Roshambo

Topic Editor: Guy Haworth

Contributions are welcome and the ICGA will, with permission, list contributor’s names and email addresses on its Contributor’s page.

Introduction

RoShamBo: a 2-player game of imperfect information where each player has to guess the 3-way choice made by the other from 'R', 'P' and 'S'. In scoring terms R < P < S < R so each choice wins against one other and ties with itself. R, P, S are Rock, Paper, Scissors, the English name for the game. The scoring system is explained by the metaphor "Rock is wrapped in Paper, Paper is cut by Scissors, Scissors go blunt on Rock". 'Roshambo' is phonetic French for 'Rock, Paper, Scissors'.

Roshambo has a simpler 2-choice relative in Heads and Tails or Matching Pennies.  Both players choose Heads or Tails: one person wins if the choices are different, the other if they are the same.

Roshambo is unusual in having no board or pieces, no move which is intrinsically better than any other, and combined rather than alternate play by the two players. There is no opening-, middle- or end-game in the normal sense but rather a comet-tail of historical choices by the two players.

As Shannon is to Computer Chess, Darse Billings is to Computer Roshambo. He devised and organised two highly popular competitions, and summarised his observations in a prize-winning paper in the ICGA Journal. Computer Roshambo has many advantages over Carbon Roshambo:  speed, less opportunity for cheating, and greater ability to analyse the past history.

Events

Future Challenges

  1. Further Computer Roshambo competitions.

  2. Man-Machine Roshambo competitions.

  3. A Computer-Roshambo league on the web.

Relevant Associations

Servers

Key People and Programs

  • Don Beal: author of GENERAL PREDICTOR, 5th in the 2nd IRPC. Also, an ex-Treasurer of the ICCA, now the ICGA.

  • Darse Billings: devisor and organiser of the two IRPCs.

  • Dan Egnor: author of IOCAINE POWDER, 1st in the 1st IRPC and 3rd in the 2nd IRPC.

  • Perry Friedman: author of ROSHAMBOT

  • Jason Hutchens: author of MEGAHAL, 3rd in the 1st IRPC

  • Jakob Mandelson: author of PHASENBOT, 2nd in the 1st IRPC

  • Doug Meserve: author of MEMINATOR, 2nd in the 2nd IRPC - and of MEMBOT, 1st in the mini-bot competition (2000)

  • Andrzej Nagorko: author of GREENBERG, 1st in the 2nd IRPC.

  • Jonathan Schaeffer: author of BIOPIC, ex-Treasurer and Board Member of the ICCA, now the ICGA. Head of the University of Alberta Games Group.

  • Russ Williams: author of RUSSROCKER4, 4th in the 1st IRPC.
  • BIOPIC: 5th in the 1st IRPC.

  • GENERAL PREDICTOR: 5th in the 2nd IRPC.

  • GREENBERG: 1st in the 2nd IRPC.

  • IOCAINE POWDER: 1st in the 1st IRPC. c.f. The Princess Bride for the name origin.

  • LITTLEMEMBOT: a program of 9 'C' statements that would have won the 1st Mini-bot Competition, if entered.

  • MEGAHAL: 3rd in the 1st IRPC.

  • MEMINATOR: 2nd in the 2nd IRPC.

  • MEMBOT: 1st in the 1st Mini-Bot Competition (2000), and 4th in the 2nd IRPC.

  • PHASENBOT: 2nd in the 1st IRPC.

  • ROSHAMBOT: hosts a Roshambo-playing service on the web.

  • RUSSROCKER4: 4th in the 1st IRPC.

References

Books and Papers

  • Billings, D. (2000). Thoughts on RoShamBo. ICGA Journal, Vol. 23, No. 1, pp. 3-8. ISSN 1389-6911.

  • Billings, D. (2000). The First International RoShamBo Programming Competition. ICGA Journal, Vol. 23, No. 1, pp. 42-50.

  • Egnor, D. (2000). Iocaine Powder, ICGA Journal, Vol. 23, No. 1, pp. 33-35.

  • Fudenberg, D. and Levine, D.K. (1998). The Theory of Learning in Games. MIT Press, Cambridge, MA. ISBN 0-2620-6194-5.

  • Goldman, W. (2000). The Princess Bride: S. Morgenstern's Classic Tale of True Love and High Adventure. (The 'Good Parts' Version). Ballantine Books. ISBN 0-3454-3014-X, the 25th Anniversary Edition.

  • Goldman, W. (1987). The Princess Bride. Film directed by Rob Reiner.

  • Goldman, W. (1997). Four Screenplays with Essays: Marathon Man, Butch Cassidy and the Sundance Kid, The Princess Bride, Misery. Applause Theatre Book Pub; ISBN 1-5578-3265-X.

  • Sinervo, B. and Lively, C.M. (1996). The rock-paper-scissors game and the evolution of alternative male strategies. Nature, Vol. 380, pp. 240-243.

  • Tanaka, K. (2001). Physics and Ecology of Rock-Paper-Scissors Game. pp. 384-395 of Computers and Games (eds., T. Marsland and I. Frank), Revised Papers from the Second International on Computers and Games, CG2000, Hamamatsu, Japan. Springer-Verlag. ISBN 3-5404-3080-6. Also designated as LNCS Vol. 2063. ISSN 0302-9743.

Web Sources