Friday 8 July 2011

Darwin: Celebrating 50 Years of Programming Games

screenshot from Darwin-80
Darwin was the earliest programming game, invented by Victor Vyssotsky in August 1961. The idea of the game was to write a program to out-replicate and disable all opponents.

Each program had a number of protected locations and interacted via three functions:

  • PROBE - return the start, end and owner of a memory block
  • CLAIM - reserve memory
  • KILL - disable a program

If a protected location was PROBEd the current program lost control. A CLAIM or KILL could only be used on a location which had previously been PROBEd.

Douglas McIlroy coded Darwin on Bell Labs' IBM 7090 and the game slowly progressed until an unbeatable program emerged, designed by Robert Morris.

Robert's program used an adaptive search. If the program PROBEd an opponent and lost control it would avoid reusing the same offset. A successful offset would be stored then used for future PROBEs and to initialise new copies of itself. Robert's program adapted to become a specialist killer.

In 1972 0 (Aleph-Null) published the rules of Darwin in Software Practice and Experience, inspiring a number of new implementations. In 1987 Gerald Edgar published his 8080 version to accompany an article in Computer Language.

Unfortunately Darwin faced a major problem. Programs were written in machine language and could only compete against others written for the same computer. When A. K. Dewdney introduced Core War in 1984 he addressed the limitation by defining the MARS virtual computer and Redcode, a simplified assembly language.

Although Darwin has been consigned to the history book, I'll never grow tired of reading about it! Do you remember playing Darwin? If so, I'd love to hear the details.


  • 0 "Computer Recreations: Darwin"
    Software: Practice and Experience 2 (Jan-Mar 1972): 93-96.
  • Dewdney, A. K. "In a game called core war hostile programs engage in a battle of bits" Scientific American 250 (May 1984): 14–22.
  • Edgar, Gerald A. "Darwin: A survival game for programmers."
    Computer Language (Apr 1987): 79-86.
  • Levy, Steven Artificial Life: The Quest for a New Creation.
    New York: Pantheon Books, 1992. 317-319.
  • Vyssotsky, Victor A. Darwin: A Game of Survival and (Hopefully) Evolution.
    New Jersey: Bell Telephone Laboratories, 1961.

See Also


  1. Sounds like 'Computer Virus Programming Skills 101' to me....

  2. That's the idea, Francis!

  3. I wish I would have gotten this deep into computer programming and game programming. I've made some good old fashioned games using basic and a few others, and I've experimented a lot with how computers work. But I've never done anything like this. It sounds like some of the best fun.

  4. Is there any replica for that game? I want to try it.

  5. Otli: unfortunately there isn't a modern version of Darwin. :-( The closest is Core War.


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