Peace war game is an

iterated game In game theory, a repeated game is an extensive form game that consists of a number of repetitions of some base game (called a stage game). The stage game is usually one of the well-studied 2-person games. Repeated games capture the idea that a p ...

originally played in academic groups and by computer simulation for years to study possible strategies of cooperation and aggression. As peace makers became richer over time it became clear that making war had greater costs than initially anticipated. The only strategy that acquired wealth more rapidly was a " Genghis Khan", a constant aggressor making war continually to gain resources. This led to the development of the "provokable nice guy" strategy, a peace-maker until attacked.N.R. Miller
"Nice Strategies Finish First: A Review of ''The Evolution of Cooperation''"
''

Politics and the Life Sciences ''Politics and the Life Sciences'' (PLS) is a peer-reviewed academic journal that was first published in 1982 with Thomas Wiegele as the editor. It is published by Cambridge University Press on behalf of the Association for Politics and the Life ...

'', Association for Politics and the Life Sciences, 1985. Multiple players continue to gain wealth cooperating with each other while bleeding the constant aggressor. The Hanseatic League for trade and mutual defense appears to have originated from just such concerns about seaborne raiders. The peace war game is a variation of the

iterated prisoner's dilemma The Prisoner's Dilemma is an example of a game analyzed in game theory. It is also a thought experiment that challenges two completely rational agents to a dilemma: cooperate with their partner for mutual reward, or betray their partner ("def ...

in which the decisions ( Cooperate,

Defect A defect is a physical, functional, or aesthetic attribute of a product or service that exhibits that the product or service failed to meet one of the desired specifications. Defect, defects or defected may also refer to: Examples * Angular defec ...

) are replaced by (

Peace Peace is a concept of societal friendship and harmony in the absence of hostility and violence. In a social sense, peace is commonly used to mean a lack of conflict (such as war) and freedom from fear of violence between individuals or groups. ...

War War is an intense armed conflict between states, governments, societies, or paramilitary groups such as mercenaries, insurgents, and militias. It is generally characterized by extreme violence, destruction, and mortality, using regular o ...

). Strategies remain the same with

reciprocal altruism In evolutionary biology, reciprocal altruism is a behaviour whereby an organism acts in a manner that temporarily reduces its fitness while increasing another organism's fitness, with the expectation that the other organism will act in a similar m ...

, "

Tit for Tat Tit for tat is an English saying meaning "equivalent retaliation". It developed from "tip for tap", first recorded in 1558. It is also a highly effective strategy in game theory. An intelligent agent, agent using this strategy will first coope ...

", or "provokable nice guy" as the best deterministic one. This strategy is simply to make peace on the first iteration of the game; after that, the player does what his opponent did on the previous move. A slightly better strategy is "Tit for Tat with forgiveness". When the opponent makes war, on the next move, the player sometimes makes peace anyway, with a small probability. This allows an escape from wasting cycles of retribution, a motivation similar to the Rule of Ko in the game of Go. "Tit for Tat with forgiveness" is best when miscommunication is introduced, when one's move is incorrectly reported to the opponent. A typical

payoff matrix In game theory, normal form is a description of a ''game''. Unlike extensive form, normal-form representations are not graphical ''per se'', but rather represent the game by way of a matrix. While this approach can be of greater use in identifyin ...

for two players (A, B) of one iteration of this game is: : Here a player's resources have a value of 2, half of which must be spent to wage war. In this case, there exists a Nash equilibrium, a mutually best response for a single iteration, here (War, War), by definition heedless of consequences in later iterations. "Provokable nice guy's"

optimality Optimality may refer to: * Mathematical optimization * Optimality Theory in linguistics * optimality model In biology, optimality models are a tool used to evaluate the costs and benefits of different organismal features, traits, and characterist ...

depends on iterations. How many are necessary is likely tied to the payoff matrix and probabilities of choosing. A subgame perfect version of this strategy is "Contrite Tit-for-Tat" which is to make peace unless one is in "good standing" and one's opponent is not. Good ("standing" assumed) means to make peace with good opponents, make peace when bad, or make war when good and opponent is not.

Herbert Gintis Herbert Gintis (February 11, 1940 – January 5, 2023) was an American economist, behavioral scientist, and educator known for his theoretical contributions to sociobiology, especially altruism, cooperation, epistemic game theory, gene-culture co ...

, ''Game Theory Evolving: A Problem-centered Introduction to Modeling Strategic Behavior'',

Princeton University Press Princeton University Press is an independent publisher with close connections to Princeton University. Its mission is to disseminate scholarship within academia and society at large. The press was founded by Whitney Darrow, with the financia ...

, 2000, p. 133

Notes

{{game theory Dilemmas Moral psychology Non-cooperative games Peace and conflict studies Social psychology Thought experiments

See also

Notes