Symmetric Decomposition of Asymmetric Games

Tuyls, Karl, Perolat, Julien, Lanctot, Marc, Ostrovski, Georg, Savani, Rahul ORCID: 0000-0003-1262-7831, Leibo, Joel, Ord, Toby, Graepel, Thore and Legg, Shane (2018) Symmetric Decomposition of Asymmetric Games Scientific Reports, 8 (1). 1015-. ISSN 2045-2322, 2045-2322

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Abstract

We introduce new theoretical insights into two-population asymmetric games allowing for an elegant symmetric decomposition into two single population symmetric games. Specifically, we show how an asymmetric bimatrix game (A,B) can be decomposed into its symmetric counterparts by envisioning and investigating the payoff tables (A and B) that constitute the asymmetric game, as two independent, single population, symmetric games. We reveal several surprising formal relationships between an asymmetric two-population game and its symmetric single population counterparts, which facilitate a convenient analysis of the original asymmetric game due to the dimensionality reduction of the decomposition. The main finding reveals that if (x,y) is a Nash equilibrium of an asymmetric game (A,B), this implies that y is a Nash equilibrium of the symmetric counterpart game determined by payoff table A, and x is a Nash equilibrium of the symmetric counterpart game determined by payoff table B. Also the reverse holds and combinations of Nash equilibria of the counterpart games form Nash equilibria of the asymmetric game. We illustrate how these formal relationships aid in identifying and analysing the Nash structure of asymmetric games, by examining the evolutionary dynamics of the simpler counterpart games in several canonical examples.

Item Type:	Article
Additional Information:	Paper is published in Scientific Reports; https://www.nature.com/articles/s41598-018-19194-4, 2018
Uncontrolled Keywords:	Humans, Models, Statistical, Game Theory, Games, Experimental, Female, Male
Depositing User:	Symplectic Admin
Date Deposited:	23 Jan 2018 09:25
Last Modified:	23 May 2026 01:17
DOI:	10.1038/s41598-018-19194-4
Related Websites:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3016680
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