Abstract

This essay examines how combat trauma can be represented in wargame design without reducing complex psychological experiences to simple morale penalties or diagnostic categories. It argues that meaningful modelling should distinguish immediate stress from accumulated strain while incorporating cohesion, trust, experience, recovery, leadership, and significant events. Psychological consequences should persist across engagements where they influence subsequent decisions, allowing military formations to develop through their individual histories. Such an approach introduces path dependence, nonlinear behaviour, organisational memory, and uncertainty into campaign systems. Ultimately, modelling trauma demonstrates how wargames can represent military units as changing human organisations rather than collections of static capabilities.

The book Achilles in Vietnam: Combat Trauma and the Undoing of Character by Jonathan Shay prompted me to think more seriously about how combat trauma might be modelled within wargames. The essay that follows was stimulated by Shay’s work and by the broader questions it raises about the psychological consequences of combat and how these might be represented on the tabletop. Given the close relationship between the two, I have chosen to post the essay alongside my review of Shay’s book, allowing the review and the resulting exploration of wargame design to be read together.

Introduction

Wargames are necessarily abstractions because no rules system can reproduce the complete physical, psychological, social, and moral experience of warfare, and even the most detailed simulation remains a deliberately constructed representation of selected aspects of reality. Nevertheless, every wargame incorporates assumptions about human behaviour whether those assumptions have been consciously examined by the designer or merely inherited from earlier rules. A unit that continues fighting until it reaches a predetermined casualty threshold, a soldier whose effectiveness remains unchanged throughout repeated engagements, or a formation whose psychological condition is restored through a successful morale test all represent particular interpretations of how human beings behave under extreme conditions.

The relevant question for wargame design is therefore not whether psychology should be modelled, since psychology is already present in almost every rules system through morale, suppression, cohesion, leadership, fatigue, activation, command, and reaction mechanisms. The more important questions concern which psychological processes should be represented, the level at which they should operate, the period over which their consequences should persist, and whether their inclusion materially alters the decisions that the game is intended to explore.¹

Combat trauma presents an especially difficult problem because conventional wargames usually represent the psychological consequences of combat through immediate battlefield mechanisms in which soldiers receive fire, take casualties, lose leaders, become isolated, or encounter unexpected threats and consequently become suppressed, disordered, hesitant, or routed. Such mechanisms can be entirely appropriate for representing immediate battlefield behaviour, but they become less satisfactory when games follow the same soldiers and formations through prolonged periods of combat.

Psychological consequences do not necessarily begin and end within the temporal boundaries of an individual engagement. Stress may be immediate, accumulated strain can develop over repeated operations, relationships can be damaged by casualties or leadership failures, and particular experiences can retain significance long after the physical circumstances that produced them have disappeared. Modern psychological research similarly distinguishes between immediate stress reactions, post traumatic disorders, grief, and moral injury rather than treating them as manifestations of a single process.²

The design problem is therefore substantially more complicated than adding a Trauma statistic or Post Traumatic Stress Disorder characteristic to a unit profile, because such an approach risks reducing a complex range of responses to a negative modifier while confusing clinical diagnosis with simulation design. A more useful approach models the circumstances through which psychological burdens develop, the factors that moderate their effects, the relationships damaged or strengthened by experience, and the consequences that persist across time.

This has implications extending beyond psychological modelling because combat trauma exposes broader weaknesses in traditional approaches to morale, experience, casualties, campaign progression, player knowledge, leadership, simulation validation, and the representation of military organisations themselves. It demonstrates the importance of persistence, uncertainty, relationships, nonlinear effects, and path dependence, while also suggesting that military formations should not be understood merely as collections of present capabilities but as historical organisations whose current behaviour may be shaped by what has previously happened to them.

The Limitations of Traditional Morale

Most wargames already contain some form of psychological model, although it is generally described as morale. A unit comes under fire, takes casualties, loses a commander, encounters a frightening threat, or becomes isolated and is subsequently required to test its willingness or ability to continue functioning. This approach remains valuable because tactical games cannot reasonably reproduce every cognitive and emotional process affecting individual soldiers, and morale therefore provides a convenient abstraction through which fear, exhaustion, confidence, uncertainty, training, leadership, cohesion, and self preservation can be converted into observable battlefield behaviour. Historical studies of combat have repeatedly demonstrated that military effectiveness cannot be understood simply through weapons, numbers, and casualties, and that cohesion, leadership, morale, fatigue, and perceptions of danger strongly influence combat behaviour.³

The problem occurs when a mechanism designed to model immediate battlefield behaviour is expected to represent psychological processes operating over substantially longer periods. Immediate shock is not identical to accumulated combat strain, accumulated strain is not automatically equivalent to psychological trauma, and exposure to traumatic events does not itself establish the presence of a psychiatric disorder.⁴ A soldier who temporarily freezes during intense shelling may recover quickly and experience no significant continuing effects, while another may function effectively throughout the engagement only for psychological consequences to appear afterwards. A third may remain operationally effective throughout prolonged combat while accumulating burdens that influence later behaviour.

Traditional morale systems are principally concerned with immediate performance, asking whether a soldier continues firing, whether a platoon advances, whether a battalion holds its position, or whether a formation obeys an order. Modelling combat trauma introduces the additional question of the longer term human cost involved in repeatedly maintaining that performance, a distinction that is crucial because military effectiveness and psychological wellbeing do not occupy opposite ends of a single scale. Combat experience can improve tactical judgement, threat recognition, fire discipline, use of cover, and the capacity to continue functioning under dangerous conditions, while repeated exposure to death, responsibility, exhaustion, fear, and loss can simultaneously impose increasing psychological burdens.⁵

A system in which experience simply produces progressively better morale therefore captures only part of the relationship between exposure and performance.

Trauma Is Not a Morale Penalty

The most obvious design response is to create a Trauma characteristic and increase it as soldiers experience combat, with higher trauma producing increasingly severe penalties to morale, activation, shooting, movement, or command. The attraction of such a mechanism is obvious because it is easy to administer, but its conceptual weakness is equally important because psychological reactions to warfare are neither uniform nor reliably linear. Individuals exposed to similar circumstances may respond differently, while the same individual may respond differently depending upon previous experience, social relationships, leadership, exhaustion, expectations, and subsequent events. The relationship between combat exposure and later psychological consequences is therefore probabilistic and conditional rather than mechanically deterministic.⁶

Jonathan Shay’s analysis of Vietnam veterans is particularly useful for the wargame designer because it places psychological injury within social and moral relationships rather than reducing it exclusively to an individual’s response to danger. His comparison between the experiences described by veterans and the portrayal of Achilles emphasised the consequences of bereavement, anger, revenge, betrayal, damaged authority, and the destruction of previously accepted moral relationships.⁷ Although subsequent scholarship has expanded and challenged aspects of Shay’s interpretation, particularly in relation to the developing concept of moral injury, the design implication remains important because psychological harm cannot adequately be represented through fear alone. Contemporary moral injury literature similarly emphasises that guilt, shame, betrayal, damaged trust, social alienation, and perceptions of moral transgression may be significant independently of the immediate fear associated with physical danger.⁸

A soldier experiencing accumulated strain may become cautious, another may become more aggressive, another may continue performing extremely effectively while becoming increasingly distrustful of commanders, and another may become unusually protective of the surviving members of the group. Yet another may become more willing to accept personal danger, which means that reducing all of these possibilities to a single morale penalty removes precisely the behavioural variation that makes the subject significant.

A stronger design principle is therefore to model trauma through changing relationships, vulnerabilities, and conditions rather than universal penalties.

Stress, Strain, Trauma and Moral Injury

For design purposes it is useful to distinguish immediate stress, accumulated strain, potentially traumatic experiences, and moral injury. Immediate stress belongs primarily to the tactical battlefield, where artillery fire, casualties, close combat, isolation, surprise, sudden threats, confusion, and uncertainty can temporarily interfere with effective performance. Conventional suppression and morale systems are generally capable of representing these consequences.

Accumulated strain operates over longer periods because repeated danger, insufficient sleep, physical exhaustion, continuous operations, casualties among comrades, inadequate nutrition, uncertainty, and insufficient recovery can increase psychological and physical burdens. Research examining military cohesion and stress has similarly found important relationships among stressful circumstances, strain, cohesion, organisational disintegration, and perceived performance.⁹

Traumatic experiences add another dimension because exposure to death, serious injury, or threats to life is central to contemporary diagnostic understandings of psychological trauma, while military experience also includes events whose significance arises from the meaning attached to them rather than simply the physical danger they present.¹⁰ The concept of moral injury is particularly relevant in this regard because Litz and his colleagues developed an influential model in which potentially morally injurious experiences could involve perpetrating, witnessing, failing to prevent, or becoming aware of conduct that seriously conflicts with an individual’s moral expectations. Psychological consequences could include guilt, shame, withdrawal, difficulties in self forgiveness, and altered understandings of the self and others.¹¹ Subsequent research has considerably expanded the literature while also demonstrating that moral injury remains conceptually distinct from PTSD even though the two may coexist.¹²

More recent scholarship has also returned attention to the social and organisational dimensions of moral injury, particularly the way leadership behaviour, institutional failure, perceptions of betrayal, organisational context, and the response of leaders following difficult events can influence psychological outcomes.¹³ This distinction has considerable importance for wargaming because battlefield rules normally categorise events according to physical consequences, whereas psychological significance does not necessarily follow the same structure.

A shell may cause casualties, a casualty may reduce strength, a dead commander may reduce command efficiency, and a captured objective may increase victory points, yet the psychological significance of those events may differ greatly from their immediately measurable military effects. The death of an established comrade may have consequences different from the death of a recent replacement, accidentally killing civilians may produce very different effects from killing enemy combatants even though the mechanical result in each case may simply be another casualty, and being ordered to abandon wounded soldiers may have relatively little immediate effect upon firepower while seriously damaging confidence in command.

The design implication is therefore that games concerned with psychological consequences need to distinguish between danger, loss, responsibility, relationship, and meaning.

Cohesion and the Unit as a Social Organisation

Traditional wargames frequently conceptualise military units as collections of capabilities, with movement, weapons, protection, training, morale, and command describing what a unit can do. Psychological modelling reveals another dimension because a military unit is also a social organisation in which cohesion, shared identity, confidence in comrades, leadership, and mutual support can influence both combat effectiveness and responses to stressful circumstances.¹⁴ Research involving military populations has repeatedly identified associations between cohesion, morale, leadership, stress, and mental health, although the precise causal relationships are complex and should not be reduced to a universal protective formula.¹⁵

This creates difficulties for casualty based morale systems because removing three figures from a twelve figure platoon is normally treated as equivalent regardless of the identities of those figures. From the perspective of numerical strength, such abstraction may be entirely appropriate, but from the perspective of group relationships it can be misleading because the death of a recently arrived replacement is not necessarily psychologically equivalent to the death of a long serving member of the group. Similarly, the death of a commander may represent more than the loss of a leadership bonus if that commander has become an important focus of trust and group identity.

Campaign design can therefore distinguish between physical strength and social structure without requiring individual psychological profiles for every miniature. A designer might instead identify a small number of significant relationships, such as an established leadership relationship, a veteran core, or particularly important members whose loss has consequences beyond their combat capability. The important theoretical principle is that removing material capability is not always equivalent to removing organisational value.

The same principle applies to replacements because a platoon reduced from thirty soldiers to eighteen and subsequently restored to thirty by the arrival of twelve replacements has regained its numerical establishment without necessarily regaining its previous organisational condition. The survivors possess shared experiences that the replacements do not, existing relationships have been removed, new relationships must develop, and the experienced survivors may possess improved battlefield competence while simultaneously carrying accumulated exhaustion and grief.

Restoring numbers therefore does not automatically restore the formation, a distinction that has implications extending beyond combat trauma to replacement systems, command succession, unit reorganisation, veteran formations, training, and campaign progression.

Leadership, Trust and Betrayal

Leadership provides another example of how psychological modelling challenges conventional assumptions because most wargames treat leadership as inherently beneficial, with commanders adding to morale, generating command points, allowing rerolls, improving activation, or extending command radii. This is mechanically convenient but theoretically incomplete because leadership is not merely command capacity; it is also a relationship between leaders and those expected to follow them.

Competent and trusted leadership can strengthen confidence, cohesion, and resilience, while poor leadership can contribute to uncertainty, resentment, and organisational deterioration. Research among deployed military personnel has found relationships among perceptions of leadership, cohesion, morale, and psychological outcomes, while the developing moral injury literature increasingly recognises leadership and institutional context as important variables.¹⁶ Shay attached particular importance to perceived betrayal by legitimate authority under circumstances involving serious consequences for those subject to that authority.¹⁷ Modern moral injury scholarship does not restrict the concept to this formulation, but leadership betrayal and organisational failure remain important areas of investigation.¹⁸

For design theory, this suggests that leadership should sometimes be modelled through trust rather than solely through command effectiveness. A commander who repeatedly commits an exhausted unit to unsuccessful attacks should create consequences extending beyond the consumption of command points, while a formation promised artillery support that repeatedly fails to arrive may become less willing to rely upon similar assurances. Likewise, a player who abandons a subordinate unit because its sacrifice produces a favourable victory point calculation may have made an entirely rational decision within the existing game system, although soldiers experiencing the decision from within that simulation might interpret the same event very differently.

Campaign systems can therefore allow Trust to change through competent leadership, shared danger, reliable support, adequate rest, successful casualty evacuation, and the fulfilment of commitments, while apparently unnecessary losses, abandonment, contradictory orders, repeated failure, broken promises, or perceived misuse can damage it. Low trust need not produce a universal morale penalty because it might instead affect willingness to undertake particularly dangerous tasks, acceptance of ambiguous orders, recovery following setbacks, or dependence upon local rather than higher authority.

The result is a more sophisticated command model in which the leader ceases to be a mobile positive modifier and instead becomes part of a relationship possessing a history.

Experience and Strain Can Develop Together

Traditional campaign systems tend to reward survival because characters acquire experience, units become veteran, veterans obtain improved statistics, and formations that survive repeated engagements usually become increasingly effective. This produces an obvious progression mechanism but risks turning veteran units into progressively more powerful versions of their inexperienced predecessors.

Combat trauma suggests another possibility in which experience and accumulated strain can increase simultaneously. Repeated combat can improve tactical judgement, weapon handling, observation, use of terrain, and the ability to distinguish genuinely dangerous threats from battlefield noise, while at the same time increasing physical exhaustion, exposing soldiers to further loss, and creating additional psychological burdens.¹⁹ These characteristics do not need to cancel each other because they represent different dimensions of experience.

Experience might improve tactical performance while Strain alters reactions to particular events, Cohesion might remain high even when Strain increases, and Trust might deteriorate while battlefield competence remains excellent. A formation can therefore become more effective and more vulnerable simultaneously, representing an important theoretical movement away from single axis progression.

Instead of units moving steadily from poor to good, inexperienced to veteran, or fresh to exhausted, several independent but interacting variables can describe their development, producing veterans who are different rather than simply better. This distinction is valuable beyond trauma modelling because campaign games frequently suffer from positive feedback in which successful units gain advantages, those advantages produce further victories, and victories produce still greater advantages. Allowing experience to generate benefits while prolonged operations impose different costs can moderate runaway progression without resorting to artificial balancing mechanisms.

Persistence and Multiple Timescales

Combat trauma draws attention to another fundamental design problem because consequences operate across different timescales, while many wargame systems impose an implicit temporal boundary in which suppression exists during the battle, casualties continue into the campaign, victory points survive until the end of the scenario, and almost everything else effectively disappears. This produces an arbitrary distinction based less upon historical processes than upon which mechanisms designers have traditionally chosen to record.

Psychological consequences demonstrate why persistence deserves greater theoretical attention because immediate fear may last seconds or minutes, physical exhaustion may persist for hours or days, reduced cohesion following heavy casualties may continue across several operations, damaged trust can persist until leadership changes or subsequent events repair the relationship, and some consequences may become increasingly significant with repeated exposure.

The designer should therefore consider not merely whether an event has an effect but how long that effect remains relevant. A useful general principle is that a game variable should persist for approximately as long as the phenomenon it represents materially influences the decisions being modelled, a principle that applies equally to ammunition, fatigue, mechanical reliability, intelligence, supply, disease, political support, command relationships, and morale.

Combat trauma therefore reveals a general weakness in systems that treat every consequence as belonging to the same temporal scale.

Path Dependence and the Memory of the Game

Persistence leads directly to path dependence because two formations may possess identical present strength while arriving at that condition through very different histories. One platoon might have suffered steady casualties over several months and incorporated replacements gradually, another might have suffered catastrophic losses during the previous engagement, a third might have avoided severe casualties but undergone weeks of continuous operations without adequate rest, and a fourth might remain physically strong while having lost confidence in its commander.

If their current weapon strength, manpower, and conventional morale ratings are identical, many wargames will treat them as effectively interchangeable, whereas a path dependent model recognises that their present state depends partly upon the routes through which they arrived there.

This is one of the most important theoretical implications arising from trauma modelling because history itself becomes a game variable. The campaign does not merely record results; previous events influence the mechanisms producing future results. A failed attack matters not simply because casualties were sustained but because confidence may have declined, the death of a commander matters not merely because a command bonus disappears but because established trust has been disrupted, and a period of rest matters not simply because physical strength is restored but because accumulated strain may decline. A successful operation can strengthen confidence while simultaneously increasing exhaustion.

The campaign therefore acquires memory, creating a deeper connection between simulation and narrative because the story produced by previous games ceases to be decorative background and instead becomes part of the causal structure governing subsequent play.

Nonlinear Behaviour

Trauma modelling also exposes the limitations of linear modifiers because wargames frequently rely upon additive systems in which veteran status provides a bonus, leadership provides another bonus, casualties create a penalty, and fatigue creates another penalty before the arithmetic determines the final probability. Human behaviour is often less conveniently linear because accumulated strain may produce little observable effect until another significant event occurs, strong cohesion may protect a unit against some forms of stress while making the loss of a particularly important member more consequential, and high trust may allow troops to accept extraordinary demands while perceived betrayal by the same trusted commander may produce greater consequences than disappointment with a leader who was never respected.

Stress, cohesion, strain, disintegration, and performance have consequently been examined in the psychological literature as interacting variables rather than independent additive quantities.²⁰ This suggests that designers should consider thresholds, interactions, conditional effects, and triggers rather than relying exclusively upon permanent modifiers.

A unit with high strain need not receive minus two on every action because high strain might instead alter what happens when another significant event occurs. An experienced and cohesive platoon may operate extremely effectively until a particular loss disrupts the relationships sustaining that performance, producing nonlinear behaviour without requiring complicated mathematics and creating more causally meaningful outcomes because consequences develop from combinations of circumstances rather than arbitrary penalty accumulation.

Emergent Behaviour Rather Than Diagnostic Tables

One temptation when modelling psychological consequences is to create tables of behavioural disorders in which one soldier becomes fearful, another aggressive, another withdrawn, and another unreliable. Such tables can generate variety, but the results frequently have little relationship to the experiences that supposedly produced them.

A stronger design approach produces behaviour emergently. A unit repeatedly left without promised support may become reluctant to conduct unsupported attacks, a formation whose casualties are consistently recovered may develop stronger expectations concerning the recovery of wounded comrades, soldiers who have repeatedly suffered severe losses while attacking prepared positions may become increasingly cautious when ordered to repeat the experience, and a unit serving successfully under the same commander may develop high trust so that the subsequent death or perceived betrayal of that commander has consequences because of the relationship already established.

Behaviour therefore emerges from history rather than being assigned randomly, which also helps distinguish randomness from uncertainty. Randomness is one means of creating uncertainty, but uncertainty does not require arbitrary outcomes because a system in which relationships, accumulated experiences, hidden thresholds, and conditional triggers interact can remain difficult to predict even though its consequences are causally connected to previous events.

This is particularly useful for psychological modelling because it avoids the implication that extreme responses simply appear because an unfortunate die roll has produced a colourful table result.

Recovery Must Be Part of the Model

A trauma system concerned only with deterioration is incomplete because military organisations have repeatedly attempted to manage combat stress and exhaustion through rotation, rest, medical support, training, leadership, social support, replacements, and periods away from immediate danger. The effectiveness of these measures varies according to time, military organisation, available resources, and circumstances, but their existence demonstrates that strain is not simply an irreversible accumulation.²¹

Recovery should therefore become a meaningful campaign process in which rest away from immediate danger may provide more effective recovery than remaining in forward reserve, returning to familiar comrades may have different consequences from transfer to a new formation, competent leadership may facilitate organisational recovery after a disastrous engagement, and replacement may restore manpower while initially disrupting established cohesion.

The distinction between replacement and recovery is particularly important because replacement is primarily administrative, whereas recovery can be physical, psychological, and organisational. Once this distinction is incorporated into the rules, players gain reasons to rotate units before they are physically destroyed, creating a command problem in which a formation may still be capable of fighting even though continuing to employ it is no longer the best long term decision. The player must then decide whether the immediate operational requirement justifies the possible future cost, a problem that is potentially more interesting than another morale test.

Modelling Moral Consequence Without Creating a Diagnostic Game

Moral injury presents particular design difficulties because its significance depends upon interpretation, which makes a table awarding Moral Injury Points whenever civilians are killed or prisoners abandoned conceptually crude and ethically questionable. Such a mechanism assumes that an event has identical psychological meaning for everyone involved and reduces complex moral experience to another resource counter.

A stronger model begins with expectations because military organisations and groups develop assumptions about legitimate conduct, loyalty, authority, responsibility, treatment of comrades, civilians, prisoners, and the enemy. These expectations vary across historical cultures and should not simply reproduce contemporary assumptions.²² An event can become significant when behaviour conflicts with an established expectation, with consequences represented through changes in Trust, Cohesion, Strain, or relationships rather than through the declaration of a clinical diagnosis.

This distinction is important because the wargame designer does not need to decide that a soldier has developed moral injury. The designer can instead represent the possibility that perceived betrayal has damaged trust, that responsibility for a particular event has increased strain, or that participation in an action conflicting with group expectations has altered future behaviour. This is a game model of consequences rather than a psychiatric diagnosis.

The same caution applies to PTSD because the American Psychiatric Association defines PTSD according to specified symptom clusters, duration, exposure requirements, and functional consequences, meaning that exposure to battle does not itself constitute diagnosis.²³ A wargame mechanism in which a failed die roll announces that a miniature has developed PTSD therefore creates a false equivalence between clinical assessment and random game procedure. Terms such as Stress, Strain, Cohesion, Trust, Exhaustion, Grief, and Recovery are considerably more defensible because they describe variables relevant to player decisions without claiming clinical authority that the simulation cannot possess.

Consequences Rather Than Penalties

This leads to another broader design principle because wargames commonly represent undesirable conditions through penalties in which fatigue reduces movement, suppression reduces shooting, casualties reduce morale, and psychological strain could easily become another entry in the same sequence. Not every consequence, however, needs to make a unit universally worse because accumulated experience and strain may instead produce asymmetric behavioural changes.

A cautious veteran formation may become difficult to surprise while being reluctant to conduct exposed movement, strong attachment among surviving members may improve cohesion while making additional casualties particularly significant, and distrust of higher command may reduce compliance with risky orders while increasing local initiative. These are not straightforward advantages or disadvantages because their value depends upon circumstances.

This makes them more interesting as game mechanisms because they create tactical problems rather than merely reducing numerical efficiency. The distinction between penalty and consequence is therefore important because a penalty tells the player that the unit has become worse, while a consequence tells the player that the unit has changed. The latter is particularly appropriate for campaign games because it allows formations to develop distinct identities without requiring extensive special rules.

Player Knowledge and the Omniscient Commander

Psychological modelling also exposes the excessive information available to many wargame players because players often know exactly how many casualties their forces have suffered, the precise morale level of every unit, the location of every commander, the probability associated with every test, and the exact amount of punishment a formation can absorb before breaking. Historical commanders rarely possessed such certainty.

The problem becomes particularly obvious when psychological conditions are represented numerically because if a player knows that a unit possesses seven Stress Points and automatically breaks at ten, psychological uncertainty has disappeared and strain becomes another resource that can be consumed optimally. Hidden information offers an alternative because the player may know that a battalion has endured prolonged operations, suffered important casualties, and received inadequate rest without knowing exactly how it will respond to another severe event.

This can be represented through hidden thresholds, uncertain recovery, cards, qualitative status categories, or information available only when particular circumstances trigger a reaction. The broader theoretical principle is that the simulation may know more than the player, allowing the internal system to contain exact values without displaying them. Players should receive approximately the information that a commander in the represented circumstances could reasonably assess rather than automatically receiving every mechanical quantity used by the model.

This principle has applications well beyond psychological modelling, including logistics, intelligence, enemy strength, equipment reliability, command friction, and political support.

Trauma and Player Agency

Perhaps the strongest reason to model combat trauma is its capacity to change player decisions because good mechanisms generate choices. If trauma simply requires another post battle die roll, it adds administration without necessarily adding meaningful simulation, but if accumulated strain influences whether the player commits a veteran unit, rotates it, withdraws it, reinforces it, changes its commander, or gives it time to recover, psychological consequences become part of command.

Traditional wargames frequently encourage efficient consumption of military formations because casualties become resources exchanged for objectives, and if twenty casualties secure an objective worth more victory points than those losses cost, the decision is rational according to the game. This is not necessarily unrealistic because military commanders do sometimes have to accept losses to achieve objectives, but the problem is that games often define the costs too narrowly.

An assault may capture the objective while exhausting the formation required for the next operation, a successful defence may preserve the tactical position while destroying confidence in leadership, and continually using veteran troops because they possess the best combat ratings may produce immediate success while progressively damaging their future effectiveness. Psychological persistence therefore widens the decision space without requiring the designer to instruct players to behave compassionately, because the system simply needs to ensure that human consequences can become military consequences.

This creates a useful distinction between prescriptive morality and systemic consequence because rules need not tell the player which decision is morally correct, but they can ensure that decisions have effects extending beyond the immediate exchange of casualties and objectives.

Feedback Loops

Combat trauma also demonstrates the importance of feedback because traditional mechanisms are frequently sequential, with fire producing casualties, casualties causing a morale test, morale producing retreat, and the process then effectively resetting. Human organisations are more recursive because casualties can reduce cohesion, reduced cohesion can make subsequent losses more significant, loss of trust can reduce willingness to accept dangerous orders, poor performance can cause commanders to exert additional pressure, and that additional pressure can further damage trust.

The system therefore contains positive feedback capable of accelerating deterioration, while other processes create stabilising feedback through effective leadership, rest, successful operations, social cohesion, adequate support, and recovery. This suggests that design sophistication depends less upon the number of mechanisms than upon the quality of the relationships among them, since a game with six interacting variables may generate richer behaviour than one containing thirty independent modifiers.

Complexity should therefore be understood functionally rather than simply measured by the volume of rules, with the most useful complexity emerging from interaction rather than accumulation.

A Practical Integrated Model

The theoretical argument can be converted into a relatively economical game structure in which six variables are sufficient for many campaign level games. Immediate Stress represents suppression, fear, shock, confusion, and temporary battlefield disruption, changing rapidly and belonging largely within the tactical engagement. Accumulated Strain records the longer term burden produced by repeated exposure, exhaustion, loss, insufficient rest, and other persistent pressures. Cohesion represents the strength of relationships within the group and its capacity to function collectively, while Trust represents confidence in immediate leadership and, where appropriate, higher command or institutions. Experience represents battlefield competence acquired through survival, training, and previous operations, while Recovery represents the capacity to reduce accumulated strain and rebuild organisational effectiveness through rest, leadership, security, time, and social support.

Significant Events can then connect these variables. The death of a trusted commander might affect Cohesion and Trust, a disastrous unsupported attack might increase Strain and reduce Trust, and a successful operation under severe conditions might increase Experience and strengthen Cohesion while simultaneously increasing Strain. A period of effective rest might reduce Strain without removing Experience, while replacement might increase numerical strength while temporarily affecting Cohesion.

The variables therefore describe different dimensions of the formation and should not simply be added together into one final morale score because the relationships among them constitute the model.

Implications for Simulation Validation

Introducing psychological mechanisms also changes how wargames should be validated because it would be unrealistic to demand exact predictive probabilities for complex psychological responses across different periods, cultures, military organisations, and individuals. Validation should instead examine patterns, asking whether repeated exposure without sufficient recovery generally increases vulnerability, whether effective cohesion sometimes moderates the consequences of stress, whether heavy replacement can restore strength without immediately restoring cohesion, whether experience can improve tactical performance while strain also increases, whether poor leadership can damage trust, and whether formations with different histories behave differently even when their numerical strength is similar.

These are more defensible validation questions than asking whether exactly a particular percentage of soldiers should fail a specific test. Simulation theory makes an important distinction between verification and validation because verification concerns whether a model has been implemented according to its intended conceptual structure, whereas validation concerns whether the model provides a sufficiently credible representation of reality for its intended purpose.²⁴

The distinction is essential here because a trauma mechanism might be mathematically flawless while resting upon poor psychological assumptions, whereas a deliberately simple mechanism may be entirely suitable if it generates the patterns and decisions relevant to the purpose of the game. Monte Carlo testing can assist with verification and behavioural analysis because large numbers of trials can identify runaway deterioration, unexpected probability distributions, excessively rapid recovery, universal collapse, or veteran units becoming mechanically useless after predictable numbers of scenarios.

Monte Carlo methods cannot establish whether the psychological theory behind the model is valid, which means quantitative testing must be combined with historical evidence, psychological research, comparative case studies, expert judgement, and explicit examination of assumptions. The broader lesson for wargame design is that mathematical precision is not equivalent to model validity.

The Limits of Quantification

Combat trauma also exposes a fundamental problem in simulation because wargames transform qualitative phenomena into quantitative mechanisms in order to make them operational within a rules system. Morale becomes seven, Cohesion becomes four, and Stress becomes eight, yet these numbers remain representational devices rather than direct measurements of reality.

A unit with Cohesion 8 is not objectively twice as cohesive as one with Cohesion 4 simply because the rules use those values. The numbers exist to produce differences in game behaviour, a distinction between measurement and representation that becomes especially important with psychological mechanisms. A Stress score does not clinically measure stress and a Trust score does not objectively quantify human confidence; both are components of a model whose usefulness depends upon whether they generate plausible patterns of behaviour and meaningful player decisions for the purpose of the game.

False precision should therefore be avoided because more detailed numbers do not automatically produce better simulations.

Scale and Decision Relevance

Not every wargame needs a trauma system because a tactical game representing forty minutes of combat may reasonably restrict psychological modelling to immediate suppression, morale, command, and cohesion when long term trauma lies outside its temporal and conceptual boundaries. A platoon campaign following individual soldiers across months presents a very different situation in which relationships, experience, accumulated strain, leadership, casualties, replacement, and recovery may materially affect the decisions being explored.

Operational games can represent comparable processes at formation level because divisions repeatedly committed to combat without adequate rest can experience declining effectiveness even when replacement systems maintain nominal establishment. Strategic games might represent the institutional dimension through manpower systems, rotation policies, medical services, leadership culture, reinforcement quality, political pressure, and the management of exhausted formations.

The correct level of modelling therefore depends upon decision relevance. Historical phenomena do not need to appear in rules simply because they existed, but they should be modelled when their inclusion changes decisions relevant to the purpose of the game. This provides an important restraint against unnecessary complexity because the design question is not merely whether trauma was historically important, but whether representing its consequences improves the particular simulation.

Ethical Considerations

Combat trauma also requires a degree of ethical restraint because the subject concerns experiences that have caused substantial and continuing suffering to real people. Treating psychiatric conditions as colourful random events or humorous disadvantages would therefore be inappropriate in a serious historical simulation, although automatically omitting psychological consequences also carries assumptions.

A campaign in which soldiers can continue fighting indefinitely provided that physical casualties are replaced implies that human beings effectively return to their previous condition once manpower totals are restored. That is itself a model of war, and psychological mechanisms can challenge this assumption by demonstrating that survival does not necessarily mean remaining unchanged.

The purpose should not be to produce a catalogue of psychiatric symptoms or to pretend that a game can reproduce the lived experience of trauma. Instead, the aim should be to recognise human consequences where they affect military behaviour and command decisions, with responsible abstraction remaining essential throughout.

Wider Implications for Wargame Design Theory

Although combat trauma provides the immediate case, the theoretical implications extend considerably further because military formations are historical systems whose present condition can depend upon previous events. Consequences can operate across multiple timescales, relationships among variables can matter more than isolated characteristics, human behaviour can be nonlinear, uncertainty does not require arbitrary randomness, advantages and disadvantages can coexist within the same characteristic, and players do not necessarily need access to every variable known to the simulation.

Replacing physical resources does not automatically restore organisational condition, and mechanisms should generate decisions rather than merely additional calculations. Most importantly, a unit should not always be understood as a snapshot of current capabilities because it can instead be treated as a path dependent organisation whose current behaviour is partially determined by the sequence of experiences through which it reached its present condition.

This approach has obvious applications beyond trauma because a formation’s logistical reliability can reflect earlier supply decisions, confidence in artillery support can depend upon whether promised fire has previously arrived, command relationships can depend upon successful or unsuccessful cooperation, equipment reliability can reflect accumulated use, civilian attitudes can depend upon previous treatment, and political support can reflect earlier casualties and decisions.

The broader lesson is that historical simulation becomes richer when consequences persist wherever that persistence affects future choices.

Conclusion

Modelling combat trauma presents wargame designers with substantial difficulties, but its greatest contribution may be theoretical rather than mechanical. The principal mistake is to treat trauma as another morale penalty because human responses to warfare vary too greatly and depend too strongly upon circumstances, experience, relationships, leadership, exhaustion, moral interpretation, and opportunities for recovery to be represented adequately through a single declining statistic.

The alternative is not to construct a psychiatric simulation but to model the conditions through which human consequences develop and the ways in which those consequences influence later military behaviour. Immediate battlefield stress can remain within conventional suppression and morale systems, accumulated strain can operate across engagements, cohesion can represent the strength and vulnerability of group relationships, trust can connect command decisions with future responses, experience can improve battlefield competence while strain develops independently, recovery can become a meaningful operational resource, and significant events can connect physical circumstances with social and moral consequences without pretending to diagnose psychiatric disorders.

This produces formations with histories in which a veteran unit ceases to be merely a standard unit possessing better statistics. The battles it has fought, the commanders it has trusted, the comrades it has lost, the replacements it has incorporated, the operations it has endured, and the opportunities for recovery it has received all contribute to its present condition.

Two units beginning a campaign with identical statistics can therefore develop into very different organisations. One may become experienced, cohesive, and confident despite heavy losses, another may remain numerically strong while becoming exhausted and distrustful, and a third may possess excellent tactical ability while becoming increasingly vulnerable to particular events because of accumulated experience and loss. The system does not simply classify units as better or worse, but allows them to become different.

This leads to a wider conclusion about wargame design theory because simulation quality does not depend primarily upon how much information a game contains. It depends upon whether the relationships, processes, uncertainties, persistence, and consequences necessary for the decisions being examined have been represented appropriately.

Combat trauma demonstrates this particularly clearly because it reveals something that conventional wargames can easily obscure. The previous battle matters for reasons extending beyond the ammunition expended, objectives captured, equipment destroyed, and soldiers killed, because it also matters that the survivors experienced it. A wargame capable of remembering that history has moved beyond treating military units as collections of current statistics and begins instead to represent them as human organisations moving through time, which for serious campaign design is a fundamental distinction.

Footnotes

1. Peter P. Perla, The Art of Wargaming: A Guide for Professionals and Hobbyists (Annapolis, MD: Naval Institute Press, 1990), 164–205; Robert E. Shannon, Systems Simulation: The Art and Science (Englewood Cliffs, NJ: Prentice Hall, 1975), 2–8.
2. American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders: DSM 5 TR, 5th ed., text rev. (Washington, DC: American Psychiatric Association Publishing, 2022), section on trauma and stressor related disorders; Brett T. Litz et al., “Moral Injury and Moral Repair in War Veterans: A Preliminary Model and Intervention Strategy,” Clinical Psychology Review 29, no. 8 (2009): 695–706.
3. Anthony Kellett, Combat Motivation: The Behavior of Soldiers in Battle (Boston: Kluwer Nijhoff, 1982), 3–38; Ardant du Picq, Battle Studies: Ancient and Modern Battle, trans. John N. Greely and Robert C. Cotton (New York: Macmillan, 1921), 49–79; S. L. A. Marshall, Men Against Fire: The Problem of Battle Command (Norman: University of Oklahoma Press, 1947).
4. American Psychiatric Association, DSM 5 TR, section on post traumatic stress disorder.
5. Kellett, Combat Motivation, 225–309; Ben Shalit, The Psychology of Conflict and Combat (New York: Praeger, 1988), 54–83.
6. Charles R. Figley, ed., Trauma and Its Wake: The Study and Treatment of Post Traumatic Stress Disorder (New York: Brunner Mazel, 1985), 3–17; American Psychiatric Association, DSM 5 TR.
7. Jonathan Shay, Achilles in Vietnam: Combat Trauma and the Undoing of Character (New York: Atheneum, 1994), 3–21, 39–77; Jonathan Shay, “Learning about Combat Stress from Homer’s Iliad,” Journal of Traumatic Stress 4, no. 4 (1991): 561–579.
8. Litz et al., “Moral Injury and Moral Repair,” 695–706; Sheila Frankfurt and Patricia Frazier, “A Review of Research on Moral Injury in Combat Veterans,” Military Psychology 28, no. 5 (2016): 318–330.
9. James Griffith and Mark Vaitkus, “Relating Cohesion to Stress, Strain, Disintegration, and Performance: An Organizing Framework,” Military Psychology 11, no. 1 (1999): 27–55; James Griffith, “Test of a Model Incorporating Stress, Strain, and Disintegration in the Cohesion Performance Relation,” Journal of Applied Social Psychology 27, no. 17 (1997): 1489–1506.
10. American Psychiatric Association, DSM 5 TR.
11. Litz et al., “Moral Injury and Moral Repair,” 695–706.
12. Frankfurt and Frazier, “Review of Research on Moral Injury,” 318–330; Sonya B. Norman and Shira Maguen, “Moral Injury,” National Center for PTSD, U.S. Department of Veterans Affairs.
13. Sofia Nilsson, “Leadership as Related to Moral Injury in a Military Context: A Systematic Scoping Literature Review,” Trauma, Violence, & Abuse 30, no. 2 (2026); Lucian Tatsa Laur et al., “Exposure to Death in Large Scale Combat Operations: Leadership’s Role in Addressing Stress, Grief and Moral Injury,” Military Psychology (2026).
14. Guy L. Siebold, “The Essence of Military Group Cohesion,” Armed Forces & Society 33, no. 2 (2007): 286–295; Griffith and Vaitkus, “Relating Cohesion to Stress,” 27–55.
15. Norman Jones et al., “Leadership, Cohesion, Morale, and the Mental Health of UK Armed Forces in Afghanistan,” Psychiatry 75, no. 1 (2012): 49–59; Jasmin Kanesarajah et al., “Unit Cohesion, Traumatic Exposure and Mental Health of Military Personnel,” Occupational Medicine 66, no. 4 (2016): 308–315; Geoffrey J. Orme and James E. Kehoe, “Cohesion and Performance in Military Occupation Specialty Training,” Military Medicine 185, nos. 3–4 (2020): e325–e330.
16. Jones et al., “Leadership, Cohesion, Morale,” 49–59; Nilsson, “Leadership as Related to Moral Injury.”
17. Shay, Achilles in Vietnam, 3–21.
18. Nilsson, “Leadership as Related to Moral Injury”; Frankfurt and Frazier, “Review of Research on Moral Injury,” 318–330.
19. Kellett, Combat Motivation, 225–309; Shalit, Psychology of Conflict and Combat, 54–83.
20. Griffith and Vaitkus, “Relating Cohesion to Stress,” 27–55; Griffith, “Test of a Model Incorporating Stress,” 1489–1506.
21. Zahava Solomon, Combat Stress Reaction: The Enduring Toll of War (New York: Plenum Press, 1993), 13–46; Kellett, Combat Motivation, 267–309.
22. Litz et al., “Moral Injury and Moral Repair,” 695–706; Frankfurt and Frazier, “Review of Research on Moral Injury,” 318–330.
23. American Psychiatric Association, DSM 5 TR.
24. Robert G. Sargent, “Verification and Validation of Simulation Models,” Journal of Simulation 7, no. 1 (2013): 12–24; National Research Council, Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st Century Force, Volume 9: Modeling and Simulation (Washington, DC: National Academies Press, 1997), 68–75.

Bibliography

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders: DSM 5 TR. 5th ed., text rev. Washington, DC: American Psychiatric Association Publishing, 2022.

Du Picq, Ardant. Battle Studies: Ancient and Modern Battle. Translated by John N. Greely and Robert C. Cotton. New York: Macmillan, 1921.

Figley, Charles R., ed. Trauma and Its Wake: The Study and Treatment of Post Traumatic Stress Disorder. New York: Brunner Mazel, 1985.

Frankfurt, Sheila, and Patricia Frazier. “A Review of Research on Moral Injury in Combat Veterans.” Military Psychology 28, no. 5 (2016): 318–330.

Griffith, James. “Test of a Model Incorporating Stress, Strain, and Disintegration in the Cohesion Performance Relation.” Journal of Applied Social Psychology 27, no. 17 (1997): 1489–1506.

Griffith, James, and Mark Vaitkus. “Relating Cohesion to Stress, Strain, Disintegration, and Performance: An Organizing Framework.” Military Psychology 11, no. 1 (1999): 27–55.

Jones, Norman, Rachel Seddon, Nicola T. Fear, Pete McAllister, Simon Wessely, and Neil Greenberg. “Leadership, Cohesion, Morale, and the Mental Health of UK Armed Forces in Afghanistan.” Psychiatry 75, no. 1 (2012): 49–59.

Kanesarajah, Jasmin, et al. “Unit Cohesion, Traumatic Exposure and Mental Health of Military Personnel.” Occupational Medicine 66, no. 4 (2016): 308–315.

Kellett, Anthony. Combat Motivation: The Behavior of Soldiers in Battle. Boston: Kluwer Nijhoff, 1982.

Litz, Brett T., Nathan Stein, Eileen Delaney, Leslie Lebowitz, William P. Nash, Caroline Silva, and Shira Maguen. “Moral Injury and Moral Repair in War Veterans: A Preliminary Model and Intervention Strategy.” Clinical Psychology Review 29, no. 8 (2009): 695–706.

Marshall, S. L. A. Men Against Fire: The Problem of Battle Command. Norman: University of Oklahoma Press, 1947.

National Research Council. Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st Century Force. Volume 9: Modeling and Simulation. Washington, DC: National Academies Press, 1997.

Nilsson, Sofia. “Leadership as Related to Moral Injury in a Military Context: A Systematic Scoping Literature Review.” Trauma, Violence, & Abuse 30, no. 2 (2026).

Norman, Sonya B., and Shira Maguen. “Moral Injury.” National Center for PTSD. U.S. Department of Veterans Affairs.

Orme, Geoffrey J., and James E. Kehoe. “Cohesion and Performance in Military Occupation Specialty Training.” Military Medicine 185, nos. 3–4 (2020): e325–e330.

Perla, Peter P. The Art of Wargaming: A Guide for Professionals and Hobbyists. Annapolis, MD: Naval Institute Press, 1990.

Sargent, Robert G. “Verification and Validation of Simulation Models.” Journal of Simulation 7, no. 1 (2013): 12–24.

Shalit, Ben. The Psychology of Conflict and Combat. New York: Praeger, 1988.

Shannon, Robert E. Systems Simulation: The Art and Science. Englewood Cliffs, NJ: Prentice Hall, 1975.

Shay, Jonathan. Achilles in Vietnam: Combat Trauma and the Undoing of Character. New York: Atheneum, 1994.

Shay, Jonathan. “Learning about Combat Stress from Homer’s Iliad.” Journal of Traumatic Stress 4, no. 4 (1991): 561–579.

Siebold, Guy L. “The Essence of Military Group Cohesion.” Armed Forces & Society 33, no. 2 (2007): 286–295.

Solomon, Zahava. Combat Stress Reaction: The Enduring Toll of War. New York: Plenum Press, 1993.

Tatsa Laur, Lucian, Alexander J. Rice, Joscelyn E. Fisher, Mona Al Bizri, James C. West, David M. Benedek, Robert J. Ursano, and Stephen J. Cozza. “Exposure to Death in Large Scale Combat Operations: Leadership’s Role in Addressing Stress, Grief and Moral Injury.” Military Psychology (2026).