View source for Professional wargaming

{{Short description|Used by the military for training or research}}
{{other uses|military simulation}}
[[File:NPS wargame 2018.jpg|right|thumb|upright=1.35|A wargame at the [[US Naval Postgraduate School]] (June 2018).]]
[[File:MCWC-wargame-Lacey-13-cropped.png|right|thumb|upright=1.35|A wargame at the [[US Marine Corps War College]] (April 2019).]]
{{Wargaming}}
{{war}}

A [[wargame]], generally, is a type of strategy game which realistically simulates warfare. A '''professional wargame''', specifically, is a wargame that is used by military organizations to train officers in tactical and strategic decision-making, to test new tactics and strategies, or to predict trends in future conflicts. This is in contrast to [[recreational wargames]], which are designed for fun and competition.

==Overview==
===Definition===
The exact definition of "wargame" varies from one writer to the next and one organization to the next. To prevent confusion, this section will establish the general definition employed by this article.

*A wargame simulates an armed conflict, be it a battle, a campaign, or an entire war. "Business wargames" do not simulate armed conflict and are therefore outside the scope of this article.
*A wargame is adversarial. There must be at least two opposing sides whose players react intelligently to each other's decisions.<ref>''Wargaming Handbook'' (MoD 2017), p. 21</ref> 
*A wargame must have human players.<ref>[[#Perla1990|Perla (1990), ''The Art of Wargaming'']]: "A real wargame must have human players whose decisions affect and are affected by the flow of game events."</ref>
*A wargame does not involve the use of actual troops and armaments. This definition is used by the [[US Naval War College]].<ref name=PerlaNWCdefinition>''War Gamer's Handbook'' (US Naval War College), p. 4: "The [U.S. Naval War College's War Gaming Department] uses the Perla (1990) definition, which describes war gaming as "...a warfare model or simulation whose operation does not involve the activities of actual military forces, and whose sequence of events affects and is, in turn, affected by the decisions made by players representing the opposing sides" (Perla, 1990, p. 164). By doing so, this differentiates a war game from a training exercise, which uses real forces."</ref> Some writers use the term "live wargames" to refer to games that use actual troops in the field,<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 270: "''Live'' wargames are the next oldest. Everything from medieval jousts to Red Flag exercises are live wargames because actual forces engage in (simulated) combat, adjudicated by nonlethal means."</ref> but this article shall instead refer to these as [[field training exercise|field exercises]].
*A wargame is about tactical or strategic decision-making. A game that exercises only the player's technical skills, such as a combat flight simulator, is not a wargame.

Still, some professional wargamers feel that the term "game" trivializes what they see as a serious, professional tool. One of these was [[Georg von Reisswitz]], the creator of ''[[Kriegsspiel]]'' and the father of professional wargaming, but he stuck with the word "game" because he could not think of a better term.<ref>{{harvp|Heistand|1898}}: "The one thing which did not satisfy Von Reisswitz was the word "game;" but not finding anything to take its place he retained it."</ref> In the US Army, many preferred the term "map maneuvers" (in contrast to "field maneuvers"). At the [[US Naval War College]], some preferred the terms "chart maneuvers" (when simulating campaigns) and "board maneuvers" (when simulating battles), although the term "war game" was never officially proscribed.<ref name=Little1912>William McCarty Little (1912), quoted in [[#Perla1990|Perla (1990), ''The Art of Wargaming'']]: "In embarking on this lecture I would like to say, by way of preface, that the name Game, War Game, has had much the same depreciating effect as the term Sham Fight has had with regard to field maneuvers. To avoid this, the Army has had recourse to the expression Map Maneuver. We, of the Navy, may in like manner say Chart Maneuver, and we have lately decided so to do."</ref><ref>[[#Lillard2016|Lillard (2016), ''Playing War'']], p. 46: "The Big Game, generally a series of maneuvers played in stages set in the same scenario, started with chart maneuvers for logistics planning, search, and screening, and it culminated in a large-scale tactical board maneuver."</ref>

===Professional wargames vs commercial wargames===
Professional wargames tend to have looser rules and simpler models than recreational wargames, with an umpire arbitrating situations based on personal knowledge. If the umpire is highly knowledgeable about warfare (perhaps they are a veteran), then such wargames can achieve a higher degree of realism than wargames with rigid rulesets. In a recreational wargame, such looseness would lead to concerns over fairness, but the point of a professional wargame is education, not competition. Having simple, loose rules also keeps the learning curve small, which is convenient since most officers have little or no wargaming experience.

Likewise, there is less concern regarding "balance" when determining each player's armaments and strategic advantages.  In a commercial wargame, the rules are usually designed to ensure that the players' armies are of equal strength to ensure fairness, but professional wargames will tailor each side's capabilities to the scenario to be investigated, and warfare in the real world is rarely fair.

As professional wargames are used to prepare officers for actual warfare, there is naturally a strong emphasis on realism and current events. Historical wargames are wargames set in the distant past, such as World War II or the Napoleonic Wars&mdash; simulating these wars realistically may be of interest to historians, but are of little use to the military. [[Recreational wargame]]s may take some creative liberties with reality, such as simplifying models to make them more enjoyable, or adding fictional armaments and units such as [[orcs]] and wizards, making them of little use to officers who must fight in the real world.

Military organizations are typically secretive about their current wargames, and this makes designing a professional wargame a challenge. Secrecy makes it harder to disseminate corrections if the wargame has already been delivered to the clients. Whereas a commercial wargame might have thousands or even millions of players, professional wargames tend to have small player bases, which makes it harder for the designers to acquire feedback. As a consequence, errors in wargame models tend to persist.<ref>"Creveld (2013), ''Wargames'': "Much of the data that goes into the programs is classified: as a result, checking on whether it is correct is difficult, and errors, once they have crept in, tend to stay. Secrecy also makes it hard to update the games as needed."</ref><ref>[[#Perla1990|Perla (1990), ''The Art of Wargaming'']]: "Unlike those in the wargaming hobby, professional wargamers work in a relatively closed society. One organization's games are not freely available for all to try, critique and modify. Professional wargame designers may document their games (usually in classified publications), but they seldom describe the design process they employed to create them."</ref>

Although commercial wargame designers take consumer trends and player feedback into account, their products are usually designed and sold with a take-it-or-leave-it approach. Professional wargames, by contrast, are typically commissioned by the military that plans to use them. If a wargame is commissioned by several clients, then the designer will have to juggle their competing demands. This can lead to great complexity, high development costs, and a compromised product that satisfies nobody.<ref>Creveld (2013), ''Wargames'': "One is the need to satisfy the requirements of many different user organizations each of which does not wish to buy the game off the shelf but actively attempts to pull it in its own direction. Often the outcome is great complexity and compromises that end up, like the famous camel that was created by a committee, by satisfying nobody."</ref>

Commercial wargames are under more pressure to deliver an enjoyable experience for the players, who expect a user-friendly interface, a reasonable learning curve, exciting gameplay, and so forth. By contrast, military organizations tend to see wargaming as a tool and a chore, and players are often bluntly obliged to use whatever is provided to them.<ref>Creveld (2013), ''Wargames'': "Finally, those who design, manufacture, and market games in the commercial world are obliged to pay attention to users' demands, such as ease of play and creating a good interface between player and game. Their counterparts working in, or for, the military, are not nearly as affected by these concerns. On occasion, this can lead to bad games that people simply do not want to play."</ref>

==Design concepts==
===Models===
The term "model" can mean two things in wargaming. One is the conceptual models that describe the properties, capabilities, and behaviors of the things the wargame attempts to simulate (weapons, vehicles, troops, terrain, weather, etc.). The other meaning, from [[miniature wargaming]] (a form of [[recreational wargaming]]), is physical models, i.e. sculptures of soldiers, vehicles, and terrain; which generally serve an aesthetic purpose and have little if any consequence on the simulation. Professional wargames rarely use physical models because aesthetics aren't important to the military and the scale at which professional wargames typically play make physical models impractical. Therefore, this article will focus on conceptual models.

A wargame is about decision-making, not about learning the technical capabilities of a particular weapon or vehicle. Therefore, a well-designed model will not describe something beyond what a player needs to know to make effective decisions. Players should not be burdened with cumbersome calculations, because this slows down the game and distracts the players. If a player makes a bad decision, it should only be because of poor strategic thinking, not some forgotten rule or arithmetic error, otherwise the game will yield less reliable insights. If the wargame is computer-assisted, then sophisticated models are feasible because they can be written into the software and processed quickly by the computer. For manual wargames, simplicity is paramount.

===Level of war===
In a tactical-level wargame, the scope of the simulated conflict is a single battle. ''[[Kriegsspiel]]'', the original professional wargame, is an example of a tactical-level wargame. The wargames of the Western Approaches Tactical Unit (see below) were also tactical-level, simulating submarine attacks on a merchant convoy.

In a strategic-level wargame, the scope of the simulated conflict is a campaign or even an entire war. An example is the "Chart Maneuvers" practiced by the [[US Naval War College]] during the 1920s and 1930s, which most often simulated a hypothetical war in the Pacific against Japan. Another example is the Sigma wargames played in the 1960s to test proposed strategies for fighting the Vietnam War. Battles are resolved through simple computation. The players concern themselves with higher-level, strategic concerns such as logistics and diplomacy.

==Utility==
===General strengths and limitations===
In comparison to field exercises, wargames save time and money. They can be organized quickly and cheaply as they do not require the mobilization of thousands of men, their armaments, and logistics systems.

Some wargames can be completed more quickly than the conflicts they simulate by compressing time. In a naval wargame, the players need not wait days for their fleets to sail across the ocean, they could just advance the time-frame to the next decision they must make. This is particularly advantageous for strategic-level games, in which the simulated conflict might last months. A tactical-level wargame that has very cumbersome computations might take longer to play out than the battle it represents (this problem afflicted the original ''[[Kriegsspiel]]'').

Wargamers can experiment with assets that their military does not actually possess, such as alliances that their country does not have, armaments that they have yet to acquire, and even hypothetical technologies that have yet to be invented.

For example: After [[World War I]], Germany was forced to downsize its armed forces and outright give up certain weapons such as planes, tanks, and submarines. This made it difficult, if not impossible, for German officers to develop their doctrines through field exercises. The Germans greatly expanded their use of wargaming to compensate. When Germany began openly rearming in 1934, its officers already had fairly well-developed theories on what armaments to buy and what organizational reforms to implement.<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 282</ref>

Wargames cannot be used to predict the progression and outcome of a war as one might predict the weather. Human behavior is too difficult to predict for that.  Wargames cannot provoke the anxiety, anger, stress, fatigue, etc. that a commander will experience in actual combat and thus cannot foresee the effects of these emotions on his decision-making.<ref>[[#Perla1990|Perla (1990), ''The Art of Wargaming'']]: "The first thing to remember is that wargames, exercises, and analysis involve no actual fighting. Because this is the case, none of these tools can capture all of the human elements of real combat. Military history is full of examples in which courage, fear, morale, and leadership provided the decisive determinants of defeat or victory. Wargames and exercises, by requiring participants to process information and make decisions in the presence of uncertainty and under the pressure of time, provide greater opportunities for exploring some of these factors than does analysis, but even their ability to re-create the stresses of combat is limited."</ref> That said, no training tool can replicate the emotional experience of war, so this is not a specific flaw. Another issue that can produce "wrong" predictions is that a commander may do things differently in the field precisely because he was dissatisfied with the decisions he made in the wargames.<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 280-281: "More importantly, Blue may do so because the decision makers, not liking how a wargame turned out, have addressed on wargaming the reason, in order to change how the actual event will turn out."</ref>

===Education===
Wargames are a cost-effective way of giving officers the experience (or something resembling experience) of making decisions as a leader in an armed conflict. This is the oldest application of wargaming. The actual effectiveness of wargaming in this regard&mdash;turning a bad strategist into a good one&mdash;is difficult to measure because officers use many tools to hone their decision-making skills and the effect of wargaming is difficult to isolate.<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 282-283: "Wargaming can be useful in developing the potential of individuals. This being the oldest application of wargaming, one might assume that its usefulness has the most historical support. Unfortunately, if history includes an account of a prince with a record of losing battles taking up chess and then going on to victory, I have yet to find it. The increase in military effectiveness with the founding of staff and war colleges might be seen as pertinent. Still, wargaming made up just one part of the individuals’ studies, making the effect of gaming alone difficult to isolate."</ref>

In this context, wargames are used to help players understand the decision-making process of wartime command. Wargames can help players master through practice certain routine skills such as how to discuss ideas, share intel, and communicate orders. Wargames can present the players with intellectual challenges that they cannot receive from books or in the classroom: an enemy who reacts unpredictably and intelligently to the player's decisions,

Wargames train players to evaluate situations and make decisions faster. They teach players how to discuss ideas, and the protocols for sharing intel and communicating orders.<ref>Vego (2012), ''German War Gaming'', p. 115: "The Germans emphasized the importance of concise and logical presentation of ideas, in making decisions and issuing orders based on them. Another purpose of a war game was training in techniques and procedures of writing and issuing orders."</ref> They teach the players how to cope with incomplete, delayed, incorrect, or superfluous information. They teach the player how to cope with an unpredictable foe who reacts intelligently to their decisions.

Wargames can also help familiarize the players with the geography of areas where they might eventually have to fight in. This was an oft-cited justification for wargaming at the US Naval War College.<ref>[[#Lillard2016|Lillard (2016), ''Playing War'']], p. 110: "..they provided an opportunity for students to familiarize themselves with geographic areas of future strategic interest."</ref>

===Research and planning===
Wargames can be used to prepare grand strategic plans and develop [[military doctrine|doctrine]] with a low risk of the enemy becoming aware of these developments and adapting. A problem that any military faces when learning through hard experience (actual warfare) is that as it gets better at fighting the enemy, the enemy will adapt in turn, modifying their own armaments and tactics to maintain their edge. Live exercises have a similar weakness as the enemy can spy on them to learn what is being tested. But wargames can be done in good secrecy, so the enemy cannot know what ideas are being developed.<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 285</ref>

Wargames can help a military determine what armaments and infrastructure it should acquire (there is substantial historical evidence to support this particular assertion).<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 282: "Wargames can be useful as aids in making specific decisions on the acquisition of military forces and militarily significant infrastructure. The historical record is particularly strong in this area."</ref>

For instance: In the 1920s, American military planners believed that America could win a war with Japan quickly by simply sailing an armada across the Pacific and knocking out the Japanese navy in a few decisive battles.<ref>[[#Lillard2016|Lillard (2016), ''Playing War'']], p. 70: "The Mahanian strategy was to gather the battle fleet in a large formation, steam forward to a point where the enemy would be compelled to bring out their fleet, use the firepower of dreadnought battleships to overwhelm the enemy battle line, and then blockade the enemy’s home waters. [...] This doctrine called for the U.S. Navy to steam directly across the central Pacific, engage the Japanese fleet in force, and defeat them as quickly as possible while the garrison defending the Philippines withdrew to the Bataan peninsula and fought a delaying action."</ref> But when this strategy was tested in wargames, it routinely failed. Japan held off the assault until the American armada exhausted itself, and then counter-attacked. The wargames foretold that a war with Japan would instead be a prolonged war of attrition, and America would need advance bases in the western Pacific where its warships could get resupplied and repaired.<ref>[[#Lillard2016|Lillard (2016), ''Playing War'']], p. 106: "Repeated experiments with all manner of approaches to the ORANGE war led to the same conclusion—that the U.S. Navy’s thruster strategy for the Pacific was not workable with the fleet in hand. The realization summarized in Van Auken’s report led the Research Department to conduct a comprehensive review of all of the trans-Pacific games played between 1927 and 1933. The Department compared BLUE and ORANGE losses in each game as a function of the BLUE force’s approach route, ORANGE defensive strategy, force composition (either actual or in accordance with the London Treaty), and BLUE force speed of advance. They concluded that variations in each of these factors made little difference in the game outcomes, and that BLUE would be at a major disadvantage in trying to fight their way past ORANGE-held island bases to reach the Philippines, simply because their continued advance put them farther and farther from their support infrastructure."</ref><ref>{{harvp|Vlahos|1986|p=13}}: "[The US Navy] developed in gaming the doctrine and practice of progressive transoceanic offensive operations, where there had been before mere transit itinerary."</ref> Such an infrastructure would require making alliances with friendly countries such as Australia, New Zealand, and the British Empire.<ref>[[#Lillard2016|Lillard (2016), ''Playing War'']], p. 103: "A major point stressed by the Research Department was that the BLUE fleet’s approach route highlighted the previously underappreciated need to receive fuel, provisioning, and basing support from allies in the region, namely England, Australia, and the Netherlands East Indies, and the need to repair underwater battle damage closer to the theater of operations."</ref>

Wargames can also be used to develop the potential of new technology. In order to wield a new technology optimally, it is not enough for a military to merely have it, but also develop good tactics and know how to organize around it. If the enemy isn't exploring the same issues in their own wargames, then one can gain a significant edge over the enemy when war breaks out by deploying a more mature [[military doctrine|doctrine]].<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 286-287</ref>

An example is German submarine doctrine in the World Wars. In World War I, submarines were a new thing and nobody knew how best to use them, and Germany developed its submarine doctrine on the go. The German navy at the time did not use wargames and tested new ideas immediately against the British. Consequently, for every incremental innovation in submarine warfare that the Germans deployed, the British quickly developed a counter-measure and kept pace, and this limited the impact of submarines in World War I. During the inter-war years, the German navy experimented extensively with new submarine tactics in wargames (in tandem with field exercises) and developed the [[Wolfpack (naval tactic)|"wolf-pack"]] doctrine to defeat the anti-submarine counter-measures that had been developed during World War I (notably the [[convoy|convoy system]]). The British, by contrast, did not experiment with submarines in their own wargames because they thought that their established counter-measures were sufficient.<ref name=Parkin2019c7>[[#refParkin2019|Parkin (2019). ''A Game of Birds and Wolves'', chpt. 7]]: "Despite the fact that during the First World War the Germans had used submarines to great effect to disrupt the convoys bringing food and supplies to Great Britain, neither U-boats nor convoys featured in the wargames of 1935. [...] ‘Submarines were not mentioned,’ Roberts wrote of the games he was tasked with designing. ‘Nor were convoys and attacks on them. Nobody connected Hitler’s rise … to the possibility of another Battle of the Atlantic. Nor did I, to be absolutely fair.’"</ref> The Germans entered the war with a whole bag of new tricks, and it took some time for the British to catch up.<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 45: "Germany’s wolf-pack doctrine for U-boats is an even clearer example of the power of its interwar application of live and map-based wargames. Britain ended World War I with the submarine threat substantially under control, and it correctly estimated technological advances during the interwar period would favor antisubmarine warfare. Britain was accordingly almost unconcerned about the German submarine threat when World War II began. Unfortunately for Britain, Germany’s submarine doctrine, which was largely developed even before Germany acquired U-boats, allowed it to win the first several rounds of the Battle of the Atlantic, sinking shipping far faster than the Allies could build replacements."</ref>

==History==
===The Reisswitzian wargame===
{{Main|Kriegsspiel}}
Around the turn of the 19th century, a number of European inventors created wargames based on chess. These games used pieces that represented real army units (infantry, artillery, etc.) and the squares on the board were color-coded to represent different terrain types (rivers, marshes, mountains, etc.). Basing these games on chess made them attractive and accessible to chess players,<ref>In a letter from Hellwig (an early wargame inventor), dated 26 September 1801, quoted in {{harvp|Heistand|1898}}:<br/>"The first thought which presented itself to my mind was that the learning of my game ought not to be burdened with too many details if it was to fulfill its mission.  I judged from the first that I should achieve my object in the quickest way if I took for its basis the game of chess, in favor with so many distinguished persons of all ranks. My idea was to adapt, as far as possible, the game of chess to my own game, in order so to interest amateurs that they would at least give mine a trial. [...] experience confirmed the wisdom of my expectations, for chess players were the first to welcome my invention [...]"</ref> but also made them too unrealistic to be taken seriously by the army. The grid forced the terrain into unnatural forms, such as rivers flowing in straight lines and bending at right angles; and only a single piece could occupy a square at a time, even if that square represented a square mile.<ref>[[#Peterson2012|Peterson (2012), ''Playing At War'']]:"...the grid imposed on the wargames of Hellwig and Venturini significantly limited the capacity of these systems to represent the position of troops realistically. Effectively, in a board wargame divided into squares of a scale mile across, there is only one position that troops within a mile’s range could hold."</ref><ref>{{harvp|Reisswitz|1824}}: "In these early attempts the landscape had been forced into squares and triangles, with rivers, seas, villages, mountains, valleys and so on pushed out of their natural shapes and into straight lines. In the same way movements of troops, the representation of troop types, the effect of firepower, were also severely modified in such a way that a realistic picture of events failed to be produced."</ref>

[[File:Kriegsspiel 1824.jpg|thumb|right|A reconstruction of the wargame developed in 1824 by Reisswitz]]
In 1824, a [[Prussian army]] officer named [[Georg von Reisswitz]] presented to the Prussian General Staff a wargame that he and his father had developed over the years. It was a highly realistic wargame designed strictly for use as a professional tool of training, and not for leisure. Instead of a chess-like grid, this game was played on accurate paper maps of the kind the Prussian army used. This allowed the game to model terrain naturally and simulate battles in real locations. The pieces could be moved across the map in a free-form manner, subject to terrain obstacles. The pieces, each of which represented some kind of army unit (an infantry battalion, a cavalry squadron, etc.), were little rectangular blocks made of lead. The pieces were painted either red or blue to indicate the faction it belonged to. The blue pieces were used to represent the Prussian army and red was used to represent some foreign enemy&mdash;since then it has been the convention in professional wargaming to use blue to represent the faction to which the players actually belong to. The game used dice to add a degree of randomness to combat. The scale of the map was 1:8000 and the pieces were made to the same proportions as the units they represented, such that each piece occupied the same relative space on the map as the corresponding unit did on the battlefield.

The game modeled the capabilities of the units realistically using data gathered by the Prussian army during the [[Napoleonic Wars]] and various field exercises. Reisswitz's manual provided tables that listed how far each unit type could move in a round according to the terrain it was crossing and whether it was marching, running, galloping, etc.; and accordingly the umpire used a ruler to move the pieces across the map. The game used dice to determine combat results and inflicted casualties, and the casualties inflicted by firearms and artillery decreased over distance. Unlike chess pieces, units in Reisswitz's game could suffer partial losses before being defeated, which were tracked on a sheet of paper (recreational gamers might call this "[[hitpoint]] tracking"). The game also had some rules that modeled morale and exhaustion.

Reisswitz's game also used an umpire. The players did not directly control the pieces on the game map. Rather, they wrote orders for their virtual troops on pieces of paper, which they submitted to the umpire. The umpire then moved the pieces across the game map according to how he judged the virtual troops would interpret and carry out their orders.<ref>[[#Peterson2012|Peterson (2012), ''Playing At War'']]:"In addition to establishing the general idea and the composition of the opposing forces, the umpire serves as an intermediary for virtually all actions in the game: all movements, all communications and all attacks channel through the umpire, in writing. The players transmit written orders, authored to their units in the persona of a commander, and for the most part the umpire enjoys significant leeway in deciding how these orders will be interpreted."</ref> When the troops engaged the enemy on the map, it was the umpire who rolled the dice, computed the effects, and removed defeated units from the map. The umpire also managed secret information so as to simulate the fog of war. The umpire placed pieces on the map only for those units which he judged both sides could see. He kept a mental track of where the hidden units were, and only placed their pieces on the map when he judged they came into view of the enemy.

Earlier wargames had fixed victory conditions, such as occupying the enemy's fortress. By contrast, Reisswitz's wargame was open-ended. The umpire decided what the victory conditions were, if there were to be any, and they typically resembled the goals an actual army in battle might aim for. The emphasis was on the experience of decision-making and strategic thinking, not on competition. As Reisswitz himself wrote: "The winning or losing, in the sense of a card or board game, does not come into it."<ref>{{harvp|Reisswitz|1824}}</ref>

In the English-speaking world, Reisswitz's wargame and its variants are called ''[[Kriegsspiel]]'', which is the German word for "wargame".

===German professional wargaming (1824–1914)===
[[File:Joseph Nash Kriegsspiel.png|right|thumb|Prussian officers playing ''[[Kriegsspiel]]'' (illustr. August 1872).]]
Reisswitz showed his wargame to the Prussian king and his General Staff in 1824. They were greatly impressed. General [[Karl von Mueffling]] wrote: "It’s not a game at all! It's training for war. I shall recommend it enthusiastically to the whole army." The king decreed that every regiment should play ''[[Kriegsspiel]]'', and by the end of the decade every regiment had purchased materials for it.<ref>Vego (2012), ''German War Gaming'', p. 110: "General Karl von Mueffling (1775–1851), chief of the general staff (1821–29) in Prussia, exclaimed, "It's not a game at all! It’s training for war. I shall recommend it enthusiastically to the whole army." He fulfilled that promise: a royal decree directed every regiment in the Prussian army to play the game regularly. By the end of the 1820s each Prussian regiment was purchasing with state funds materials for war gaming."</ref> By the 1850s it had become very popular in the army.<ref>Vego (2012), ''German War Gaming'', p. 110: "By the 1850s the ''Kriegsspiel'' had gained great popularity in the German military and some interest in the militaries of other countries."</ref> ''Kriegsspiel'' was therefore the first wargame to be treated as a serious tool of training and research by a military organization.

Aside from official military venues, ''Kriegsspiel'' was also played in a number of private clubs around the country, which were mainly patronized by officers but also had civilian members, so ''Kriegsspiel'' was certainly being played in a recreational context. The first such club was the Berlin Wargame Association.{{efn|{{langx|de|Berliner Kriegsspiel-Verein}}}} In 1828, [[Helmuth von Moltke the Elder|General von Moltke the Elder]] joined the Magdeburg Club and became its manager.

Over the years, other officers updated Reisswitz's game to reflect changes in technology and doctrine. A particularly noteworthy variant was ''free Kriegsspiel'', developed in 1876 by General [[Julius von Verdy du Vernois]]. Vernois was frustrated by the cumbersome rules of traditional ''rigid Kriegsspiel''. They took a lot of time to learn and prevented experienced officers from applying their own expertise. The computations also slowed down the game; sometimes, a session would take longer to play than the actual battle it represented. Vernois advocated dispensing with the rules altogether and allowing the umpire to determine the outcomes of player decisions as he saw fit. Dice, rulers, computations, etc. were optional. This rules-free variant, of course, depended more heavily on the competence and impartiality of the umpire. The relative merits and drawbacks of rules-heavy and freeform wargaming are still debated to this day.

===Wargaming spreads around the world===
Prussian wargaming attracted little attention outside [[Prussia]] before 1870. Prussia was considered a second-rate power and wargaming an unproven novelty. That changed in 1870, when Prussia defeated France in the [[Franco-Prussian War]]. Many credited Prussia's victory to its wargaming tradition.<ref>[[#Perla1990|Perla (1990), ''The Art of Wargaming'']]:"In the aftermath of the 1870-1871 Franco-Prussian War, European and world military opinion suddenly became enamored of things German, including Kriegsspiel, to the use of which many experts attributed the German victories."</ref> The Prussian army did not have any significant advantage in weaponry, numbers, or troop quality, but it was the only army in the world that practiced wargaming.<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 278: "During the wars of German unification, Prussian wargaming appears to have provided a significant advantage. How else can Prussia’s lopsided victories be explained? Prussian forces were more often than not outnumbered, weapon advantages were mixed, and training methods were similar, though some think Prussia had an advantage in the education of staff officers. At this time, though, the Prussian military had a monopoly on second-generation wargaming and had integrated it into its staff education and its staff planning methods, especially at the higher levels."</ref> Civilians and military forces around the world now took a keen interest in German wargames, which foreigners referred to as ''Kriegsspiel'' (the German word for "wargame"). The first ''Kriegsspiel'' manual in English, based on the system of Wilhelm von Tschischwitz, was published in 1872 for the British army and received a royal endorsement.<ref name=Peterson2012>[[#Peterson2012|Peterson (2012), ''Playing At War'']]</ref> The world's first recreational wargaming club was the University Kriegspiel [''sic''] Club, founded in 1873 at [[Oxford University]] in England. In the United States, [[C. A. L. Totten|Charles Adiel Lewis Totten]] published ''[[Strategos (game)|Strategos, the American War Game]]'' in 1880, and William R. Livermore published ''The American Kriegsspiel'' in 1882, both heavily inspired by Prussian wargames. In 1894, the US Naval War College made wargaming a regular tool of instruction.<ref name=Perla1990_NWC1894>[[#Perla1990|Perla (1990), ''The Art of Wargaming'']]: "In 1894, under newly appointed President Captain Henry Taylor, gaming became an integral and permanent part of the course of study for all students."</ref>

===Wargaming at the US Naval War College (1919–1941)===
[[File:NWC-wargame-1950s.tif|right|thumb|A wargame at the [[US Naval War College]]. This photo was taken in the 1950s, but strongly resembles the wargames played in the 1930s.]]
The [[US Naval War College]] is a [[staff college]] where American officers of all ranks go to receive postgraduate training. Since 1894, wargaming has been a regular tool of instruction there.<ref name=Perla1990_NWC1894/> Wargaming was brought to the Naval War College by [[William McCarty Little]], a retired [[US Navy|Navy]] lieutenant who had likely been inspired after reading ''The American Kriegsspiel'' by W.R. Livermore. Livermore was stationed nearby at Fort Adams, and he and Little cooperated to translate the ideas behind ''[[Kriegsspiel]]'' to naval warfare.<ref>[[#Perla1990|Perla (1990), ''The Art of Wargaming'']]: "Little's budding interest in wargaming was almost certainly stimulated by his association with army Major W. R. Livermore, author of ''The American Kriegsspiel'', who was stationed across the harbor from the Naval War College in Fort Adams."</ref>

After World War I, the Navy suffered severe budget cuts that prevented it from upgrading and expanding its fleet. This limited its ability to conduct naval exercises. Wargaming thus became a vital means of testing hypothetical strategies and tactics.<ref>[[#Lillard2016|Lillard (2016), ''Playing War'']], p. 107: "This happened in spite of the assertion by the school that the wargames were not laboratories for war plan development. In reality they could not help but be, simply because of their ubiquity and their demonstrated potential to provide a low-cost way to exercise naval thought in an era of parsimony. The game represented one of the only ways that issues of pressing interest to the navy could be investigated in a systematic way..."</ref> Another problem was that by the time America entered [[World War II]] in 1941, none of the Navy's senior officers had any meaningful combat experience because the Navy had not been involved in any war for over 20 years. However, almost all of them had participated in wargames at the Naval War College, so they had plenty of virtual combat experience.<ref>[[#Lillard2016|Lillard (2016), ''Playing War'']], p. 8: "In 1941 none of them had any meaningful naval combat experience, but almost every one of them had practiced tactics and strategy in the War College's wargame environment."</ref> The fact that America defeated Japan in [[World War II]] despite these shortcomings, is evidence for the value of the wargaming. After the war, [[Chester Nimitz|Admiral Nimitz]] said that the wargames predicted every tactic the Japanese used except for the ''[[kamikazes]]'' (a somewhat hyperbolic assertion).<ref>[https://usnwcarchives.org/repositories/2/archival_objects/65005 Chester Nimitz, in a speech at the US Naval War College, 10 October 1960].</ref><ref>[[#Lillard2016|Lillard (2016), ''Playing War'']], p. 1</ref>

The [[Naval War College]] organized two broad classes of wargames: "chart maneuvers", which were strategic-level games; and "board maneuvers", which were tactical-level games. The chart maneuvers were about fleet movements, scouting and screening operations, and supply lines.<ref>[[#Lillard2016|Lillard (2016), ''Playing War'']], p. 47</ref> The board maneuvers simulated battles in detail, with the aid of model ships. Most of the wargames were played on the floors of lecture halls, as they needed more space than any table could provide.

The two most frequently played scenarios were a war with Japan and a war with Britain. Japan was code-named ORANGE, Britain was code-named RED, and America was code-named BLUE. Neither the students nor the staff at the Naval War College expected a war with Britain.<ref>[[#Lillard2016|Lillard (2016), ''Playing War'']], p. 45: "While lecture subjects and student diaries reflect awareness of the volatile situation in postwar Europe, none of these documents provide any indication that naval officers of the time ever imagined that the United States might go to war with England."</ref> It's possible that the US Navy didn't imagine getting into any sort of serious naval conflict in the Atlantic with anyone, and that it simulated wars against Britain simply because it saw the [[Royal Navy]] as its role model.<ref>[[#Vlahos1980|Vlahos (1980), ''The Blue Sword'']], p. 103, 107</ref> A war with Japan, on the other hand, was a real concern, and as the years passed the wargames were increasingly played against ORANGE.

In case of a war with Japan, the US Navy's grand strategy was to send an armada straight across the Pacific and quickly defeat the Japanese navy in one or two decisive battles.<ref>[[#Lillard2016|Lillard (2016), ''Playing War'']], p. 70: "This doctrine called for the U.S. Navy to steam directly across the central Pacific, engage the Japanese fleet in force, and defeat them as quickly as possible while the garrison defending the Philippines withdrew to the Bataan peninsula and fought a delaying action."</ref> The wargamers at the College tested this strategy extensively, and it routinely failed. In 1933, the Navy's Research Department reviewed the wargames played from 1927 to 1933 and concluded that the fundamental problem was that the armada over-extended its supply lines. The BLUE armada would exhaust itself, and ORANGE would recover and counter-attack.<ref>[[#Lillard2016|Lillard (2016), ''Playing War'']], p. 105-106: "With the same basic results obtained despite experiments with different tactics, new ship types, and a variety of approach routes, commentary by the new Research Department reflected a growing realization that the thruster strategy was too costly for BLUE. At the same time, ORANGE, while in many cases suffering losses that were comparable to BLUE, usually ended the games in a better position to recover from those losses and mount a counterattack.</ref> After this, the wargamers at the College abandoned the old doctrine and instead developed a more progressive strategy, which involved building a logistics infrastructure in the western Pacific and making alliances with regional countries. By the mid-1930s, the wargames resembled very much what the Navy later experienced in the [[Pacific War]].<ref>[[#Lillard2016|Lillard (2016), ''Playing War'']]: "Game records from the period show that by the middle of the 1930s the students and staff were simulating a Pacific war very much like the one they ended up fighting in the 1940s."</ref>

The wargames also produced tactical innovations, most notably the "circular formation". In this formation, as it was used in [[World War II]], an aircraft carrier was surrounded by concentric circles of cruisers and destroyers. This formation concentrated anti-aircraft fire, and also was easier to maneuver than a [[line of battle]] because all the ships could turn at once with a signal from the central ship. The circular formation was first proposed in September 1922 by [[Commander (United States)|Commander]] Roscoe C. MacFall. Initially, the wargamers at the College used a battleship as the central ship, but this was eventually supplanted by the aircraft carrier. [[Chester Nimitz]], who was a fellow student that same year, was impressed by what the circular formation could do, and Nimitz played a pivotal role in making it Navy doctrine.<ref>{{harvp|Potter|1976|p=138}}: "Recalled Nimitz afterward, "We were all impressed with the things you could do from a circular formation." To Nimitz alone, however, fell the distinction of introducing the new formation to the fleet."</ref>

On the other hand, the wargamers at the Naval War College failed to develop good submarine doctrine. They didn't have a good understanding of what submarines could do. Unlike the German navy, the US Navy had no significant experience with submarine warfare. Most of the time, the players used submarines as a screening force that sailed ahead of the main formation. Players rarely used submarines in independent operations, and never to attack commercial shipping as German wargamers were doing at the time.<ref>[[#Lillard2016|Lillard (2016), ''Playing War'']]: "Strategically, submarines were still something of an unknown quantity in interwar period navies. Only Germany had any significant experience in a submarine campaign..."</ref>

For a few years after the end of World War II, wargaming almost ceased in America. At the Naval War College, wargaming dropped to about 10% of its pre-war level.<ref>[[#Caffrey2019|Caffrey (2019). ''On Wargaming'']], p. 74: "...immediately after World War II, wargaming at the Naval War College dropped to about 10 percent of its prewar levels."</ref>

===German wargaming after World War I===
The [[Treaty of Versailles]] greatly restricted the size of Germany's armed forces and outright banned certain weapons such as planes, tanks, and submarines. This made it difficult if not impossible for the German military to develop their doctrines through field exercises. The Germans greatly expanded their use of wargaming to compensate, and between 1919 and 1939, the German military used wargaming more heavily than any other in the world.<ref>Vego (2012), ''German War Gaming'', p. 114: "Between 1919 and 1939 the German military, more than any other, used war gaming as the main means for educating and training its officer corps. The reason was that the Versailles Treaty of 1919 put severe restrictions on Germany’s forces. Among other things, the size of the new German military, the Reichswehr, was put at a hundred thousand, including four thousand officers. The general staff was formally dissolved, although its main functions survived under different names. Tanks, aircraft, and U-boats were prohibited."</ref> By the time Germany began openly rearming in 1934, its officers already had fairly well-developed theories on what armaments to buy and what organizational reforms to implement.<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 282: "At a negligible incremental cost, Germany greatly increased the depth and scope of wargaming in its armed forces. This had the added benefit that when the armed forces were allowed to expand, buy new weapons, and activate new units (or did so anyway), they knew from their wargames what weapons and forces would have the greatest impact."</ref>

German wargaming at this time was restricted to tactical and operational-level play. Hitler discouraged strategic-level games, as he was confident enough in his own ability to make strategic judgments. Over the course of the war, Germany fought well at the tactical and operational level but made many bad strategic decisions.<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 46</ref>

During World War 1, the British learned to protect their ships from German submarines by moving them in convoys which were escorted by submarine-hunting ships. The convoy system proved effective against German submarines, which typically operated alone. During the inter-war years, the German navy developed the [[Wolfpack (naval tactic)|"wolf-pack"]] doctrine by which German submarines would attack convoys in groups to confuse and overwhelm the escorts. These ideas were tested in a combination of wargames and naval exercises. [[Karl Doenitz]], who would later command German submarine operations during [[World War II]], organized a series of wargames held during the winter of 1938-39, and from the results he concluded that it would be best for a wolf-pack attack to be coordinated by a designated command submarine rather than a commander onshore. He also concluded that Germany needed 300 submarines to effectively destroy British shipping, and that Germany's existing submarine fleet would at most inflict "pin-pricks".<ref>{{harvp|Doenitz|1959}}</ref><ref>Vego (2012), ''German War Gaming'', p. 120-121</ref>

After World War II, wargaming ceased in Germany, as well as in the other Axis powers. Germany didn't even have an army until 1955, so they saw little need to wargame. When [[West Germany]] established its new army in 1955, they had so few officers with wargaming experience that the German War College asked the US Air Force to provide it an officer with wargaming experience.<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 71</ref>

===British naval wargaming during World War II===
[[File:WATU wargame 1.png|right|thumb|A naval wargame at [[Western Approaches Tactical Unit|WATU]] (1942). The male players on the right are looking through peepholes in a screen which hides the enemy board.]]
In January 1942, the [[British Royal Navy]] established a naval tactical analysis unit called the [[Western Approaches Tactical Unit]] (WATU), which was tasked with developing ways to counter the German submarine [[Wolfpack (naval tactic)|"wolf-packs"]] that were devastating shipping convoys in the Atlantic. It was based in [[Liverpool]], directed by [[Gilbert Roberts (Royal Navy officer)|Captain Gilbert Roberts]], and staffed mainly by young women from the [[Women's Royal Naval Service]]. Their primary analytical tool was wargaming.

The staff at WATU used wargames to test various hypothetical submarine tactics against virtual convoys, and if a certain tactic proved consistently effective and produced outcomes similar to what the actual convoys were reporting, WATU assumed that is what the Germans were in fact doing. The staff at WATU would then design counter-measures and test them in wargames. WATU operated week-long courses wherein naval captains would be instructed in anti-submarine tactics through wargames.

It's uncertain exactly how many German submarines were sunk thanks to WATU's tactics, but at the close of the war, several British admirals asserted that WATU had played a decisive role in Germany's defeat.<ref>These were Admirals Max Horton and Percy Noble. See [[#refParkin2019|Parkin (2019). ''A Game of Birds and Wolves'', Postscript]] and [[#refWilliams1979|Williams (1979). ''Captain Gilbert Roberts'', p. 179]]</ref> Had the German submarine threat to merchant shipping not been thwarted, Britain would have been forced to capitulate to the Germans for lack of food and other necessary imports.

What makes WATU a remarkable episode in the history of wargaming is that it was the first time in which wargames were used to analyze scenarios that were occurring in an ongoing war and develop solutions that were deployed immediately in the field. This was made possible by communications technologies such as telephone and radio.

===Soviet Union===
The Soviets inherited their wargaming techniques from tsarist officers, who favored the rigid form of wargaming pioneered by Reisswitz. Interestingly, the Soviets typically played wargames not on flat maps, but on three-dimensional model battlefields. Soviet wargames typically comprised only a single turn. The players would describe their plan to the umpires, who would then adjudicate the battle all the way to conclusion. This meant the players could not react to what the enemy was doing. This approach was optimal for decision-support but poor for developing the players' thinking skills.<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 55: "The slow, detailed adjudication of these wargames that was optimal for decision support was poorly suited to developing the thinking skills of Soviet officers."</ref><ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 61-62: "Soviet games typically centered on terrain models. Using each side’s plans for the entire mission, the umpires, using incredibly detailed and cumbersome procedures, would the adjudicate the operation all at once, all the way to its conclusion. Only then would the two teams be called back and walked through the operation, step by step. Essentially, these were one-move wargames."</ref>

Immediately after the end of World War II, there was a precipitous drop in wargaming in armed forces all over the world. The exception was the Soviet Union. The Soviets actually expanded their wargaming and made them more rigorous.<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 63: "Only inside the Soviet Union did wargaming expand and become more rigorous."</ref> The Soviets launched a massive effort to compile data from the [[Eastern Front (World War II)|war on the Eastern Front]] to make their wargames more valid.<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 78: "Even before the cessation of hostilities, they launched a massive effort to collect and compile operational data from their part of World War II, the “Great Patriotic War,” to increase the validity of their wargaming."</ref>

During the Cold War, the Soviets allowed officers from other communist countries to attend its military schools, and wargaming was part of the curriculum. Using techniques learned in the Soviet Union, North Vietnamese officers wargamed their attacks against South Vietnam and her allies, and were able to coordinates complicated attacks without the need for radio communications by memorizing timetables.<ref>[[#Caffrey2019|Caffrey (2019), ''On Wargaming'']], p. 85</ref>

===The Navy Electronic Warfare Simulator (1958)===
[[File:NWC_wargame_1958.jpg|right|thumb|The Navy Electronic Warfare Simulator (1958).]]

The first computerized wargaming system was the Navy Electronic Warfare Simulator, which became operational in 1958 at the [[US Naval War College]]. The computer system, being from the pre-microchip era, spanned three floors. The game rooms were designed to the resemble the command centers where the Navy coordinated its fleets.<ref>[[#Peterson2012|Peterson (2012). ''Playing At War'']]: "An early and well-documented example is the “Navy Electronic Warfare Simulator,” or NEWS, conceived in 1945 and operational by 1958. Its four thousand miles of wire and thirteen thousand electronic tubes, marshaled across three floors of a building, at a cost of around US$10M exceeded the means of even the most enthusiastic hobby wargame clubs. Much of this cost reflected the sophistication of the facilities housing the players and umpires, which replicated command centers then in service to run a real-time game in the actual spaces of command."</ref><ref>[[#Perla1990|Perla (1990), ''The Art of Wargaming'']]: "The modernization plans laid in the late 1940s came to fruition in 1958 when the Navy Electronic Warfare Simulator, the NEWS, was commissioned. The NEWS occupied the three floors of the central wing of the War College's Sims Hall, and had taken thirteen years and $7.25 million to complete."</ref> When the system was first made operational in 1958, the Navy discovered that it could not model recent advances in military technology. For instance, it could not model ships moving faster than 500 knots. The system had taken 13 years to develop and, like most computers from that era, was difficult to reprogram or upgrade (it predated punch-cards). A variety of improvisational gimmicks were required to run wargames for the contemporary era.<ref>[[#Perla1990|Perla (1990). ''The Art of Wargaming'']]: "Unfortunately, from the day it first came on line NEWS suffered from several limitations. It had originally been conceived of as little more than a fancy modern update of the game board (one of its preliminary names had been the Electronic Maneuver Board System), and this ancestry showed all too clearly. [...] To get around these limitations, a whole host of "scaling factors and other gimmicks" were developed."</ref>

===SIGMA war games (United States, 1962–1967)===
Between 1962 and 1967, the US military{{efn|Specifically, the Joint War Games Agency, an agency of the Joint Chiefs of Staff.}} conducted a series of strategic-level wargames known as the [[Sigma war games]] to test proposed strategies for fighting the [[Vietnam War]]. 

The Sigma I-64 and II-64 games, conducted in 1964, were designed to test the proposed strategy of gradually escalating pressure on North Vietnam until it gave up out of economic self-interest.<ref>[[#refMcMaster1998|McMaster (1998), ''Dereliction of Duty'', chpt. 8]]: "The objective of the attacks and pressures is not to destroy the nation’s ability to provide support but rather to affect its calculation of interests."</ref> Graduated escalation was supposed to avoid accidentally provoking an intervention by China or the Soviet Union.<ref>[[#refMcMaster1998|McMaster (1998), ''Dereliction of Duty'', chpt. 4]]: "Rusk, agreeing with McNamara, believed that graduated pressure would never present “Peking or Moscow with enough of a change in the situation to require them to make a major decision… in terms of intervening in [Vietnam].” Rusk believed that applying force in carefully controlled gradations would help to “limit the war to Viet Nam.”"</ref> It would also avoid making [[Lyndon B. Johnson|President Johnson]] look like a warmonger.<ref>[[#refMcMaster1998|McMaster (1998), ''Dereliction of Duty'', chpt. 4]]: "McNamara’s strategy of graduated pressure seemed to “solve” the president’s problem of not losing Vietnam while maintaining the image that he was reluctant to escalate the war. If the Chiefs had successfully pressed with the president their position that the United States needed to act forcefully to defeat the North, they might have forced a difficult choice between war and withdrawal from South Vietnam."</ref> This "graduated pressure" would primarily involve bombing North Vietnam and sending troops into South Vietnam.<ref>[[#refFord1998|Ford (1998), ''CIA and the Vietnam Policymakers'', p. 48]]: "Rostow reasoned that the threat, or the actual implementation, of US bombing would "work" for essentially two reasons: the DRV now had an industrial base its leaders would not wish destroyed, and they would fear being driven by US attacks into a position of "virtual vassalage" to Communist China."</ref>

The wargames predicted that this strategy would be ineffective. In the simulations, the bombings did not diminish North Vietnam's capacity nor its desire to support the [[Viet Cong]]. The Viet Cong did not require much in the way of supplies anyway, and they got most of their supplies from captured villages within South Vietnam.<ref>Sigma II-64 final report: "Most important, perhaps, was the feeling that the Viet Cong might well be able to continue operating in SVN for a considerable period of time using existing stockpiles, captured stores and weapons, and levies on the country, despite destruction of major military and industrial facilities in NVN. Cited were examples of the VC provisioning from the larder of RVN villages."</ref> North Vietnam's economy was almost entirely agricultural, so the loss of what little industry it had caused little political turmoil. They preferred to seek revenge, and so sent more troops into South Vietnam. This forced America into a protracted ground war, which led to erosion of public support that eventually forced America's withdrawal.

The findings of the 1964 wargames were ignored by policymakers. One reason was that Secretary of Defense [[Robert McNamara]] did not appreciate the methodology of the games, which relied on subjective evaluations by the umpires (even though these men were seasoned officers and diplomats). McNamara preferred mathematical and statistical analysis. He therefore did not bring the findings to [[Lyndon B. Johnson|President Johnson's]] attention.<ref>[[#refMcMaster1998|McMaster (1998), ''Dereliction of Duty'', chpt. 5]]: "McNamara sent to the president, however, only those assessments that supported his conception of prosecuting the conflict in Vietnam. Robert McNamara was not interested in the outcome of SIGMA I [...] the SIGMA test, largely a subjective evaluation based on military experience and diplomatic expertise, did not appeal to McNamara’s penchant for systematic and quantitative analysis."</ref> Another reason was that Johnson's strategists did not like the proposed alternatives. Escalating the pressure too much could have drawn the Soviet Union or China into the war, and abandoning the war would have humiliated America.<ref>[[#refMcMaster1998|McMaster (1998), ''Dereliction of Duty'', chpt. 8]]: "The growing consensus behind the strategic concept of graduated pressure overpowered SIGMA II’s unpromising conclusions because the president and his advisers were unwilling to risk either disengagement or escalation. In their minds the rash application of force could be disastrous and lead, in the worst-case scenario, to nuclear war with the Soviet Union. Doing nothing would lead to defeat in South Vietnam and an associated loss of credibility that could undermine the West’s alliance structure and result in defeat in the Cold War."</ref>

The Johnson administration went on to apply their strategy of graduated pressure in Vietnam, and the outcome of the war proved very similar to what the wargames had foretold.<ref>[[#refMcMaster1998|McMaster (1998), ''Dereliction of Duty'', chpt. 5]]: "The outcome of the game was eerily prophetic."</ref> In their post-mortems of the Vietnam War, numerous historians have cited the dismissal of the Sigma wargames as one of many important failures in planning that led to America's defeat.<ref>Bill Fawcett, Harold P. Ford, and HR McMaster are cited in this article.</ref>

==References==
===Footnotes===
{{notelist}}
{{reflist}}

===Bibliography===
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*{{cite book |author=E. B. Potter |date=1976 |title=Nimitz |publisher=Naval Institute Press |isbn=0-87021-492-6 |ref={{harvid|Potter|1976}} |url-access=registration |url=https://archive.org/details/nimitz00pott }}
*{{cite book |author=B. von Reisswitz |year=1824 |title=Anleitung zur Darstellung militairische Manover mit dem Apparat des Kriegsspiel |trans-title=Instructions for the Representation of Military Manoeuvres with the Kriegsspiel Apparatus |language=de |ref={{harvid|Reisswitz|1824}}}} ([https://www.scribd.com/document/201901872/B-Von-Reisswitz-1824-Wargames-Rules-of-the-Prussian-Army translation by Bill Leeson, 1989])
*{{cite speech |author=Chester W. Nimitz |title=An Address to Naval War College |date=10 Oct 1960 |location=Naval War College, Newport, RI, USA |url=https://usnwcarchives.org/repositories/2/archival_objects/65005 }}
*{{cite book |author=George Leopold von Reiswitz |year=1812 |title=Taktisches Kriegs-Spiel oder Anleitung zu einer mechanischen Vorrichtung um taktische Manoeuvres sinnlich darzustellen |trans-title=Tactical War Game - or, instruction to a mechanical device to simulate tactical maneuvers |language=de |publisher=Gädicke |url=https://digital.staatsbibliothek-berlin.de/werkansicht?PPN=PPN796686009&PHYSID=PHYS_0005 |ref={{harvid|Reisswitz Sr.|1812}}}}
*{{cite encyclopedia
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}}
*{{cite magazine |author=Heinrich Ernst Dannhauer |date=11 July 1874 |title=Das Reiswissche Kriegsspiel von seinem Beginn bis zum Tode des Erfinders 1827 |trans-title=The Reiswitzian Wargame from its Inception until the death of the inventor in 1827 |url=https://babel.hathitrust.org/cgi/pt?id=mdp.39015076659534;view=1up;seq=555 |magazine=Militär-Wochenblatt |volume=59 |number=56 |pages=527–532 |ref={{harvid|Dannhauer|1874}}}}
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*{{cite book |author=Karl Doenitz |translator=George Weidenfeld |year=2012 |orig-year=first published 1959 |title=The Memoirs of Karl Doenitz: Ten Year and Twenty Days |publisher=Frontline Books |isbn=9781783031429 |ref={{harvid|Doenitz|1959}}}}
*{{cite book |title=Wargames: From Gladiators to Gigabytes |author=Martin van Creveld |publisher=Cambridge University Press |year=2013 | isbn=9781107036956 |ref={{harvid|Creveld|2013}}}}
*{{cite journal|author=Matthew B. Caffrey Jr. |date=2019 |title=On Wargaming: How Wargames Have Shaped History and How They May Shape the Future |journal=The Newport Papers |issue=43 |publisher=Naval War College Press (US) |isbn=978-1-935352-65-5 |url=https://digital-commons.usnwc.edu/newport-papers/43/ |ref=Caffrey2019}}
*{{cite book |author=Michael Vlahos |year=1980 |title=The Blue Sword: The Naval War College and the American Mission, 1919-1941 |publisher=Naval War College Press |url=https://digital-commons.usnwc.edu/historical-monographs/4/ |ref=Vlahos1980}}
*{{cite journal|author=Michael Vlahos |date=1986 |title=Wargaming, an Enforcer of Strategic Realism: 1919-1942 |journal=Naval War College Review |volume=39 |issue=2 |url=https://digital-commons.usnwc.edu/nwc-review/vol39/iss2/3/|ref={{harvid|Vlahos|1986}}}}
*{{cite journal |author=Milan Vego |date=2012 |title=German War Gaming |journal=Naval War College Review |volume=65 |issue=4 |url=https://digital-commons.usnwc.edu/nwc-review/vol65/iss4/10/ |ref={{harvid|Vego|2012}}}}
*{{cite book| editor1=Pat Harrigan |editor2=Matthew G. Kirschenbaum |year=2016 |title=Zones of Control: Perspectives on Wargaming |publisher=MIT Press |isbn=9780262033992 |ref={{harvid|Harrigan|Kirschenbaum|2016}}}}
*{{cite journal |author=Paul Schuurman |year=2017 |title=Models of war 1770–1830: the birth of wargames and the trade-off between realism and simplicity |journal=History of European Ideas |volume=43 |issue=5 |pages=442–455 |doi=10.1080/01916599.2017.1366928 |ref={{harvid|Schuurman|2017}}|doi-access=free |hdl=1765/101998 |hdl-access=free }}
*{{cite book |author1=Peter P. Perla |author2=Raymond T. Barrett |title=An Introduction to Wargaming and its Uses |year=1985 |url=http://apps.dtic.mil/dtic/tr/fulltext/u2/b098178.pdf |archive-url=https://web.archive.org/web/20200305144914/http://www.dtic.mil/dtic/tr/fulltext/u2/b098178.pdf |url-status=live |archive-date=March 5, 2020 |ref={{harvid|Perla|1985}}}}
*{{cite book |title=Peter Perla's The Art of Wargaming: A Guide for Professionals and Hobbyists |author=Peter P. Perla |editor=John Curry |publisher=The History of Wargaming Project |year=2012 |orig-year=first published 1990 |isbn=978-1-4716-2242-7 |ref=Perla1990}}
*{{cite book |author=Philip Sabin |date=2012 |title=Simulating War: Studying Conflict Through Simulation Games |publisher= A&C Black |isbn=9781441185587 |ref={{harvid|Sabin|2012}}}}
*{{cite book |author1=Rolf F. Nohr |author2=Stefan Böhme |title=Die Auftritte des Krieges sinnlich machen |publisher=Appelhans-Verlag Braunschweig |year=2009 |isbn=978-3-941737-02-0 |ref={{harvid|Nohr|Bohme|2009}}}}
*{{cite book |editor=Shawn Burns |year=2013 |title=War Gamers' Handbook: A Guide for Professional War Gamers |url=http://apps.dtic.mil/dtic/tr/fulltext/u2/1001766.pdf |archive-url=https://web.archive.org/web/20180728110627/http://www.dtic.mil/dtic/tr/fulltext/u2/1001766.pdf |url-status=live |archive-date=July 28, 2018 |publisher=US Naval War College |ref={{harvid|Burns|2013}}}}
*{{cite book |author=Simon Parkin |year=2019 |title=A Game of Birds and Wolves: The Secret Game that Won the War |publisher=Hodder & Staughton |isbn=9781529353051 |ref=refParkin2019}}
*{{cite book |author=Tristan Donovan |title=It's All a Game: The History of Board Games from Monopoly to Settlers of Catan |publisher=Macmillan |year=2017 |isbn=9781250082732 |ref={{harvid|Donovan|2017}}}}
*{{cite book |author=Walter R. Borneman |date=2012 |title=The Admirals: Nimitz, Halsey, Leahy, and King--The Five-Star Admirals Who Won the War at Sea |publisher=Little, Brown and Company |isbn=978-0-316-20252-7 |ref={{harvid|Borneman|2012}}}}
*{{cite book |author=Thomas B. Allen |year=1987 |title=War Games: The Secret World of the Creators, Players, and Policy Makers Rehearsing World War III Today |publisher=McGraw Hill |isbn=9780070011953 |ref=refParkin2019}}
*{{cite book |author=H. R. McMaster |year=1998 |title=Dereliction of Duty: Johnson, McNamara, the Joint Chiefs of Staff, and the Lies That Led to Vietnam |publisher=Harper Perennial |isbn=9780060929084 |ref=refMcMaster1998}}
*{{cite book |author=Mark Williams |year=1979 |title=Captain Gilbert Roberts R. N. and the Anti-U-Boat School |publisher=Cassell |isbn=0-304-30386-0 |ref=refWilliams1979}}
*{{cite book |author=Harold P. Ford |year=1998 |title=CIA and the Vietnam Policymakers: Three Episodes 1962-1968 |publisher=Central Intelligence Agency |url=https://books.google.com/books?id=Dbtomz1aZEUC |ref=refFord1998}}
*{{cite book |author=Bill Fawcett |year=2009 |title=How to Lose a War: More Foolish Plans and Great Military Blunders |publisher=Harper Collins |isbn=9780061900709 |ref=refFawcett2009}}
*[[:File:Sigma II-64 final report.pdf|Sigma II-64 final report]] (1964), Joint Chiefs of Staff

{{Wargames|state=expanded}}
{{Authority control}}

[[Category:Wargames]]
[[Category:Military exercises and wargames]]
[[Category:Combat modeling]]