Plagiarism detection in game-playing software

Plagiarism is a growing issue in the field of game-playing software. As new ideas and technologies are successfully implemented in free and commercial programs, they will be reused and revisited by later programs until they become standard, but on the other hand the same phenomenon can lead to accusations and claims of plagiarism, especially in competitive scenarios such as computer chess tournaments. Establishing whether a program is a "clone" or derivative of another can be a difficult and subjective task, left to the judgment of the individual expert and often resulting in a shade of gray rather than black and white verdicts. Tournaments judges and directors have to decide how similar is too similar on a case-by-case basis. This paper presents an objective framework under which similarities between game programs can be judged, using chess as a test case.