Category Archives: Game Design

A Game of Birds & Wolves

Commander Roberts going over the lessons learned from “The Game.” Photo from, “A Game of Birds and Wolves,” by Simon Parkin.

Simon Parkin’s A Game of Birds and Wolves: The Ingenious Young Women Whose Secret Board Game Helped Win World War II, tells the fascinating story of a wargame created during the height of the U-Boat Atlantic campaign to be used as a testbed for discovering new anti-submarine tactics. In early 1941, when German wolf packs were destroying Allied shipping at a devastating rate, British Naval Commander Gilbert Roberts was taken out of retirement and personally ordered by Winston Churchill to, “Find out what is happening and sink the U-boats.”

Roberts was given the top floor of the Western Approaches HQ in Liverpool and a small group of WRENs (Women’s Royal Naval Service) as assistants to invent tactics that would counter the enemy wolf packs. His project would be called the Western Approaches Tactical Unit (WATU). (The Western Approaches HQ in Liverpool is now a museum and I can’t wait to visit it when this pandemic is over and General Staff is finished.)

The WATU project – known simply as, “The Game,” – is not the first example of a wargame used as a testbed to discover and improve combat maneuvers. Indeed, Scotsman John Clerk, wrote, An Essay on Naval Tactics: Systematical and Historical in 1779 after using, “…a small number of models of ships which, when disposed in proper arrangement, gave most correct representations of battle fleets… and being easily moved and put into any relative position required, and thus permanently seen and well considered, every possible idea of a naval system could be discussed without the possibility of any dispute.” Using these models Clerk proposed the tactic of “cutting the line,” that Nelson employed at Trafalgar¹⁾https://en.wikipedia.org/wiki/John_Clerk_of_Eldin. Nelson would quote from Clerk’s essay in his famous Trafalgar Memorandum.

When Roberts reported to Sir Percy Noble, commander of Western Approaches he explained that he intended to, “develop a game that would enable the British to understand why the U-boats were proving so successful in sea battles and facilitate the development of counter-tactics… The game would become the basis for a school, where those fighting at sea could be taught the tactics. With a few adjustments.. [the] wargame could be used for either analysis or training.”²⁾A Game of Birds and Wolves, p. 143 Not surprisingly, Roberts was met with skepticism and not a little bit of derision. As one who is constantly pitching the importance of wargames to the U. S. military I understand the uphill fight that Roberts was facing. British destroyer commanders definitely did not want to go to Liverpool to, “play a game.” But, since the orders had come directly from Churchill, Noble had little choice but to give Roberts the top floor of the Western Approaches HQ for his ‘game’. Roberts made a tactical mistake by referring to WATU’s ‘product’ (in modern bureaucratic parlance) as a ‘game’. I learned this early on in my career: never say the word ‘game’ if it can be avoided. Call what you’re working on a ‘simulation’. Chess is a game. Risk is a game. But I write simulations; and clearly what Roberts was working on was a simulation, too. (That said, the phrase, “game it out,” has now passed into the common idiom and is synonymous with ‘simulation’.)

WATU simulated Fog of War by requiring the users to view the board through peep holes cut in canvas drapes. Submarine tracks (see above) were drawn in green chalk which, apparently, was not visible from the other side of the canvas sheets. The photo shows British destroyer commanders playing, “The Game,” and learning from the simulation. Photo from, “A Game of Birds and Wolves.”

In order to simulate Fog of War Roberts invented a system in which the destroyer commanders would view the board from behind a canvas sheet; their view of the battle restricted by peep holes cut in the canvas. Furthermore, submarine tracks were drawn with green chalk on the floor (see above photo) which, somehow, became invisible when viewed from the other side of the canvas. Consequently, the destroyer commanders had only a restricted view of the battle around them and were completely in the dark as to the simulated U-boats positions.

When Roberts began his work nobody in the British Admiralty knew U-boat tactics. Indeed, the German U-boat commanders were creating their tactics on the fly often ignoring the Kriegsmarine’s Memorandum for Submarine Commanders to fire torpedoes at no closer than 1,000 meters. U-boat ace, Otto Kretschmer was the first to insist that the most efficient way to attack convoys was to slip inside the destroyer screen, launch torpedoes at a range of about 500 meters, submerge and wait for the convoy to pass over them to make his escape ‘out the back’ of the convoy. Interestingly, this was the same technique that I discovered playing Sierra On Line’s Aces of the Deep.

One of the first scenarios that Roberts investigated using his new wargame was the battle of Convoy HG 76. This was a multi-day contest involving 32 merchant ships, 24 escorts and 12 U-boats. It was considered a great Allied victory because five U-boats were sank (though the Allies only knew of three at the time) and 30 merchant ships made it home safely. Assisted by WRENs Jean Laidlaw and Janet Okell, they replayed the historical situation hoping to understand Allied commander Captain Frederick John “Johnnie” Walker’s anti-submarine maneuver ‘Buttercup’. The Buttercup maneuver (named after Walker’s pet name for his wife) involved, “on the order Buttercup… all of the escort ships would turn outward from the convoy. They would accelerate to full speed while letting loose star shells. If a U-boat was sighted, Walker would then mount a dogged pursuit, often ordering up to six of the nine ships in his [escort] group to stay with the vessel until it was destroyed.”³⁾A Game of Birds and Wolves, p. 155

What confused Roberts was that the Allied merchant Annavore was torpedoed while in the center of the convoy. As he and the WRENs replayed the scenario they could not duplicate reality unless the U-boat had, “entered the columns of the convoy from behind. And it must have done so on the surface, where it was able to travel at a faster speed than the ships. By approaching from astern, where the lookouts rarely checked, the U-boat would be able to slip inside the convoy undetected, fire at close range, then submerge in order to get away.”⁴⁾The Game off Birds and Wolves. P. 158

Using the scenario of when the escorts actually sank a U-boat using the Buttercup maneuver it was determined that they had succeeded by only accidentally hitting a U-boat that was joining the attack on the convoy and not the actual U-boat who had made the attack that they were pursuing. This makes sense when you realize that the attacking U-boat had submerged immediately after the attack and was waiting for the remaining convoy to pass overhead while the escorts were running far outside the perimeter of the convoy looking for it.

In other words, Walker’s Buttercup maneuver was, in fact, a terrible anti-submarine tactic.

The ‘Raspberry Maneuver’, created from numerous runs of ‘The Game’ was determined to an effective anti-submarine tactic. Here it is drawn by Admiral Usborne. From the book, “A Game of Birds and Wolves.” Click to enlarge.

The first successful anti-submarine tactic to be invented using the Game as a test bed was, “Raspberry,” (so called by Wren Ladlaw as a ‘raspberry‘ to Hitler). As you can see from the above drawing, upon discovery of a U-boat or a torpedo hit, the escorts draw closer to the convoy, not the opposite as in Walker’s Buttercup maneuver. When Roberts and the WRENs ran a scenario for Western Approaches commander Noble and his staff, Noble – who at first was highly skeptical – was so impressed that he immediately sent a message to Churchill, “The first investigations have shown a cardinal error in anti-U-boat tactics. A new, immediate and concerted counter-attack will be signaled to the fleet within twenty-four hours.” ⁵⁾The Game of Birds and Wolves, p. 162 By summer of 1942, using these new maneuvers, U-boat losses had quadrupled. Eventually other anti-U-boat maneuvers were also developed by the WATU team and all Atlantic destroyer commanders were ordered to WATU to play, “The Game,” and learn the lessons.

Obviously, there were other improvements in anti-submarine warfare that also contributed to the Allies winning the Battle of the North Atlantic. Nonetheless, it is interesting to read about the proper application of simulations in wartime. I have long been an advocate of simulations to test, “what if” scenarios. Indeed, this has been the main focus of my professional career for thirty plus years. It’s still an uphill battle.

References[+]

References
↑1	https://en.wikipedia.org/wiki/John_Clerk_of_Eldin
↑2	A Game of Birds and Wolves, p. 143
↑3	A Game of Birds and Wolves, p. 155
↑4	The Game off Birds and Wolves. P. 158
↑5	The Game of Birds and Wolves, p. 162

The State of the Game

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Grant’s Overland campaign that began at the Wilderness and ended at Petersburg. It can be argued that Grant did not win one battle but, clearly, achieved a great strategic victory. This was the beginning of the end for Lee’s Army of Northern Virginia and the beginning of the end of the American Civil War. Map by Hal Jespersen (www.posix.com/CW), found on Wikipedia. Click to enlarge.

I had just sat down to write this blog when a derecho,¹⁾Ironically, the first person to use the Spanish word “derecho” to describe this type of storm was Gustavus D. Hinrichs, a German immigrant who settled in my hometown of Davenport in 1861. with wind speeds that peaked at 117 mph, flattened much of Iowa and dropped a hundred year old maple tree on my ’98 mustang. We also lost power and internet for a week. I spent much of that time reading old favorites including Horace Porter’s Campaigning with Grant. Porter, who served on Grant’s staff during 1864-5, provides a first person account of many extraordinary events from the start of the Overland Campaign to Lee’s surrender at Appomattox. Admittedly, the 19th century prose does get a bit flowery at times, but the he was actually there when it happened aspect of this memoir makes it invaluable.

I was struck by this passage from the beginning of the campaign and how it felt like what I wanted to write about to explain where we are on completing General Staff:

“[Grant] said,… “The only time I ever feel impatient is when I give an order for an important movement of troops in the presence of the enemy, and am waiting for them to reach their destination. Then the minutes seem like hours.” – Campaigning with Grant

At this point Grant was now General in Chief, commander of all U. S. armies including the Army of the Potomac. Orders had been issued and every U. S. army was to be on the march at this very moment and there was nothing more that Grant could do. Grant was confident that his plan would ultimately be successful. If we look at the map of the Overland campaign (above) we see that Grant wanted to fight Lee in the open. If that was not possible he would move by his left and Lee would have to respond. Eventually, Lee would be forced to entrench around Richmond and Petersburg and Grant would trap him. It was like a chess master looking sixteen plies ahead: there was nothing Lee could do, his defeat was inevitable.

There are two programmers coding General Staff: Andy O’Neill is working on the actual game from my design documents and me (I’m working on AI). Andy specializes in Microsoft Windows Presentation Foundation (WPF) development of business applications. General Staff is a wargaming system that utilizes multiple interlocking programs (like Microsoft Office) so it is logical to use Microsoft WPF for development. Andy is literally a Microsoft gold medal developer. Andy also specializes in the Model-View-View Model (MVVM) development technique. This is a method commonly used in Microsoft business applications. Despite repeated efforts to learn MVVM I confess that I am just an old coder, set in my ways, and I can’t get it. While Andy and I both write in the C# programming language, it’s best if I do not muck about with Andy’s code. What I do is write AI routines in C# and Andy imports them into his code.

In early July or late June Andy, who lives and works in Liverpool, England, fell very ill with an undefined infection. He became very dizzy and nauseous and was unable to write any code for over a month. Andy reports that he is now, “sort of…nearly…better.”

And this is why I felt like Grant on May 2, 1865: there wasn’t anything I can do to move the game forward. I’m working on the AI Engine and researching battles, maps and OOBs but that’s it. And then we lost power and the internet for a week.

My wife says that when I can’t work I get, “very testy.” Grant, however, outwardly was imperturbed. This is how Porter describes him this day:

General Grant Whittling Again – Civil War Reenactor Kenneth Serfass portraying Lt. General Ulysses S. Grant whittling at the site of Grant’s headquarters knoll at the Battle of the Wilderness. 150th Anniversary of the Battle of the Wilderness, 1864-2014

“… most of the day he sat upon the stump of a tree, or on the ground, with his back leaning against a tree. The thread gloves²⁾It is assumed that Mrs. Grant gave him the gloves. Grant wore them out whittling and never wore them again. remained on his hands, a lighted cigar was in his mouth almost constantly, and his penknife was kept in active use whittling sticks. He would pick up one small twig after another, and sometimes holding the small end away from him would rapidly shave it down to a point, at other times he would turn the point toward him and work on it as if sharpening a lead-pencil, then he would girdle it, cut it in two, throw it away, and begin on another.” – Campaigning with Grant

So, in summation, almost nothing has been done in the last six weeks to move development of the actual game (what we call the Game Engine application) forward. For this I can only sincerely apologize and repeat what you know: there’s only two of us coding it and when the lead coder falls ill everything stops.

What’s Going on with the Scenario Editor?

There are three stand alone programs that create data files used by the General Staff Game Engine: The Army Editor, the Map Editor and the Scenario Editor. The first two have long been available to early backers. What’s holding up the release of the Scenario Editor?

The Scenario Editor is actually done, and has been completed for some time. I use it to create the scenarios that you’ve seen and that I use to test the AI:

Screen shot of Antietam with battle groups, range of influence and objectives displayed. Click to enlarge.

So, why haven’t we released it? Because as we (that is to say, Andy) works on the Game Engine we discover that we need to make changes in the data files. For example, I left out the time it takes for a unit to change formations. To correct this, we need to add that value to the scenario data files and that, in turn, means a change to the Scenario Editor, itself. And, even worse, it means that previously created scenario files are no longer compatible and have to be redone. Andy, specifically, said he didn’t want to make the Scenario Editor available to early backers for this very reason: you could lose your earlier work.

So, in conclusion, again please allow me to apologize for these delays. There will inevitably be more delays before General Staff is completed. But, like Grant at the beginning of the Overland campaign, I am supremely confident in our inevitable success. Grant famously said at this time, “I propose to fight it out on this line if it takes all summer.” It actually took all summer, fall, winter and next spring before Lee surrendered. But the ultimate success of the campaign was never in doubt.

And, as always, please feel free to email me directly at Ezra [at] RiverviewAI.com.

References[+]

References
↑1	Ironically, the first person to use the Spanish word “derecho” to describe this type of storm was Gustavus D. Hinrichs, a German immigrant who settled in my hometown of Davenport in 1861.
↑2	It is assumed that Mrs. Grant gave him the gloves. Grant wore them out whittling and never wore them again.

Ty Bomba’s Primer on Strategy & Tactics

Movement & Maps

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Screen shot showing unit movement arrows for the battle of Antietam scenario. Note how movement is stopped by the small creek in the upper left hand corner of the screen. Click to enlarge.

I‘m in self-quarantine. As many of you know, I had a bone marrow / stem cell transplant in 2014 followed by a year of intense chemo. I’m fine (all things considering) but my immune system took a beating. In 2014 H1N1 put me in the hospital for 3 days so I’m taking COVID-19 seriously as, uh, the plague. In a way, being cooped up in the house (the weather hasn’t been cooperating, either, as I had hoped to replace my daily gym workout with long walks with my dog, George) is a lot like a typical upper Midwestern winter: it’s what I call ‘good programming weather’. There’s not much else to do but hunker down and write code. So, obviously, I’m working on General Staff and I wanted to show you an update (above).

General Staff is being written in C# and Windows Programming Foundation (WPF). There are a number of technical reasons why this was a good idea but I’m not overly familiar with WPF and doing some basic things, like creating these transparent movement arrows, took far longer, and involved a lot more programming, than I thought it would. My partner on this project, Andy O’Neill, is a WPF rockstar; I’m a novice. I would much rather be working on the ‘under the hood’ stuff (like AI) but for the last week or so I’ve been working on movement arrows while Andy is busy with another project (the kind that pays the rent). Anyway, I’m very pleased about how they turned out. Please feel free to write me with comments.

Movement arrows for units at Quatre Bras. Note how blue units are stopped by the stream feeding the large pond. Click to enlarge.

Forward movement of this blue division is stopped by this tiny creek.

But, I also discovered a very interesting problem while testing these movement routines: our maps are too good! If you look at this detail (right) from the Antietam screen capture (above), you’ll see that movement is stopped when it encounters a tiny creek. I’ve walked that area of the Antietam battlefield and that little creek (well, I think it would be more properly called a ‘crick’) wouldn’t stop a division moving forward. However, the movement validation routines stop units from crossing bodies of water (except in column formation while crossing a bridge or a ford). Ed Kuhrt, who digitized these great maps and copied every small detail was, perhaps, too precise. Definitely better to err on the side of being too precise when it comes to maps, Ed.

We’re seeing the same thing at Quatre Bras (above): the little streams that feed Materne Pond (Etang Materne) are also stopping the French from attacking. I haven’t been to Quatre Bras but I know the French crossed the small streams to attack the Anglo-Allied army’s positions.

Luckily, fixing this is easy. If you have done any work with the General Staff Map Editor you know that erasing terrain features, like water, is quick.

Removing the water in the little stream that feeds Antietam Creek by placing a ‘field’ over the water. Note that the ‘Field’ object is ‘above’ the ‘River’ object on the left Edit Terrain tab. Screen shot. Click to enlarge.

In the above screen shot we’ve opened the Antietam map in the General Staff Map Editor and drawn a ‘Field’ over the ‘crick’ that kept the Union forces from advancing. Note that both the Field and the River are objects and whichever object is higher in the list on the left ‘overwrites’ lower objects. If, for whatever reason, we wanted to restore the water in the creek we could either delete the Field or move it lower down the list than the River object.

Edit: After originally posting this, some readers (see comments, below) suggested that units crossing a small stream should suffer a movement penalty. This is absolutely correct. Instead of ‘painting’ with ‘field’ terrain, I should have used ‘mud’. This allows for a movement penalty (set in the Scenario Editor).

Adjusting unit type speeds across various terrain types in the General Staff Scenario Editor. Screen capture.

And now that that obstacle to movement has been eliminated the I and XII Union Corps can advance:

Now that the water has been removed from the little stream feeding Antietam Creek the Union forces can advance again. Screen shot.

As always, I would love to hear any comments or feedback that you may have.

Introducing a New Generation to Wargames

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My childhood friend, Carl Hoffman, introduced me to Avalon Hill wargames. Carl is now a history teacher.

It was my good friend, Carl Hoffman, who lived across the street when I was about 10, who introduced me to Avalon Hill (AH) wargames. The AH wargames of the 1960s were perfectly suited to spark a kid’s imagination. The rules were easy to understand (four pages, big type, with illustrations explaining movement and combat), the Combat Results Table (CRT) was straightforward (and taught us to calculate ratios, too), and we could refight Gettysburg or Waterloo on a rainy afternoon. We learned history (Carl became a history teacher) and problem solving (I became a computer scientist). I’m sure many of us had similar experiences forty or fifty years ago.

For a long time I’ve felt that there is a need for similar ‘introductory wargames’ to engage the next generation of grognards and wargamers. While the hardcore aficionados want more complex and detailed games I’ve also understood that we needed simple, introductory games, to entice a new generation. From the beginning, I have always had a simpler wargame embedded inside of General Staff. Specifically, if we remove all the layers of historical simulation, what remains is a simple introductory wargame.

The Layers of Historical Simulation in General Staff

Each layer of historical simulation can be turned on or off when playing a General Staff scenario. The more options you add, the more historically accurate the simulation becomes. The options are:

Unit strength
1. Unit strength is a value from 1 – 4 with units being reduced in steps.
2. Unit strength is the actual historic number of troops and every individual casualty is tracked.
Combat resolution
1. Simple Combat Resolution Table like the old AH CRT.
2. Complex Combat Resolution Equation taking into effect morale, experience, leadership, terrain, and elevation.
Moving units
1. Units are moved directly by the player.
2. Orders to move units are issued down a chain of command from the top HQ to the subordinate HQ via couriers and the rapidity with which the orders are executed depends on the Leadership Value of the subordinate HQ and subordinate units.
Fog of War (FoW)
1. No Fog of War. The entire map is visible and all units (friend and foe) are displayed on it.
2. Partial FoW. The entire map is displayed and the sum of what all friendly units can see is displayed.
3. Complete FoW. You see only what the commander can see from his HQ and nothing else. All unit positions not directly observable are updated via couriers and are frequently no longer accurate by the time the courier arrives.

So, at it’s most complex (let’s call this a Historical Accuracy level of 100%) this is what the player commanding the Army of the Potomac (Blue) would see (what General George McClellan could actually see through his telescope on the lawn of the Pry House on the morning of September 17, 1862):

Antietam from the perspective of General George B. McClellan at the Pry House on the east bank of the Antietam Creek. This is complete Fog of War and the highest level of historical accuracy. Screen shot. Click to enlarge.

And, interestingly, this view of what McClellan could see is confirmed in The U. S. Army War College Guide to the Battle of Antietam and The Maryland Campaign of 1862 edited by Jay Luvaas and Harold W. Nelson.”General McClellan and his headquarters staff observed the battle from the lawn of the Pry House… Through a telescope mounted on stakes he enjoyed a panorama view of the fighting… He could see Richardson’s division break through the Confederate position at the Bloody Lane. He could not, however, follow the movements of the First and the Twelfth Corps once they disappeared into the East Woods, which masked the fight for the Cornfield, nor did he witness the attempts to seize Burnside’s bridge to the south because the view from the Pry House was blocked by trees and high ground.” – p. 119.

So, the above is the 100% historically accurate view of the battle of Antietam from McClellan’s Headquarters. This is the ‘introductory’ view:

Antietam in ‘Introductory’ mode. Note that unit strengths are represented by one to four icons. Also note the lack of HQs. Screen shot. Click to enlarge.

I first saw the concept of ‘unit steps’ in Jim Dunnigan’s Avalon Hill classic, 1914 and I’m shamelessly using it here. I very much like the simplicity of this system: as units take casualties, they are reduced, in steps, from four icons, to three, to two, etc. I also very much like the idea that this is not an abstraction of the battle of Antietam (or Little Bighorn, or Quate Bras, etc.) but the actual units in their actual locations. This fulfills my requirements for an introductory wargame: historic, teaches tactics and problem solving, easy to play, simple rules, quick to learn and quick to play (I would think a game could easily be played in less than an hour).

Here are some more General Staff scenarios in ‘introductory mode’:

1st Bull Run, 11:30 hours, ‘introductory’ mode. Screen shot. Click to enlarge.

Little Bighorn in ‘introductory’ mode. Screen capture. Click to enlarge.

Quatre Bras in ‘introductory’ mode. Screen capture. Click to enlarge.

I could use your help! Announcing a ‘name the mode’ contest!

From ‘The American Kriegsspiel. Clicking on this image will take you to the Grogheads.com article on William Livermore’s American Kriegsspiel.

I originally called ‘introductory’ mode, ‘Kriegsspiel’ mode because I was reminded of the maps and blocks that Kriegsspiel uses. However, I pretty quickly received some emails from the Kriegsspiel community complaining – and rightfully so – that Kriegsspiel isn’t an introductory game. Absolutely! And if you’ve ever taken a look at the original rule books and tables you would agree, too.

So, here’s my problem (and how YOU can help): I need a new phrase to replace ‘Kriegsspiel mode’. I’ve been using ‘Introductory mode’ but I just don’t like it. I really need a new name for this version. I’m open to any suggestions. How about a completely made up word? ‘Stratego’ would be great if it hadn’t already been used. So, I’m announcing a contest to ‘name this mode’. The winner will receive 2 General Staff coffee mugs. Please email me (Ezra@RiverviewAI.com) with you suggestions. Thank you for your help!