forums that provide playing tips, and suggestions for future titles. And if you’re unhappy with some of the graphics and scenarios provided with the original release, not to worry, these sites and others will further enhance your experience with alternatives.

So if you want my advice, try PBEM. You won’t be disappointed.

New Features for Campaign Antietam

1) Optional Melee Resolution: Tired of blitzkrieg type tactics? This feature will not allow melee until the completion of movement and fire. So dislodging a unit in order to melee another unit, will no longer be possible. This feature creates (in my opinion) greater historical accuracy. Players will need to better coordinate their battles. This feature will also reduce the higher than historical loses to a more acceptable level.

2) Artillery Ammo by Cannon: If this option is chosen, each cannon tube firing will expend one ammo point. The program will recalculate the number of ammo points from the original pool supplied by the designer.

3) Random hex and time for incoming reinforcements: This new feature will allow each game with oncoming reinforcements to be unique each time it’s played. In short, reinforcements will have three characteristics. First, percent for arrival times. Second, arrival hex. Third, percent for each arrival hex. When all three of these characteristics are used, neither player will know where or when new troops will arrive. Imagine, each game being unique. No more need for endless variants.


With the exception of Cedar Mountain, Chantilly, the eastern portion of South Mountain, and some touch ups, all the maps used in Campaign Antietam, were designed by Doug Strickler. Doug is the designer for Campaign Gettysburg. The following are Doug’s comments taken from his map notes supplied with Campaign Gettysburg.

Design philosophy:

I consciously began development with a desire to go big in regard to the maps involved. I lobbied John on this matter, and received his blessing and substantial assistance with the tools needed to accomplish this task. While the big maps bring with them problems for some gamers – too much maneuver being the biggest complaint, I think the upside outweighs this and similar concerns. Additionally, one can always generate sub-maps and avoid the problem entirely – I’ve done so for some of the smaller scenarios, and some stand alone battles.

I also wanted to make the maps aid in restricting certain “gamey” aspects of play. Fields of view were limited/broken up where possible consistent with the terrain. Movement was restricted – again where possible consistent with the actual terrain. In short I did what I could to encourage the player not to use his forces as if they were some 19th century version of a panzer division. While other aspects of the game system have a greater effect in this regard than do the maps, I did what I could with them to try and contribute to restricting what I regard as ahistorical play.

It should be noted that I didn’t regard this as a “Gettysburg” game. The battle has been done, and done again. This is a game of the Confederate summer offensive of 1863 in the east. From a map making standpoint this means that, while I tried to get the Gettysburg battlefield as true to life as possible, I didn’t regard it as any more important than the other areas covered. I approached this entire project with the full knowledge that there are many people who know more about this battle and campaign than I. This holds true for the terrain as much as for any other aspect of the campaign. I’ve done my best in this regard, and – of course – welcome any constructive criticism.


Topographic and hydrographic data were generated first, working from the USGS 7.5′ quadrangles. In most instances I had a high degree of confidence that these features had not changed dramatically in the intervening time. In those relatively rare occasions that I was clued as to major changes in these features, they were modified based on contemporary sources. In entering the topographic features, I over emphasized terrain changes if anything, creating blind spots, and points of observation. By overemphasize I mean that, e.g. a rise which might not warrant depicting as a full hex based on the physical space it occupies was often depicted as a full hex. I do not mean that I added features that were not present. Similarly, I also over emphasized hydrographic features, creating streams even where the USGS data indicated they were of an intermittent nature. I made this decision for two reasons: (1) portraying the hydrography in this fashion helps break up the map – it looks better, and (2) it reflects the effect of stream beds on movement which, in my opinion, exists regardless of the presence of water in the beds.

Rail lines were entered as they currently exist for railroads that were extant at the time of the conflict. I initially felt that it was unlikely that their location had changed to any great degree in the intervening years – an assumption that was largely borne out upon review of the contemporary sources.

I then conducted an examination and cross referencing of the contemporary sources and developed a consensus as to the location and nature of the road net, and entered the data for it. I found that the road net corresponded to a surprising degree with today’s roads. While I had anticipated this association for the rail net, the degree of agreement between the road net of the 1860’s and that of today came as somewhat of a shock to me.

A similar technique was employed to identify and enter place names and houses. The Virginia county maps generated by the Confederate engineers were of particular assistance in this regard, as were the pre-war county maps of Maryland and Pennsylvania. The latter were commercially produced by several companies, and were all compiled within a few years immediately prior to the war.

Vegetation was the final item entered, and was the most problematic. Other than for areas in which pitched battles were fought, there was scant information for much of the area covered by the maps. Again, in some instances, I used the maps of the Confederate engineers to fill in this information. Some of the maps from the Official Records and other sources also contained sporadic detail in this regard.

Written descriptions of terrain were consulted, but, for the vast majority of the territory depicted in the maps, there was not enough detail to add to what I could otherwise glean.


The degree of agreement between the current road net and that of the 1860’s mentioned earlier was the single most interesting finding of the map construction. The Confederate engineer maps proved invaluable in accurately depicting the road net and place names. In general they proved to be very on target – not surprising given the greater familiarity with the territory that one would anticipate the southern engineers having.

The single aspect of current maps which was least helpful is the forestation. In those instances in which I could get access to maps from the 1860’s which depicted forestation there was generally less cover than there is at present. It sounds at first blush counterintuitive, but, upon further reflection, the shift from an agrarian society heated by wood to the current state of affairs supplies ample explanation for this phenomenon.


Surprisingly, given that the eastern theater was undoubtedly the most extensively mapped of the war, the map making was hard. This was so in part because there are so many sources. Here’s the problem: few of the sources agree with each other. This holds true for the road net, place names, locations of fords, forestation – in short virtually every aspect of the map making. This lack of agreement led to many a false start in rendering what I needed to depict, and, undoubtedly, to mistakes in what is depicted.

While many sources exist, obtaining access to them was a time consuming and, at times, exceedingly frustrating experience. Many of the sources available on line were not scanned at sufficient detail to be usable in any but the broadest of fashions. Others were of sufficient detail, but required considerable work to get in a condition I could use. On the plus side, they are available. Far more are available now, than at the time I started this project – which also happened to be the time I did most of my map work. The increased availability of maps over the past few years has led to my returning to the maps time and again during the course of the development of the game. I can’t begin to tell you how often they have been revised.

Most of the maps revolve around a 3 by 3 set of USGS quadrants that became my standard format. I felt this gave sufficient room to allow the maneuver in the games that I wanted to incorporate. This meant dealing with .bmp files of close to 100 Meg in size. 512 Meg of RAM is barely adequate for this task. To do it again, I’d upgrade to 1 Gig which would speed up the process considerably.

Final Comments

I would like to thank John Tiller for allowing me this opportunity to work on and design Campaign Antietam. These games are certainly the best on the market if you’re interested in true historical simulations. In the 6 years since HPS and John Tiller first introduced the ACW campaign series, I have yet to see another company come out with a more accurate game that recreates the flavor of Civil War tactics on the regimental level. And the journey is not yet over. More titles are in the making, and more tweaks to the engine will soon be introduced that will continue to enhance these games. Please feel free to offer your comments. It’s you, the buyer and player that provide most of the ideas for game improvements. Thank you for buying and playing Campaign Antietam. Remember rule number one, HAVE FUN!


3 responses to “Designer Notes for HPS’ Campaign Antietam”

  1. Doug Avatar

    I have the old TalonSoft Antietam and Bull Run so probably will not purchase this new version.

    If you are searching for another Eastern theater, consider the Shenandoah Valley Campaigns. I am surprised that this theater has not been covered.

    There could be scenarios / campaigns:
    – 1861 Patterson keeping Johnston occupied before Bull Run I;
    – 1862 – Jackson and Ewell v Banks and Fremont;
    – 1863 – Milroy v Ewell;
    – 1864 – Sigel, Hunter, Wallace and Sheridan v Breckenridge, Jones and Early.

    There may be interest in the West Virginia theater in 1861 – McClellan and Rosecrans v Floyd and Lee.

  2. Bob Wenstrup Avatar
    Bob Wenstrup

    I enjoy these games alot…
    is there any chance of improved graphics along the line of the original Battleground series? Really enjoyed those!

  3. admin Avatar


    I don’t think HPS has any plans to upgrade the graphics any time soon. At least I haven’t heard anything. Who knows though. They are running out of campaigns to do using this game engine, so John Tiller might design a next generation game engine one of these years.


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