Tuesday 5 October 2010

Core War - The King of Programming Games

corewar: the war of the programmers
The aim of a programming game is to write a short program that competes towards a goal, usually destroying all opponents or capturing a flag.

There are two main types of programming game:
  • games inspired by RobotWar - programs control a battle robot which moves around an arena firing at opponents – RobotWar was created in the 1970s.
  • games inspired by Darwin - programs attempt to modify and crash the opponent's program. Darwin was first played at Bell Labs in 1961.

Both games have spawned a series of clones, the most popular being CRobots (1985) and Core War (1984).

In Core War players write programs in Redcode, the assembly language of the MARS virtual computer. The aim of the game is to survive while causing all opponents to terminate. There are three basic strategies:

  • paper - programs spawn off new copies in the hope at least one survives.
  • scissors - programs search for opponents and attempt to disable them.
  • stone - programs drops instructions at random hoping to hit the opponent.

A couple of years after A. K. Dewdney introduced Core War a society was formed which organised an annual tournament. The First International Core War Tournament held in the Computer Museum, Boston MA was a great success with a paper coming out on top, Mice by Chip Wendell.

Core War is now played as a King of the Hill tournament. Players submit their program to a hill containing some of the top Core War programs, receiving results a few minutes later. If the program is successful it enters the hill, knocking off the lowest warrior.

Despite being 26 years old Core War still has a community of regular players. Although the major techniques appear to have been discovered new ideas are constantly being tested, occasionally with impressive results. If you’d like to find out more about Core War here are some handy links for new players:

If you’re planning to try your hand at writing a battle program, good luck and may the core be with you!


  1. In 1985 or 1986 as a high school student in Salem, OR I entered a Core War competition at Portland State University. My program was triumphant and I won an HP 11C calculator which I used all through college and just passed on to my 10 year old. What fun to run across this post!

  2. Is this related to the reference you used later in "A Bibliography of Programming Games", ,

    Cottrell, Jon "Core Wars."
    Your Computer (Sep 1985): 72–74.


  3. http://www.retroprogramming.com/2011/11/bibliography-of-programming-games.html


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