An open reproducible framework for the study of the iterated prisoner's dilemma

(1) Overview Title An open reproducible framework for the study of the iterated prisoner's dilemma. Abstract The Axelrod library is an open source Python package that allows for reproducible game theoretic research into the Iterated Prisoner's Dilemma. This area of research began in the 1980s but suffers from a lack of documentation and test code. The goal of the library is to provide such a resource, with facilities for the design of new strategies and interactions between them, as well as conducting tournaments and ecological simulations for populations of strategies. With a growing collection of 122 strategies, the library is a also a platform for an original tournament that, in itself, is of interest to the game theoretic community. UP JORS software Latex paper template version 0.1 This paper describes the Iterated Prisoner's Dilemma, the Axelrod library and its development, and insights gained from some novel research. Introduction Several Iterated Prisoner's Dilemma tournaments have generated much interest; including Axelrod's original tournaments [2, 3], two 2004 anniversary tournaments [20], and the Stewart and Plotkin 2012 tournament [42], following the discovery of zero-determinant strategies. Subsequent research has spawned an enormous number of papers , but rarely are the results reproducible. Among well-known tournaments, in only one case is the full original source code available (Axelrod's second tournament [3], in FORTRAN). In no cases is the available code well-documented, easily modifiable, or released with significant test suites. To make matters more complicated, often a newly-created strategy is studied in isolation by opponents chosen by the strategy's creators, and often such strategies are not sufficiently described to enable reliable recreation (in the absence of source code), with [40] being a notable counterexample. In some cases, strategies are revised without updates to their names or published implementations [25, 26]. As a result, some of the results related to these strategies and tournaments cannot be reliably replicated, and therefore have not met the basic scientific criterion of falsifiability. This paper introduces a software package: the Axelrod Python library [43]. The Axelrod-Python project has the following stated goals: • To enable the reproduction of Iterated Prisoner's Dilemma research as easily as possible • To produce the de-facto tool for any future Iterated Prisoner's Dilemma research • To provide as simple a means as possible for anyone to define and contribute new and original Iterated Prisoner's Dilemma strategies The presented library is partly motivated by an ongoing discussion …