by Jan Kristian Haugland © 2001, 2002
Neutreeko is a simple game played on a board with 5×5 squares.
The name is a portmanteau of Neutron and Teeko, two games on which it is based.
Initial setup: The players have three pieces each. They are placed as shown in the figure.
Movement: A piece slides orthogonally or diagonally until stopped by
an occupied square or the border of the board. Black always moves first.
Objective: To get three in a row, orthogonally or diagonally. The row must be connected.
Repetitions: A match is declared a draw if the same position occurs three times.
Tactical depth: There are positions for which perfect play leads to a win in 51 moves (that is,
26 moves by one player and 25 by the other one). Only about 3% of all legal positions are neutral,
including the starting position. These things can be explored with the Neutreeko oracle (see below).
Strategy: Neutreeko is a highly tactical game with little room for long-term strategic planning. But if neither side
has an attack coming up, it can often be a good idea to immobilize your opponent by forcing him into a corner.
Starting position dilemma: The starting position was chosen so as to avoid a short distance to a "draw-loop",
but the disadvantage is that there is essentially only one way to play the first 15 moves correctly, which
of course can be memorized. In the unlikely event that someone wants to arrange serious competitions
in this game, it may be necessary to somehow generate a new starting position for each match.
Dao: When I first announced Neutreeko on usenet in 2001, I learned that a game with very similar rules, Dao, had
already been published. However, compared to Neutreeko, Dao appears to be drawish and to lack tactical depth.
Perfect opening play
External links: http://hrx.free.fr (download program)
http://www.iggamecenter.com (play online)
Neutreeko oracle (in java, not compiled)
Neutreeko oracle (in Python)
Oracles for other board games