This is a page to briefly describe some previous ICCA/ICGA investigations, or more generally, originality and plagiarism in computer boardgames. One purpose for this is to ease the formation of a historical context in any decision process.
In the 9th World Microcomputer Chess Championship (Portorož, 1989), the program Quickstep by Mr. Langer was excluded from further participation after four rounds. The reason was that the program was “an unauthorized version of the Mephisto Almeria program” .
Original Author Programs
For the Triennial World Championship event all participants are required to bring source code of their program. This code must be made available to the Tournament Director (or designate) for scrutiny in case of dispute. The purpose here is to ensure that each program is unique and is owned by the representing programmer. For the Microcomputer events a less stringent standard has been applied, but amateurs must identify the authors of the program they submit. As the number of freely distributed programs grow, or if people start putting their own front end on a commercial product, then it may be necessary to scrutinize the source code of all PC-based programs too, to ascertain that significant changes have been made. In the past the integrity of our participants has rarely been questioned, but the ICCA must always be ready for the day when a serious dispute arises. Scrutinizing the credentials of the designated operator may therefore be part of the application process for future events.
One reason why there have been so few problems to date has been because a member of the design team typically serves as the operator. This meets one of our original objectives, to facilitate the exchange of ideas about chess programming. The use of operators with little knowledge of either chess or programming is therefore discouraged.
The question posed above theoretically has been partially answered in recent practice. In the 14th WMCC (Jakarta, 1996), the Indonesian program GUNDA-1 participated, and in the 16th Open Dutch Computer-Chess Championship (Leiden, 1996) the program RAJAH was entered. Both programs were based on Hyatt's world-wide available code of the program CRAFTY. Since both teams gave due credit to CRAFTY as their original source, it is comparable to using ideas from articles while giving appropriate reference. Nevertheless, the question remains to what extent can we prolong the similarity of publications and programs. For articles, we do not allow plagiarism. For algorithms and programs I believe we are in a state of flux. Yet, the researcher who is the originator of the ideas should always be given pride of place.  
In the 11th WCCC (Graz, 2003) the author of the program List refused inspection of his program code and was banned from the tournament for precisely this reason . Subsequent letters from Reul and Levy were published in the ICGA Journal Vol. 28, No. 1, March 2005  
El Chinito (Chinito played two ICGA tournaments, the WCCC 2002 and 2003 ) was suspected and proved to contain Crafty code in 2004 . Eugenio Castillo Jiménez admitted using Crafty in an open letter and also informed the ICGA .
An overview of the case in computer Go, entitled Plagiarism in Computer Go was given in 2000 by Raymond Keene , and evidence was given by Chen Zhixing . It can also be noted that the long-term effects of this case continue to linger :
It is unknown whether subsequent versions continue to plagiarize, due to anti-tracing measures added to KCC Igo. This stigma extends to the present day; the largely rewritten KCC Igo was denied entry to the 2009 Computer Olympiad.
I could find no independent mention of this 2009 decision, but did find an exchange regarding 2008 participation :
Their registration was rejected because of "past problems with [this] program in other computer Go tournaments" (these are the words of David Levy). The ICGA will make an official statement later. (Rémi Coulom)
It would be nice to track down the official ICGA statement.
- slightly edited version from the ICGA Investigations Wiki, concerning links and headers
- Jaap van den Herik, David Levy (1989). Disqualification at Portorož. ICCA Journal, Vol. 12, No. 4, pp. 232-236
- Tony Marsland (1996). Experience is a Hard Teacher. ICCA Journal, Vol. 19, No. 4
- ICCA Journal, Volume 20: Number 1
- Misinformation about RAJAH in the ICCA by Valavan Manohararajah, rgcc, April 5, 1997
- Valavan Manohararajah (1997) Rajah: The Design of a Chess Program. ICCA Journal, Vol. 20, No. 2, pp. 87-91.
- Omid David (2003). The 11th World Computer-Chess Championship. ICGA Journal, Vol. 26, No. 4, pp. 252-259)
- Fritz Reul (2005) A Letter to the ICGA. ICGA Journal Vol. 28, No. 1 (pdf)
- David Levy (2005) Cancellation of Suspension. ICGA Journal Vol. 28, No. 1 (pdf)
- Jaap van den Herik (2006). The Interpretation of Rules. ICGA Journal Vol. 29, No. 2 (pdf)
- Chinito (ICGA Tournaments)
- List is NOT a Crafty clone, ... etc by Matthias Gemuh, CCC, August 21, 2004
- Open letter by Eugenio Castillo (ELChinito team) ... by Frank Quisinsky, CCC, August 28, 2004
- SquarknII Chess Program Disqualified (ICGA Tournaments)
- Plagiarism in Computer Go by Raymond Keene, April 1, 2000
- Plagiarism from Handtalk by Chen Zhixing, in Chinese, with Western-readable ASM dumps
- Sensei's Library: Silver Star
- Re: [computer-go 2008 Olympiad] by Rémi Coulom, August 21, 2008